darifenacin (Rx)

Overactive Bladder

Indicated for overactive bladder with symptoms of urge incontinence, urgency, and frequency

Initial: 7.5 mg PO qDay

May be increased to 15 mg based on patient response as early as 2 weeks later

Do not increase dose if taking concomitant CYP3A4 inhibitors

Hepatic Impairment

Moderate: Do not exceed initial dose of 7.5 mg/day

Severe: Not recommended

Administration

Swallow with water, do not crush, chew or cut

Safety and efficacy not established

Contraindicated (1)

• eliglustat

  darifenacin increases levels of eliglustat by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated. If coadministered with strong or moderate CYP2D6 inhibitors, reduce eliglustat dose from 84 mg BID to 84 mg once daily in extensive and intermediate metabolizers; eliglustat is contraindiated if strong or moderate CYP2D6 inhibitors are given concomitantly with strong or moderate CYP3A inhibitors.

Serious - Use Alternative (45)

• abametapir

  abametapir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.

• apalutamide

  apalutamide will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

• carbamazepine

  carbamazepine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• chloramphenicol

  chloramphenicol will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• cimetidine

  cimetidine will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• clarithromycin

  clarithromycin will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• dihydroergotamine

  darifenacin will increase the level or effect of dihydroergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• dihydroergotamine intranasal

  darifenacin will increase the level or effect of dihydroergotamine intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• dronedarone

  darifenacin will increase the level or effect of dronedarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ergotamine

  darifenacin will increase the level or effect of ergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin base

  darifenacin will increase the level or effect of erythromycin base by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  erythromycin base will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin ethylsuccinate

  erythromycin ethylsuccinate will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  darifenacin will increase the level or effect of erythromycin ethylsuccinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin lactobionate

  erythromycin lactobionate will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  darifenacin will increase the level or effect of erythromycin lactobionate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin stearate

  erythromycin stearate will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  darifenacin will increase the level or effect of erythromycin stearate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• everolimus

  darifenacin will increase the level or effect of everolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• fexinidazole

  fexinidazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

• glycopyrronium tosylate topical

  glycopyrronium tosylate topical, darifenacin. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration of glycopyrronium tosylate topical with other anticholinergic medications may result in additive anticholinergic adverse effects.

• idelalisib

  idelalisib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

• indinavir

  indinavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• itraconazole

  itraconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Not recommended during and 2 weeks after itraconazole.

• ivosidenib

  ivosidenib will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternate therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

• ketoconazole

  ketoconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• levoketoconazole

  levoketoconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• lonafarnib

  darifenacin will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of lonafarnib (a sensitive CYP3A substrate) with weak CYP3A inhibitors is unavoidable, reduce to, or continue lonafarnib at starting dose. Closely monitor for arrhythmias and events (eg, syncope, heart palpitations) since lonafarnib effect on QT interval is unknown.
  
  lonafarnib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.

• lopinavir

  lopinavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• lovastatin

  darifenacin will increase the level or effect of lovastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• nefazodone

  nefazodone will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• pazopanib

  darifenacin will increase the level or effect of pazopanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of pazopanib with strong CYP3A4 inhibitors if possible; if must coadminister, decrease pazopanib dose to 400 mg/day

• pimozide

  darifenacin increases levels of pimozide by decreasing metabolism. Contraindicated. Risk of QT interval prolongation.

• pramlintide

  pramlintide, darifenacin. Either increases effects of the other by pharmacodynamic synergism. Contraindicated. Synergistic inhibition of GI motility.

• ranolazine

  darifenacin will increase the level or effect of ranolazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• revefenacin

  revefenacin and darifenacin both decrease cholinergic effects/transmission. Avoid or Use Alternate Drug. Coadministration may cause additive anticholinergic effects.

• ribociclib

  ribociclib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rifabutin

  rifabutin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rifampin

  rifampin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• secretin

  darifenacin decreases effects of secretin by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Concomitant use of anticholinergic drugs may cause a hyporesponse to stimulation testing with secretin. Discontinue anticholinergic drugs at least 5 half-lives before administering secretin.

• silodosin

  darifenacin will increase the level or effect of silodosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• simvastatin

  darifenacin will increase the level or effect of simvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• sirolimus

  darifenacin will increase the level or effect of sirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• St John's Wort

  St John's Wort will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• thioridazine

  darifenacin will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

• tolvaptan

  darifenacin will increase the level or effect of tolvaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• tucatinib

  tucatinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

• umeclidinium bromide/vilanterol inhaled

  darifenacin, umeclidinium bromide/vilanterol inhaled. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Concomitant use with other anticholinergic-containing drugs may lead to additive anticholinergic adverse effects.

• voxelotor

  voxelotor will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

Monitor Closely (251)

• abobotulinumtoxinA

  abobotulinumtoxinA increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects. .

• aclidinium

  darifenacin and aclidinium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• almotriptan

  darifenacin will increase the level or effect of almotriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• alprazolam

  darifenacin will increase the level or effect of alprazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• amantadine

  darifenacin, amantadine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Potential for increased anticholinergic adverse effects.

• amiodarone

  darifenacin will increase the level or effect of amiodarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• amitriptyline

  darifenacin will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin and amitriptyline both decrease cholinergic effects/transmission. Modify Therapy/Monitor Closely.

• amobarbital

  amobarbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• amoxapine

  darifenacin and amoxapine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• anticholinergic/sedative combos

  anticholinergic/sedative combos and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• aprepitant

  aprepitant will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of aprepitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• aripiprazole

  darifenacin will increase the level or effect of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin decreases levels of aripiprazole by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of aripiprazole by pharmacodynamic antagonism. Use Caution/Monitor.
  
  aripiprazole increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• armodafinil

  armodafinil will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• artemether/lumefantrine

  artemether/lumefantrine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of artemether/lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• atazanavir

  atazanavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• atogepant

  darifenacin will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• atomoxetine

  darifenacin will increase the level or effect of atomoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• atorvastatin

  darifenacin will increase the level or effect of atorvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• atracurium

  atracurium and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• atropine

  atropine and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• atropine IV/IM

  atropine IV/IM and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• avapritinib

  darifenacin will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• axitinib

  darifenacin increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• bazedoxifene/conjugated estrogens

  darifenacin will increase the level or effect of bazedoxifene/conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• belladonna alkaloids

  belladonna alkaloids and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• belladonna and opium

  darifenacin and belladonna and opium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• belzutifan

  belzutifan will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If unable to avoid coadministration of belzutifan with sensitive CYP3A4 substrates, consider increasing the sensitive CYP3A4 substrate dose in accordance with its prescribing information.

• benperidol

  darifenacin decreases levels of benperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of benperidol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  benperidol increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• benzhydrocodone/acetaminophen

  darifenacin will increase the level or effect of benzhydrocodone/acetaminophen by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone [benzhydrocodone is prodrug of hydrocodone]) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone.

• benztropine

  benztropine and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor. Additive anticholinergic adverse effects may be seen with concurrent use.

• bethanechol

  bethanechol increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• bosentan

  bosentan will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• brexpiprazole

  darifenacin will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP2D6 inhibitor PLUS a strong/moderate CYP3A4 inhibitor.

• budesonide

  darifenacin will increase the level or effect of budesonide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• buspirone

  darifenacin will increase the level or effect of buspirone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• butabarbital

  butabarbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• butalbital

  butalbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• carbachol

  carbachol increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• carbamazepine

  darifenacin will increase the level or effect of carbamazepine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• carvedilol

  darifenacin will increase the level or effect of carvedilol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• cenobamate

  cenobamate will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.

• ceritinib

  ceritinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cevimeline

  cevimeline increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• chlorpromazine

  darifenacin decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• cilostazol

  darifenacin will increase the level or effect of cilostazol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cinacalcet

  darifenacin will increase the level or effect of cinacalcet by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cisatracurium

  cisatracurium and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• clomipramine

  darifenacin will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of clomipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin and clomipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• clopidogrel

  darifenacin will decrease the level or effect of clopidogrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Inhibition of CYP3A4 will reduce clopidogrel bioactivation

• clozapine

  darifenacin will increase the level or effect of clozapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin decreases levels of clozapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of clozapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  clozapine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• cobicistat

  cobicistat will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Darifenacin daily dose should not exceed 7.5 mg PO when administered concomitantly.

• codeine

  darifenacin decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.

• conivaptan

  conivaptan will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of conivaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• conjugated estrogens

  darifenacin will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• conjugated estrogens, vaginal

  darifenacin will increase the level or effect of conjugated estrogens, vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cortisone

  darifenacin will increase the level or effect of cortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• crizotinib

  crizotinib increases levels of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.

• crofelemer

  crofelemer increases levels of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.

• cyclizine

  cyclizine and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• cyclobenzaprine

  cyclobenzaprine and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• cyclosporine

  cyclosporine will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dabrafenib

  dabrafenib will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

• darunavir

  darifenacin will increase the level or effect of darunavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darunavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dasatinib

  darifenacin will increase the level or effect of dasatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  dasatinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• deferasirox

  deferasirox will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• desipramine

  darifenacin will increase the level or effect of desipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of desipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dexamethasone

  darifenacin will increase the level or effect of dexamethasone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• DHEA, herbal

  DHEA, herbal will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• diazepam

  darifenacin will increase the level or effect of diazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dicyclomine

  darifenacin and dicyclomine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• digoxin

  darifenacin increases levels of digoxin by unspecified interaction mechanism. Use Caution/Monitor.

• diltiazem

  diltiazem will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• diphenhydramine

  darifenacin and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• donepezil

  donepezil increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• donepezil transdermal

  donepezil transdermal, darifenacin. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor.

• dosulepin

  darifenacin and dosulepin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• doxepin

  darifenacin will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• dronedarone

  dronedarone will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• droperidol

  darifenacin decreases levels of droperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of droperidol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  droperidol increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• duloxetine

  darifenacin will increase the level or effect of duloxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• duvelisib

  duvelisib will increase the level or effect of darifenacin by affecting hepatic enzyme CYP2E1 metabolism. Modify Therapy/Monitor Closely. will increase the level or effect of

• echothiophate iodide

  echothiophate iodide increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• efavirenz

  efavirenz will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• elagolix

  elagolix will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

• eletriptan

  darifenacin will increase the level or effect of eletriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

• encorafenib

  encorafenib, darifenacin. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.

• enzalutamide

  enzalutamide will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• erlotinib

  darifenacin will increase the level or effect of erlotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• eslicarbazepine acetate

  eslicarbazepine acetate will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• estradiol

  darifenacin will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• estrogens conjugated synthetic

  darifenacin will increase the level or effect of estrogens conjugated synthetic by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• estrogens esterified

  darifenacin will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• estropipate

  darifenacin will increase the level or effect of estropipate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• etonogestrel

  darifenacin will increase the level or effect of etonogestrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• etravirine

  darifenacin will increase the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  etravirine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fedratinib

  fedratinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• felodipine

  darifenacin will increase the level or effect of felodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fesoterodine

  darifenacin will increase the level or effect of fesoterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin and fesoterodine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• finerenone

  darifenacin will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or weak CYP3A4 inhibitors. Adjust finererone dosage as needed.

• flavoxate

  darifenacin and flavoxate both decrease cholinergic effects/transmission. Use Caution/Monitor.

• flecainide

  darifenacin will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• flibanserin

  darifenacin will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors.

• fluconazole

  fluconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fludrocortisone

  darifenacin will increase the level or effect of fludrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fluphenazine

  darifenacin decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  fluphenazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• fluvoxamine

  fluvoxamine will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosamprenavir

  darifenacin will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  fosamprenavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosaprepitant

  fosaprepitant will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of fosaprepitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosphenytoin

  fosphenytoin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• galantamine

  galantamine increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• glycopyrrolate

  darifenacin and glycopyrrolate both decrease cholinergic effects/transmission. Use Caution/Monitor.

• glycopyrrolate inhaled

  darifenacin and glycopyrrolate inhaled both decrease cholinergic effects/transmission. Use Caution/Monitor.

• grapefruit

  grapefruit will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• griseofulvin

  griseofulvin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• haloperidol

  darifenacin will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  haloperidol increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• henbane

  darifenacin and henbane both decrease cholinergic effects/transmission. Use Caution/Monitor.

• homatropine

  darifenacin and homatropine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• huperzine A

  huperzine A increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• hydrocodone

  darifenacin will increase the level or effect of hydrocodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone.

• hydrocortisone

  darifenacin will increase the level or effect of hydrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• hydromorphone

  darifenacin will increase the level or effect of hydromorphone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• hydroxyprogesterone caproate

  darifenacin will increase the level or effect of hydroxyprogesterone caproate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• hyoscyamine

  darifenacin and hyoscyamine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• hyoscyamine spray

  darifenacin and hyoscyamine spray both decrease cholinergic effects/transmission. Use Caution/Monitor.

• iloperidone

  darifenacin will increase the level or effect of iloperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of iloperidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin decreases levels of iloperidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of iloperidone by pharmacodynamic antagonism. Use Caution/Monitor.
  
  iloperidone increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  iloperidone increases levels of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.

• imipramine

  darifenacin will increase the level or effect of imipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of imipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin and imipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• indinavir

  darifenacin will increase the level or effect of indinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ipratropium

  darifenacin and ipratropium both decrease cholinergic effects/transmission. Use Caution/Monitor. Due to the poor systemic absorption of ipratropium, interaction unlikely at regularly recommended dosages.

• isavuconazonium sulfate

  darifenacin will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• isoniazid

  isoniazid will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• istradefylline

  istradefylline will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.

• ixabepilone

  darifenacin will increase the level or effect of ixabepilone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• lapatinib

  darifenacin will increase the level or effect of lapatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  lapatinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• lemborexant

  darifenacin will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.

• lenacapavir

  lenacapavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir (a moderate CYP3A4 inhibitor) may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.

• letermovir

  letermovir increases levels of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• lofepramine

  darifenacin will increase the level or effect of lofepramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin and lofepramine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• lomitapide

  darifenacin increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.

• lopinavir

  darifenacin will increase the level or effect of lopinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• loratadine

  darifenacin will increase the level or effect of loratadine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• lorlatinib

  lorlatinib will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• loxapine

  darifenacin decreases levels of loxapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of loxapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  loxapine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• loxapine inhaled

  loxapine inhaled increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  darifenacin decreases levels of loxapine inhaled by pharmacodynamic antagonism. Use Caution/Monitor.

• lumefantrine

  darifenacin will increase the level or effect of lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  lumefantrine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• maprotiline

  darifenacin and maprotiline both decrease cholinergic effects/transmission. Use Caution/Monitor.

• maraviroc

  darifenacin will increase the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• marijuana

  marijuana will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• meclizine

  darifenacin and meclizine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• mestranol

  darifenacin will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• methadone

  darifenacin will increase the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• methamphetamine

  darifenacin will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• methscopolamine

  darifenacin and methscopolamine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• methylprednisolone

  darifenacin will increase the level or effect of methylprednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• metoprolol

  darifenacin will increase the level or effect of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• metronidazole

  metronidazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mexiletine

  darifenacin will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• miconazole vaginal

  miconazole vaginal will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• midazolam

  darifenacin will increase the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• midazolam intranasal

  darifenacin will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.

• mifepristone

  mifepristone will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. In adults receiving mifepristone chronically for treatment of hormonal conditions, daily dose of darifenacin should not exceed 7.5 mg/day PO

• mitotane

  mitotane decreases levels of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.

• morphine

  darifenacin will increase the level or effect of morphine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• nafcillin

  nafcillin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inducers may increase metabolism of CYP3A4 substrates

• nebivolol

  darifenacin will increase the level or effect of nebivolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• nelfinavir

  darifenacin will increase the level or effect of nelfinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nelfinavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• neostigmine

  neostigmine increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• nevirapine

  nevirapine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• nicardipine

  darifenacin will increase the level or effect of nicardipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• nifedipine

  nifedipine will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• nilotinib

  darifenacin will increase the level or effect of nilotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nilotinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• nisoldipine

  darifenacin will increase the level or effect of nisoldipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• nortriptyline

  darifenacin will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.

• olanzapine

  darifenacin decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oliceridine

  darifenacin will increase the level or effect of oliceridine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. If concomitant use is necessary, may require less frequent oliceridine dosing. Closely monitor for respiratory depression and sedation and titrate subsequent doses accordingly. If inhibitor is discontinued, consider increase oliceridine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal.
  
  darifenacin increases toxicity of oliceridine by Other (see comment). Use Caution/Monitor. Comment: Anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Monitor for signs of urinary retention or reduced gastric motility if oliceridine is coadministered with anticholinergics.

• onabotulinumtoxinA

  onabotulinumtoxinA and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• orphenadrine

  darifenacin and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• oxcarbazepine

  oxcarbazepine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• oxybutynin

  darifenacin and oxybutynin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• oxybutynin topical

  darifenacin and oxybutynin topical both decrease cholinergic effects/transmission. Use Caution/Monitor.

• oxybutynin transdermal

  darifenacin and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.

• oxycodone

  darifenacin will increase the level or effect of oxycodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• oxymorphone

  darifenacin will increase the level or effect of oxymorphone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• paliperidone

  darifenacin decreases levels of paliperidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of paliperidone by pharmacodynamic antagonism. Use Caution/Monitor.
  
  paliperidone increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• pancuronium

  darifenacin and pancuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• pentobarbital

  pentobarbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• perphenazine

  darifenacin decreases levels of perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  perphenazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• phenobarbital

  phenobarbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• phenytoin

  phenytoin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• physostigmine

  physostigmine increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• pilocarpine

  pilocarpine increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• pimozide

  darifenacin decreases levels of pimozide by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of pimozide by pharmacodynamic antagonism. Use Caution/Monitor.
  
  pimozide increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• posaconazole

  posaconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• prabotulinumtoxinA

  darifenacin, prabotulinumtoxinA. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.

• pralidoxime

  darifenacin and pralidoxime both decrease cholinergic effects/transmission. Use Caution/Monitor.

• prednisone

  darifenacin will increase the level or effect of prednisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• primidone

  primidone will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• prochlorperazine

  darifenacin decreases levels of prochlorperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of prochlorperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  prochlorperazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• promethazine

  darifenacin decreases levels of promethazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of promethazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  promethazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• propafenone

  darifenacin will increase the level or effect of propafenone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• propantheline

  darifenacin and propantheline both decrease cholinergic effects/transmission. Use Caution/Monitor.

• propranolol

  darifenacin will increase the level or effect of propranolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• protriptyline

  darifenacin and protriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.

• pyridostigmine

  pyridostigmine increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• quetiapine

  darifenacin will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  quetiapine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• quinidine

  darifenacin will increase the level or effect of quinidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• quinupristin/dalfopristin

  quinupristin/dalfopristin will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rapacuronium

  darifenacin and rapacuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• repaglinide

  darifenacin will increase the level or effect of repaglinide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rifapentine

  rifapentine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• risperidone

  darifenacin decreases levels of risperidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of risperidone by pharmacodynamic antagonism. Use Caution/Monitor.
  
  risperidone increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• ritonavir

  darifenacin will increase the level or effect of ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  ritonavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rivastigmine

  darifenacin decreases effects of rivastigmine by cholinergic effects/transmission. Use Caution/Monitor.

• rocuronium

  darifenacin and rocuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• rucaparib

  rucaparib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

• rufinamide

  rufinamide will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• saquinavir

  darifenacin will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• scopolamine

  darifenacin and scopolamine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• secobarbital

  secobarbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• solifenacin

  darifenacin will increase the level or effect of solifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin and solifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• stiripentol

  stiripentol, darifenacin. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.

• succinylcholine

  succinylcholine increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• sunitinib

  darifenacin will increase the level or effect of sunitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tacrolimus

  darifenacin will increase the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tamsulosin

  darifenacin increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• tazemetostat

  tazemetostat will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tecovirimat

  tecovirimat will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

• temsirolimus

  darifenacin will increase the level or effect of temsirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• theophylline

  darifenacin will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• thioridazine

  darifenacin decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  thioridazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• thiothixene

  darifenacin decreases levels of thiothixene by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of thiothixene by pharmacodynamic antagonism. Use Caution/Monitor.
  
  thiothixene increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• timolol

  darifenacin will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• tinidazole

  darifenacin will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tiotropium

  darifenacin and tiotropium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• tipranavir

  darifenacin will increase the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  tipranavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tolterodine

  darifenacin will increase the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin and tolterodine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• topiramate

  topiramate will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• trazodone

  darifenacin will increase the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• triamcinolone acetonide injectable suspension

  darifenacin will increase the level or effect of triamcinolone acetonide injectable suspension by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• triazolam

  darifenacin will increase the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• trifluoperazine

  darifenacin decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• trihexyphenidyl

  darifenacin and trihexyphenidyl both decrease cholinergic effects/transmission. Use Caution/Monitor. Potential for additive anticholinergic effects.

• trimipramine

  darifenacin and trimipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• trospium chloride

  darifenacin and trospium chloride both decrease cholinergic effects/transmission. Use Caution/Monitor.

• vardenafil

  darifenacin will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• vecuronium

  darifenacin and vecuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• verapamil

  darifenacin will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• voriconazole

  voriconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• zafirlukast

  zafirlukast will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ziprasidone

  darifenacin decreases levels of ziprasidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of ziprasidone by pharmacodynamic antagonism. Use Caution/Monitor.
  
  ziprasidone increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• zotepine

  darifenacin decreases levels of zotepine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of zotepine by pharmacodynamic antagonism. Use Caution/Monitor.

Minor (81)

• acetazolamide

  acetazolamide will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alfentanil

  darifenacin will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alfuzosin

  darifenacin will increase the level or effect of alfuzosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alosetron

  darifenacin will increase the level or effect of alosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• anastrozole

  anastrozole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• aripiprazole

  darifenacin will increase the level or effect of aripiprazole by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• armodafinil

  darifenacin will increase the level or effect of armodafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• atazanavir

  darifenacin will increase the level or effect of atazanavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• bosentan

  darifenacin will increase the level or effect of bosentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• cevimeline

  darifenacin will increase the level or effect of cevimeline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• chlorpromazine

  darifenacin will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• clarithromycin

  darifenacin will increase the level or effect of clarithromycin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• cyclophosphamide

  cyclophosphamide will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• dapsone

  darifenacin will increase the level or effect of dapsone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• desipramine

  darifenacin and desipramine both decrease cholinergic effects/transmission. Minor/Significance Unknown.

• dexfenfluramine

  darifenacin will increase the level or effect of dexfenfluramine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• dextroamphetamine

  darifenacin will increase the level or effect of dextroamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• dextromethorphan

  darifenacin will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• dimenhydrinate

  dimenhydrinate increases toxicity of darifenacin by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• disopyramide

  darifenacin will increase the level or effect of disopyramide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• docetaxel

  darifenacin will increase the level or effect of docetaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• donepezil

  darifenacin will increase the level or effect of donepezil by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
  
  darifenacin will increase the level or effect of donepezil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  donepezil decreases effects of darifenacin by pharmacodynamic antagonism. Minor/Significance Unknown.

• dutasteride

  darifenacin will increase the level or effect of dutasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• efavirenz

  darifenacin will increase the level or effect of efavirenz by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• encainide

  darifenacin will increase the level or effect of encainide by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• eplerenone

  darifenacin will increase the level or effect of eplerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• esomeprazole

  darifenacin will decrease the level or effect of esomeprazole by Other (see comment). Minor/Significance Unknown. Effectiveness of proton pump inhibitors may be decreased theoretically if administered with other antisecretory agents

• eucalyptus

  darifenacin will increase the level or effect of eucalyptus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• fesoterodine

  darifenacin will increase the level or effect of fesoterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• finasteride

  darifenacin will increase the level or effect of finasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• fluoxetine

  darifenacin will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• fluphenazine

  darifenacin will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• galantamine

  darifenacin will increase the level or effect of galantamine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
  
  darifenacin will increase the level or effect of galantamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  galantamine decreases effects of darifenacin by pharmacodynamic antagonism. Minor/Significance Unknown.

• imatinib

  darifenacin will increase the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• isradipine

  darifenacin will increase the level or effect of isradipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ketoconazole

  darifenacin will increase the level or effect of ketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• lansoprazole

  darifenacin decreases effects of lansoprazole by Other (see comment). Minor/Significance Unknown. Comment: Effectiveness of proton pump inhibitors may be decreased theoretically if administered with other antisecretory agents.

• larotrectinib

  larotrectinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• levodopa

  darifenacin, levodopa. Other (see comment). Minor/Significance Unknown. Comment: Anticholinergic agents may enhance the therapeutic effects of levodopa; however, anticholinergic agents can exacerbate tardive dyskinesia. In high dosage, anticholinergics may decrease the effects of levodopa by delaying its GI absorption. .

• levoketoconazole

  darifenacin will increase the level or effect of levoketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• loratadine

  darifenacin will increase the level or effect of loratadine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• montelukast

  darifenacin will increase the level or effect of montelukast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nifedipine

  darifenacin will increase the level or effect of nifedipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nimodipine

  darifenacin will increase the level or effect of nimodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nitrendipine

  darifenacin will increase the level or effect of nitrendipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• omeprazole

  darifenacin will decrease the level or effect of omeprazole by Other (see comment). Minor/Significance Unknown. Effectiveness of proton pump inhibitors may be decreased theoretically if administered with other antisecretory agents

• oxybutynin

  darifenacin will increase the level or effect of oxybutynin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• paclitaxel

  darifenacin will increase the level or effect of paclitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• paclitaxel protein bound

  darifenacin will increase the level or effect of paclitaxel protein bound by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• pantoprazole

  darifenacin decreases effects of pantoprazole by Other (see comment). Minor/Significance Unknown. Comment: Effectiveness of proton pump inhibitors may be decreased theoretically if administered with other antisecretory agents .

• parecoxib

  darifenacin will increase the level or effect of parecoxib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• paroxetine

  darifenacin will increase the level or effect of paroxetine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• perhexiline

  darifenacin will increase the level or effect of perhexiline by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• perphenazine

  darifenacin will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• pimozide

  darifenacin will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• pioglitazone

  darifenacin will increase the level or effect of pioglitazone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• prochlorperazine

  darifenacin will increase the level or effect of prochlorperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• promazine

  darifenacin will increase the level or effect of promazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• promethazine

  darifenacin will increase the level or effect of promethazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• propafenone

  darifenacin will increase the level or effect of propafenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• quinine

  darifenacin will increase the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• rabeprazole

  darifenacin decreases effects of rabeprazole by Other (see comment). Minor/Significance Unknown. Comment: Effectiveness of proton pump inhibitors may be decreased theoretically if administered with other antisecretory agents.

• ramelteon

  darifenacin will increase the level or effect of ramelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• risperidone

  darifenacin will increase the level or effect of risperidone by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• ruxolitinib

  darifenacin will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ruxolitinib topical

  darifenacin will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• saxagliptin

  darifenacin will increase the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• sufentanil

  darifenacin will increase the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• tolterodine

  darifenacin will increase the level or effect of tolterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• tramadol

  darifenacin will increase the level or effect of tramadol by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• trazodone

  darifenacin and trazodone both decrease cholinergic effects/transmission. Minor/Significance Unknown.

• trifluoperazine

  darifenacin will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• tropisetron

  darifenacin will increase the level or effect of tropisetron by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• vinblastine

  darifenacin will increase the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vincristine

  darifenacin will increase the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vincristine liposomal

  darifenacin will increase the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vinorelbine

  darifenacin will increase the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zaleplon

  darifenacin will increase the level or effect of zaleplon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ziprasidone

  darifenacin will increase the level or effect of ziprasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zolpidem

  darifenacin will increase the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zonisamide

  darifenacin will increase the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• abametapir

  Serious - Use Alternative (1)abametapir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.

• abobotulinumtoxinA

  Monitor Closely (1)abobotulinumtoxinA increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects. .

• acetazolamide

  Minor (1)acetazolamide will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• aclidinium

  Monitor Closely (1)darifenacin and aclidinium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• alfentanil

  Minor (1)darifenacin will increase the level or effect of alfentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alfuzosin

  Minor (1)darifenacin will increase the level or effect of alfuzosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• almotriptan

  Monitor Closely (1)darifenacin will increase the level or effect of almotriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• alosetron

  Minor (1)darifenacin will increase the level or effect of alosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• alprazolam

  Monitor Closely (1)darifenacin will increase the level or effect of alprazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• amantadine

  Monitor Closely (1)darifenacin, amantadine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Potential for increased anticholinergic adverse effects.

• amiodarone

  Monitor Closely (1)darifenacin will increase the level or effect of amiodarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• amitriptyline

  Monitor Closely (2)darifenacin and amitriptyline both decrease cholinergic effects/transmission. Modify Therapy/Monitor Closely.
  
  darifenacin will increase the level or effect of amitriptyline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• amobarbital

  Monitor Closely (1)amobarbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• amoxapine

  Monitor Closely (1)darifenacin and amoxapine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• anastrozole

  Minor (1)anastrozole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• anticholinergic/sedative combos

  Monitor Closely (1)anticholinergic/sedative combos and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• apalutamide

  Serious - Use Alternative (1)apalutamide will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.

• aprepitant

  Monitor Closely (2)aprepitant will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of aprepitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• aripiprazole

  Monitor Closely (4)darifenacin will increase the level or effect of aripiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin decreases levels of aripiprazole by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of aripiprazole by pharmacodynamic antagonism. Use Caution/Monitor.
  
  aripiprazole increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of aripiprazole by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• armodafinil

  Monitor Closely (1)armodafinil will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)darifenacin will increase the level or effect of armodafinil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• artemether/lumefantrine

  Monitor Closely (2)artemether/lumefantrine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of artemether/lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• atazanavir

  Monitor Closely (1)atazanavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)darifenacin will increase the level or effect of atazanavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• atogepant

  Monitor Closely (1)darifenacin will increase the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• atomoxetine

  Monitor Closely (1)darifenacin will increase the level or effect of atomoxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• atorvastatin

  Monitor Closely (1)darifenacin will increase the level or effect of atorvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• atracurium

  Monitor Closely (1)atracurium and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• atropine

  Monitor Closely (1)atropine and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• atropine IV/IM

  Monitor Closely (1)atropine IV/IM and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• avapritinib

  Monitor Closely (1)darifenacin will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• axitinib

  Monitor Closely (1)darifenacin increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• bazedoxifene/conjugated estrogens

  Monitor Closely (1)darifenacin will increase the level or effect of bazedoxifene/conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• belladonna alkaloids

  Monitor Closely (1)belladonna alkaloids and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• belladonna and opium

  Monitor Closely (1)darifenacin and belladonna and opium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• belzutifan

  Monitor Closely (1)belzutifan will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. If unable to avoid coadministration of belzutifan with sensitive CYP3A4 substrates, consider increasing the sensitive CYP3A4 substrate dose in accordance with its prescribing information.

• benperidol

  Monitor Closely (3)darifenacin decreases levels of benperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of benperidol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  benperidol increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• benzhydrocodone/acetaminophen

  Monitor Closely (1)darifenacin will increase the level or effect of benzhydrocodone/acetaminophen by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone [benzhydrocodone is prodrug of hydrocodone]) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone.

• benztropine

  Monitor Closely (1)benztropine and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor. Additive anticholinergic adverse effects may be seen with concurrent use.

• bethanechol

  Monitor Closely (1)bethanechol increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• bosentan

  Monitor Closely (1)bosentan will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)darifenacin will increase the level or effect of bosentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• brexpiprazole

  Monitor Closely (1)darifenacin will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP2D6 inhibitor PLUS a strong/moderate CYP3A4 inhibitor.

• budesonide

  Monitor Closely (1)darifenacin will increase the level or effect of budesonide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• buspirone

  Monitor Closely (1)darifenacin will increase the level or effect of buspirone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• butabarbital

  Monitor Closely (1)butabarbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• butalbital

  Monitor Closely (1)butalbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• carbachol

  Monitor Closely (1)carbachol increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• carbamazepine

  Monitor Closely (1)darifenacin will increase the level or effect of carbamazepine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)carbamazepine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• carvedilol

  Monitor Closely (1)darifenacin will increase the level or effect of carvedilol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• cenobamate

  Monitor Closely (1)cenobamate will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.

• ceritinib

  Monitor Closely (1)ceritinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cevimeline

  Monitor Closely (1)cevimeline increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)darifenacin will increase the level or effect of cevimeline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• chloramphenicol

  Serious - Use Alternative (1)chloramphenicol will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• chlorpromazine

  Monitor Closely (3)darifenacin decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  chlorpromazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of chlorpromazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• cilostazol

  Monitor Closely (1)darifenacin will increase the level or effect of cilostazol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cimetidine

  Serious - Use Alternative (1)cimetidine will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• cinacalcet

  Monitor Closely (1)darifenacin will increase the level or effect of cinacalcet by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cisatracurium

  Monitor Closely (1)cisatracurium and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• clarithromycin

  Serious - Use Alternative (1)clarithromycin will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.Minor (1)darifenacin will increase the level or effect of clarithromycin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• clomipramine

  Monitor Closely (3)darifenacin and clomipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of clomipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• clopidogrel

  Monitor Closely (1)darifenacin will decrease the level or effect of clopidogrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Inhibition of CYP3A4 will reduce clopidogrel bioactivation

• clozapine

  Monitor Closely (4)darifenacin will increase the level or effect of clozapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin decreases levels of clozapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of clozapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  clozapine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• cobicistat

  Monitor Closely (1)cobicistat will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Darifenacin daily dose should not exceed 7.5 mg PO when administered concomitantly.

• codeine

  Monitor Closely (1)darifenacin decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.

• conivaptan

  Monitor Closely (2)conivaptan will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of conivaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• conjugated estrogens

  Monitor Closely (1)darifenacin will increase the level or effect of conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• conjugated estrogens, vaginal

  Monitor Closely (1)darifenacin will increase the level or effect of conjugated estrogens, vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• cortisone

  Monitor Closely (1)darifenacin will increase the level or effect of cortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• crizotinib

  Monitor Closely (1)crizotinib increases levels of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dose reduction may be needed for coadministered drugs that are predominantly metabolized by CYP3A.

• crofelemer

  Monitor Closely (1)crofelemer increases levels of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.

• cyclizine

  Monitor Closely (1)cyclizine and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• cyclobenzaprine

  Monitor Closely (1)cyclobenzaprine and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• cyclophosphamide

  Minor (1)cyclophosphamide will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• cyclosporine

  Monitor Closely (1)cyclosporine will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dabrafenib

  Monitor Closely (1)dabrafenib will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

• dapsone

  Minor (1)darifenacin will increase the level or effect of dapsone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• darunavir

  Monitor Closely (2)darifenacin will increase the level or effect of darunavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darunavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dasatinib

  Monitor Closely (2)darifenacin will increase the level or effect of dasatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  dasatinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• deferasirox

  Monitor Closely (1)deferasirox will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• desipramine

  Monitor Closely (2)darifenacin will increase the level or effect of desipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of desipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)darifenacin and desipramine both decrease cholinergic effects/transmission. Minor/Significance Unknown.

• dexamethasone

  Monitor Closely (1)darifenacin will increase the level or effect of dexamethasone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dexfenfluramine

  Minor (1)darifenacin will increase the level or effect of dexfenfluramine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• dextroamphetamine

  Minor (1)darifenacin will increase the level or effect of dextroamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• dextromethorphan

  Minor (1)darifenacin will increase the level or effect of dextromethorphan by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• DHEA, herbal

  Monitor Closely (1)DHEA, herbal will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• diazepam

  Monitor Closely (1)darifenacin will increase the level or effect of diazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dicyclomine

  Monitor Closely (1)darifenacin and dicyclomine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• digoxin

  Monitor Closely (1)darifenacin increases levels of digoxin by unspecified interaction mechanism. Use Caution/Monitor.

• dihydroergotamine

  Serious - Use Alternative (1)darifenacin will increase the level or effect of dihydroergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• dihydroergotamine intranasal

  Serious - Use Alternative (1)darifenacin will increase the level or effect of dihydroergotamine intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• diltiazem

  Monitor Closely (1)diltiazem will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• dimenhydrinate

  Minor (1)dimenhydrinate increases toxicity of darifenacin by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• diphenhydramine

  Monitor Closely (1)darifenacin and diphenhydramine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• disopyramide

  Minor (1)darifenacin will increase the level or effect of disopyramide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• docetaxel

  Minor (1)darifenacin will increase the level or effect of docetaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• donepezil

  Monitor Closely (1)donepezil increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (3)darifenacin will increase the level or effect of donepezil by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
  
  darifenacin will increase the level or effect of donepezil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  donepezil decreases effects of darifenacin by pharmacodynamic antagonism. Minor/Significance Unknown.

• donepezil transdermal

  Monitor Closely (1)donepezil transdermal, darifenacin. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor.

• dosulepin

  Monitor Closely (1)darifenacin and dosulepin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• doxepin

  Monitor Closely (2)darifenacin and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• dronedarone

  Monitor Closely (1)dronedarone will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)darifenacin will increase the level or effect of dronedarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• droperidol

  Monitor Closely (3)darifenacin decreases levels of droperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of droperidol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  droperidol increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• duloxetine

  Monitor Closely (1)darifenacin will increase the level or effect of duloxetine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• dutasteride

  Minor (1)darifenacin will increase the level or effect of dutasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• duvelisib

  Monitor Closely (1)duvelisib will increase the level or effect of darifenacin by affecting hepatic enzyme CYP2E1 metabolism. Modify Therapy/Monitor Closely. will increase the level or effect of

• echothiophate iodide

  Monitor Closely (1)echothiophate iodide increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• efavirenz

  Monitor Closely (1)efavirenz will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)darifenacin will increase the level or effect of efavirenz by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• elagolix

  Monitor Closely (1)elagolix will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.

• eletriptan

  Monitor Closely (1)darifenacin will increase the level or effect of eletriptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• eliglustat

  Contraindicated (1)darifenacin increases levels of eliglustat by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated. If coadministered with strong or moderate CYP2D6 inhibitors, reduce eliglustat dose from 84 mg BID to 84 mg once daily in extensive and intermediate metabolizers; eliglustat is contraindiated if strong or moderate CYP2D6 inhibitors are given concomitantly with strong or moderate CYP3A inhibitors.

• elvitegravir/cobicistat/emtricitabine/tenofovir DF

  Monitor Closely (1)elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.

• encainide

  Minor (1)darifenacin will increase the level or effect of encainide by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• encorafenib

  Monitor Closely (1)encorafenib, darifenacin. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.

• enzalutamide

  Monitor Closely (1)enzalutamide will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• eplerenone

  Minor (1)darifenacin will increase the level or effect of eplerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ergotamine

  Serious - Use Alternative (1)darifenacin will increase the level or effect of ergotamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erlotinib

  Monitor Closely (1)darifenacin will increase the level or effect of erlotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• erythromycin base

  Serious - Use Alternative (2)darifenacin will increase the level or effect of erythromycin base by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  erythromycin base will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin ethylsuccinate

  Serious - Use Alternative (2)erythromycin ethylsuccinate will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  darifenacin will increase the level or effect of erythromycin ethylsuccinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin lactobionate

  Serious - Use Alternative (2)erythromycin lactobionate will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  darifenacin will increase the level or effect of erythromycin lactobionate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• erythromycin stearate

  Serious - Use Alternative (2)erythromycin stearate will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
  
  darifenacin will increase the level or effect of erythromycin stearate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• eslicarbazepine acetate

  Monitor Closely (1)eslicarbazepine acetate will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• esomeprazole

  Minor (1)darifenacin will decrease the level or effect of esomeprazole by Other (see comment). Minor/Significance Unknown. Effectiveness of proton pump inhibitors may be decreased theoretically if administered with other antisecretory agents

• estradiol

  Monitor Closely (1)darifenacin will increase the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• estrogens conjugated synthetic

  Monitor Closely (1)darifenacin will increase the level or effect of estrogens conjugated synthetic by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• estrogens esterified

  Monitor Closely (1)darifenacin will increase the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• estropipate

  Monitor Closely (1)darifenacin will increase the level or effect of estropipate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• etonogestrel

  Monitor Closely (1)darifenacin will increase the level or effect of etonogestrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• etravirine

  Monitor Closely (2)darifenacin will increase the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  etravirine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• eucalyptus

  Minor (1)darifenacin will increase the level or effect of eucalyptus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• everolimus

  Serious - Use Alternative (1)darifenacin will increase the level or effect of everolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• fedratinib

  Monitor Closely (1)fedratinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.

• felodipine

  Monitor Closely (1)darifenacin will increase the level or effect of felodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fesoterodine

  Monitor Closely (2)darifenacin will increase the level or effect of fesoterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin and fesoterodine both decrease cholinergic effects/transmission. Use Caution/Monitor.Minor (1)darifenacin will increase the level or effect of fesoterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• fexinidazole

  Serious - Use Alternative (1)fexinidazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.

• finasteride

  Minor (1)darifenacin will increase the level or effect of finasteride by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• finerenone

  Monitor Closely (1)darifenacin will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or weak CYP3A4 inhibitors. Adjust finererone dosage as needed.

• flavoxate

  Monitor Closely (1)darifenacin and flavoxate both decrease cholinergic effects/transmission. Use Caution/Monitor.

• flecainide

  Monitor Closely (1)darifenacin will increase the level or effect of flecainide by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• flibanserin

  Monitor Closely (1)darifenacin will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors.

• fluconazole

  Monitor Closely (1)fluconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fludrocortisone

  Monitor Closely (1)darifenacin will increase the level or effect of fludrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fluoxetine

  Minor (1)darifenacin will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• fluphenazine

  Monitor Closely (3)darifenacin decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  fluphenazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of fluphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• fluvoxamine

  Monitor Closely (1)fluvoxamine will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosamprenavir

  Monitor Closely (2)darifenacin will increase the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  fosamprenavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosaprepitant

  Monitor Closely (2)fosaprepitant will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of fosaprepitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• fosphenytoin

  Monitor Closely (1)fosphenytoin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• galantamine

  Monitor Closely (1)galantamine increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (3)darifenacin will increase the level or effect of galantamine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
  
  darifenacin will increase the level or effect of galantamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
  
  galantamine decreases effects of darifenacin by pharmacodynamic antagonism. Minor/Significance Unknown.

• glycopyrrolate

  Monitor Closely (1)darifenacin and glycopyrrolate both decrease cholinergic effects/transmission. Use Caution/Monitor.

• glycopyrrolate inhaled

  Monitor Closely (1)darifenacin and glycopyrrolate inhaled both decrease cholinergic effects/transmission. Use Caution/Monitor.

• glycopyrronium tosylate topical

  Serious - Use Alternative (1)glycopyrronium tosylate topical, darifenacin. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration of glycopyrronium tosylate topical with other anticholinergic medications may result in additive anticholinergic adverse effects.

• grapefruit

  Monitor Closely (1)grapefruit will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• griseofulvin

  Monitor Closely (1)griseofulvin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• haloperidol

  Monitor Closely (4)darifenacin will increase the level or effect of haloperidol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor.
  
  haloperidol increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• henbane

  Monitor Closely (1)darifenacin and henbane both decrease cholinergic effects/transmission. Use Caution/Monitor.

• homatropine

  Monitor Closely (1)darifenacin and homatropine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• huperzine A

  Monitor Closely (1)huperzine A increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• hydrocodone

  Monitor Closely (1)darifenacin will increase the level or effect of hydrocodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone.

• hydrocortisone

  Monitor Closely (1)darifenacin will increase the level or effect of hydrocortisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• hydromorphone

  Monitor Closely (1)darifenacin will increase the level or effect of hydromorphone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• hydroxyprogesterone caproate

  Monitor Closely (1)darifenacin will increase the level or effect of hydroxyprogesterone caproate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• hyoscyamine

  Monitor Closely (1)darifenacin and hyoscyamine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• hyoscyamine spray

  Monitor Closely (1)darifenacin and hyoscyamine spray both decrease cholinergic effects/transmission. Use Caution/Monitor.

• idelalisib

  Serious - Use Alternative (1)idelalisib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates

• iloperidone

  Monitor Closely (6)darifenacin will increase the level or effect of iloperidone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of iloperidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin decreases levels of iloperidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of iloperidone by pharmacodynamic antagonism. Use Caution/Monitor.
  
  iloperidone increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  iloperidone increases levels of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.

• imatinib

  Minor (1)darifenacin will increase the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• imipramine

  Monitor Closely (3)darifenacin will increase the level or effect of imipramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of imipramine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin and imipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• indinavir

  Monitor Closely (1)darifenacin will increase the level or effect of indinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)indinavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• ipratropium

  Monitor Closely (1)darifenacin and ipratropium both decrease cholinergic effects/transmission. Use Caution/Monitor. Due to the poor systemic absorption of ipratropium, interaction unlikely at regularly recommended dosages.

• isavuconazonium sulfate

  Monitor Closely (1)darifenacin will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• isoniazid

  Monitor Closely (1)isoniazid will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• isradipine

  Minor (1)darifenacin will increase the level or effect of isradipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• istradefylline

  Monitor Closely (1)istradefylline will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.

• itraconazole

  Serious - Use Alternative (1)itraconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Not recommended during and 2 weeks after itraconazole.

• ivosidenib

  Serious - Use Alternative (1)ivosidenib will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternate therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.

• ixabepilone

  Monitor Closely (1)darifenacin will increase the level or effect of ixabepilone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ketoconazole

  Serious - Use Alternative (1)ketoconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.Minor (1)darifenacin will increase the level or effect of ketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• lansoprazole

  Minor (1)darifenacin decreases effects of lansoprazole by Other (see comment). Minor/Significance Unknown. Comment: Effectiveness of proton pump inhibitors may be decreased theoretically if administered with other antisecretory agents.

• lapatinib

  Monitor Closely (2)darifenacin will increase the level or effect of lapatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  lapatinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• larotrectinib

  Minor (1)larotrectinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• lemborexant

  Monitor Closely (1)darifenacin will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.

• lenacapavir

  Monitor Closely (1)lenacapavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lencapavir (a moderate CYP3A4 inhibitor) may increase CYP3A4 substrates initiated within 9 months after last SC dose of lenacapavir, which may increase potential risk of adverse reactions of CYP3A4 substrates.

• letermovir

  Monitor Closely (1)letermovir increases levels of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• levodopa

  Minor (1)darifenacin, levodopa. Other (see comment). Minor/Significance Unknown. Comment: Anticholinergic agents may enhance the therapeutic effects of levodopa; however, anticholinergic agents can exacerbate tardive dyskinesia. In high dosage, anticholinergics may decrease the effects of levodopa by delaying its GI absorption. .

• levoketoconazole

  Serious - Use Alternative (1)levoketoconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.Minor (1)darifenacin will increase the level or effect of levoketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• lofepramine

  Monitor Closely (2)darifenacin will increase the level or effect of lofepramine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin and lofepramine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• lomitapide

  Monitor Closely (1)darifenacin increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.

• lonafarnib

  Serious - Use Alternative (2)darifenacin will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of lonafarnib (a sensitive CYP3A substrate) with weak CYP3A inhibitors is unavoidable, reduce to, or continue lonafarnib at starting dose. Closely monitor for arrhythmias and events (eg, syncope, heart palpitations) since lonafarnib effect on QT interval is unknown.
  
  lonafarnib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.

• lopinavir

  Monitor Closely (1)darifenacin will increase the level or effect of lopinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)lopinavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• loratadine

  Monitor Closely (1)darifenacin will increase the level or effect of loratadine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)darifenacin will increase the level or effect of loratadine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• lorlatinib

  Monitor Closely (1)lorlatinib will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• lovastatin

  Serious - Use Alternative (1)darifenacin will increase the level or effect of lovastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• loxapine

  Monitor Closely (3)darifenacin decreases levels of loxapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of loxapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  loxapine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• loxapine inhaled

  Monitor Closely (2)loxapine inhaled increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  darifenacin decreases levels of loxapine inhaled by pharmacodynamic antagonism. Use Caution/Monitor.

• lumefantrine

  Monitor Closely (2)darifenacin will increase the level or effect of lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  lumefantrine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• maprotiline

  Monitor Closely (1)darifenacin and maprotiline both decrease cholinergic effects/transmission. Use Caution/Monitor.

• maraviroc

  Monitor Closely (1)darifenacin will increase the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• marijuana

  Monitor Closely (1)marijuana will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• meclizine

  Monitor Closely (1)darifenacin and meclizine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• mestranol

  Monitor Closely (1)darifenacin will increase the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• methadone

  Monitor Closely (1)darifenacin will increase the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• methamphetamine

  Monitor Closely (1)darifenacin will increase the level or effect of methamphetamine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• methscopolamine

  Monitor Closely (1)darifenacin and methscopolamine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• methylprednisolone

  Monitor Closely (1)darifenacin will increase the level or effect of methylprednisolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• metoprolol

  Monitor Closely (1)darifenacin will increase the level or effect of metoprolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• metronidazole

  Monitor Closely (1)metronidazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• mexiletine

  Monitor Closely (1)darifenacin will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• miconazole vaginal

  Monitor Closely (1)miconazole vaginal will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• midazolam

  Monitor Closely (1)darifenacin will increase the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• midazolam intranasal

  Monitor Closely (1)darifenacin will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.

• mifepristone

  Monitor Closely (1)mifepristone will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. In adults receiving mifepristone chronically for treatment of hormonal conditions, daily dose of darifenacin should not exceed 7.5 mg/day PO

• mitotane

  Monitor Closely (1)mitotane decreases levels of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.

• montelukast

  Minor (1)darifenacin will increase the level or effect of montelukast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• morphine

  Monitor Closely (1)darifenacin will increase the level or effect of morphine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• nafcillin

  Monitor Closely (1)nafcillin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inducers may increase metabolism of CYP3A4 substrates

• nebivolol

  Monitor Closely (1)darifenacin will increase the level or effect of nebivolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• nefazodone

  Serious - Use Alternative (1)nefazodone will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• nelfinavir

  Monitor Closely (2)darifenacin will increase the level or effect of nelfinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nelfinavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• neostigmine

  Monitor Closely (1)neostigmine increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• nevirapine

  Monitor Closely (1)nevirapine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• nicardipine

  Monitor Closely (1)darifenacin will increase the level or effect of nicardipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• nifedipine

  Monitor Closely (1)nifedipine will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)darifenacin will increase the level or effect of nifedipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nilotinib

  Monitor Closely (2)darifenacin will increase the level or effect of nilotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  nilotinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• nimodipine

  Minor (1)darifenacin will increase the level or effect of nimodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nisoldipine

  Monitor Closely (1)darifenacin will increase the level or effect of nisoldipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• nitrendipine

  Minor (1)darifenacin will increase the level or effect of nitrendipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• nortriptyline

  Monitor Closely (2)darifenacin will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  darifenacin and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.

• olanzapine

  Monitor Closely (3)darifenacin decreases levels of olanzapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of olanzapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  olanzapine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oliceridine

  Monitor Closely (2)darifenacin increases toxicity of oliceridine by Other (see comment). Use Caution/Monitor. Comment: Anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Monitor for signs of urinary retention or reduced gastric motility if oliceridine is coadministered with anticholinergics.
  
  darifenacin will increase the level or effect of oliceridine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. If concomitant use is necessary, may require less frequent oliceridine dosing. Closely monitor for respiratory depression and sedation and titrate subsequent doses accordingly. If inhibitor is discontinued, consider increase oliceridine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal.

• omeprazole

  Minor (1)darifenacin will decrease the level or effect of omeprazole by Other (see comment). Minor/Significance Unknown. Effectiveness of proton pump inhibitors may be decreased theoretically if administered with other antisecretory agents

• onabotulinumtoxinA

  Monitor Closely (1)onabotulinumtoxinA and darifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• orphenadrine

  Monitor Closely (1)darifenacin and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• oxcarbazepine

  Monitor Closely (1)oxcarbazepine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• oxybutynin

  Monitor Closely (1)darifenacin and oxybutynin both decrease cholinergic effects/transmission. Use Caution/Monitor.Minor (1)darifenacin will increase the level or effect of oxybutynin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• oxybutynin topical

  Monitor Closely (1)darifenacin and oxybutynin topical both decrease cholinergic effects/transmission. Use Caution/Monitor.

• oxybutynin transdermal

  Monitor Closely (1)darifenacin and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.

• oxycodone

  Monitor Closely (1)darifenacin will increase the level or effect of oxycodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• oxymorphone

  Monitor Closely (1)darifenacin will increase the level or effect of oxymorphone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• paclitaxel

  Minor (1)darifenacin will increase the level or effect of paclitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• paclitaxel protein bound

  Minor (1)darifenacin will increase the level or effect of paclitaxel protein bound by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• paliperidone

  Monitor Closely (3)darifenacin decreases levels of paliperidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of paliperidone by pharmacodynamic antagonism. Use Caution/Monitor.
  
  paliperidone increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• pancuronium

  Monitor Closely (1)darifenacin and pancuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• pantoprazole

  Minor (1)darifenacin decreases effects of pantoprazole by Other (see comment). Minor/Significance Unknown. Comment: Effectiveness of proton pump inhibitors may be decreased theoretically if administered with other antisecretory agents .

• parecoxib

  Minor (1)darifenacin will increase the level or effect of parecoxib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• paroxetine

  Minor (1)darifenacin will increase the level or effect of paroxetine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• pazopanib

  Serious - Use Alternative (1)darifenacin will increase the level or effect of pazopanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of pazopanib with strong CYP3A4 inhibitors if possible; if must coadminister, decrease pazopanib dose to 400 mg/day

• pentobarbital

  Monitor Closely (1)pentobarbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• perhexiline

  Minor (1)darifenacin will increase the level or effect of perhexiline by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• perphenazine

  Monitor Closely (3)darifenacin decreases levels of perphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of perphenazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  perphenazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of perphenazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• phenobarbital

  Monitor Closely (1)phenobarbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• phenytoin

  Monitor Closely (1)phenytoin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• physostigmine

  Monitor Closely (1)physostigmine increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• pilocarpine

  Monitor Closely (1)pilocarpine increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• pimozide

  Monitor Closely (3)darifenacin decreases levels of pimozide by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of pimozide by pharmacodynamic antagonism. Use Caution/Monitor.
  
  pimozide increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Serious - Use Alternative (1)darifenacin increases levels of pimozide by decreasing metabolism. Contraindicated. Risk of QT interval prolongation.Minor (1)darifenacin will increase the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• pioglitazone

  Minor (1)darifenacin will increase the level or effect of pioglitazone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• posaconazole

  Monitor Closely (1)posaconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• prabotulinumtoxinA

  Monitor Closely (1)darifenacin, prabotulinumtoxinA. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.

• pralidoxime

  Monitor Closely (1)darifenacin and pralidoxime both decrease cholinergic effects/transmission. Use Caution/Monitor.

• pramlintide

  Serious - Use Alternative (1)pramlintide, darifenacin. Either increases effects of the other by pharmacodynamic synergism. Contraindicated. Synergistic inhibition of GI motility.

• prednisone

  Monitor Closely (1)darifenacin will increase the level or effect of prednisone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• primidone

  Monitor Closely (1)primidone will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• prochlorperazine

  Monitor Closely (3)darifenacin decreases levels of prochlorperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of prochlorperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  prochlorperazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of prochlorperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• promazine

  Minor (1)darifenacin will increase the level or effect of promazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• promethazine

  Monitor Closely (3)darifenacin decreases levels of promethazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of promethazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  promethazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of promethazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• propafenone

  Monitor Closely (1)darifenacin will increase the level or effect of propafenone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Minor (1)darifenacin will increase the level or effect of propafenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• propantheline

  Monitor Closely (1)darifenacin and propantheline both decrease cholinergic effects/transmission. Use Caution/Monitor.

• propranolol

  Monitor Closely (1)darifenacin will increase the level or effect of propranolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• protriptyline

  Monitor Closely (1)darifenacin and protriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.

• pyridostigmine

  Monitor Closely (1)pyridostigmine increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• quetiapine

  Monitor Closely (4)darifenacin will increase the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin decreases levels of quetiapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of quetiapine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  quetiapine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• quinidine

  Monitor Closely (1)darifenacin will increase the level or effect of quinidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• quinine

  Minor (1)darifenacin will increase the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• quinupristin/dalfopristin

  Monitor Closely (1)quinupristin/dalfopristin will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rabeprazole

  Minor (1)darifenacin decreases effects of rabeprazole by Other (see comment). Minor/Significance Unknown. Comment: Effectiveness of proton pump inhibitors may be decreased theoretically if administered with other antisecretory agents.

• ramelteon

  Minor (1)darifenacin will increase the level or effect of ramelteon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ranolazine

  Serious - Use Alternative (1)darifenacin will increase the level or effect of ranolazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rapacuronium

  Monitor Closely (1)darifenacin and rapacuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• repaglinide

  Monitor Closely (1)darifenacin will increase the level or effect of repaglinide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• revefenacin

  Serious - Use Alternative (1)revefenacin and darifenacin both decrease cholinergic effects/transmission. Avoid or Use Alternate Drug. Coadministration may cause additive anticholinergic effects.

• ribociclib

  Serious - Use Alternative (1)ribociclib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rifabutin

  Serious - Use Alternative (1)rifabutin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rifampin

  Serious - Use Alternative (1)rifampin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• rifapentine

  Monitor Closely (1)rifapentine will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• risperidone

  Monitor Closely (3)darifenacin decreases levels of risperidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of risperidone by pharmacodynamic antagonism. Use Caution/Monitor.
  
  risperidone increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of risperidone by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• ritonavir

  Monitor Closely (2)darifenacin will increase the level or effect of ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  ritonavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• rivastigmine

  Monitor Closely (1)darifenacin decreases effects of rivastigmine by cholinergic effects/transmission. Use Caution/Monitor.

• rocuronium

  Monitor Closely (1)darifenacin and rocuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• rucaparib

  Monitor Closely (1)rucaparib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.

• rufinamide

  Monitor Closely (1)rufinamide will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• ruxolitinib

  Minor (1)darifenacin will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ruxolitinib topical

  Minor (1)darifenacin will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• saquinavir

  Monitor Closely (2)darifenacin will increase the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  saquinavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• saxagliptin

  Minor (1)darifenacin will increase the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• scopolamine

  Monitor Closely (1)darifenacin and scopolamine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• secobarbital

  Monitor Closely (1)secobarbital will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• secretin

  Serious - Use Alternative (1)darifenacin decreases effects of secretin by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Concomitant use of anticholinergic drugs may cause a hyporesponse to stimulation testing with secretin. Discontinue anticholinergic drugs at least 5 half-lives before administering secretin.

• silodosin

  Serious - Use Alternative (1)darifenacin will increase the level or effect of silodosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• simvastatin

  Serious - Use Alternative (1)darifenacin will increase the level or effect of simvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• sirolimus

  Serious - Use Alternative (1)darifenacin will increase the level or effect of sirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• solifenacin

  Monitor Closely (2)darifenacin will increase the level or effect of solifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin and solifenacin both decrease cholinergic effects/transmission. Use Caution/Monitor.

• St John's Wort

  Serious - Use Alternative (1)St John's Wort will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• stiripentol

  Monitor Closely (1)stiripentol, darifenacin. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.

• succinylcholine

  Monitor Closely (1)succinylcholine increases and darifenacin decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• sufentanil

  Minor (1)darifenacin will increase the level or effect of sufentanil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• sunitinib

  Monitor Closely (1)darifenacin will increase the level or effect of sunitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tacrolimus

  Monitor Closely (1)darifenacin will increase the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tamsulosin

  Monitor Closely (1)darifenacin increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• tazemetostat

  Monitor Closely (2)tazemetostat will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tecovirimat

  Monitor Closely (1)tecovirimat will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.

• temsirolimus

  Monitor Closely (1)darifenacin will increase the level or effect of temsirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• theophylline

  Monitor Closely (1)darifenacin will increase the level or effect of theophylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• thioridazine

  Monitor Closely (3)darifenacin decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  thioridazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Serious - Use Alternative (1)darifenacin will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

• thiothixene

  Monitor Closely (3)darifenacin decreases levels of thiothixene by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of thiothixene by pharmacodynamic antagonism. Use Caution/Monitor.
  
  thiothixene increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• timolol

  Monitor Closely (1)darifenacin will increase the level or effect of timolol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• tinidazole

  Monitor Closely (1)darifenacin will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tiotropium

  Monitor Closely (1)darifenacin and tiotropium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• tipranavir

  Monitor Closely (2)darifenacin will increase the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  tipranavir will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tolterodine

  Monitor Closely (2)darifenacin will increase the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  darifenacin and tolterodine both decrease cholinergic effects/transmission. Use Caution/Monitor.Minor (1)darifenacin will increase the level or effect of tolterodine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• tolvaptan

  Serious - Use Alternative (1)darifenacin will increase the level or effect of tolvaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

• topiramate

  Monitor Closely (1)topiramate will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• tramadol

  Minor (1)darifenacin will increase the level or effect of tramadol by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• trazodone

  Monitor Closely (1)darifenacin will increase the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.Minor (1)darifenacin and trazodone both decrease cholinergic effects/transmission. Minor/Significance Unknown.

• triamcinolone acetonide injectable suspension

  Monitor Closely (1)darifenacin will increase the level or effect of triamcinolone acetonide injectable suspension by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• triazolam

  Monitor Closely (1)darifenacin will increase the level or effect of triazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• trifluoperazine

  Monitor Closely (3)darifenacin decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• trihexyphenidyl

  Monitor Closely (1)darifenacin and trihexyphenidyl both decrease cholinergic effects/transmission. Use Caution/Monitor. Potential for additive anticholinergic effects.

• trimipramine

  Monitor Closely (1)darifenacin and trimipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.

• tropisetron

  Minor (1)darifenacin will increase the level or effect of tropisetron by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• trospium chloride

  Monitor Closely (1)darifenacin and trospium chloride both decrease cholinergic effects/transmission. Use Caution/Monitor.

• tucatinib

  Serious - Use Alternative (1)tucatinib will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.

• umeclidinium bromide/vilanterol inhaled

  Serious - Use Alternative (1)darifenacin, umeclidinium bromide/vilanterol inhaled. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Concomitant use with other anticholinergic-containing drugs may lead to additive anticholinergic adverse effects.

• vardenafil

  Monitor Closely (1)darifenacin will increase the level or effect of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• vecuronium

  Monitor Closely (1)darifenacin and vecuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.

• verapamil

  Monitor Closely (2)darifenacin will increase the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
  
  verapamil will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• vinblastine

  Minor (1)darifenacin will increase the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vincristine

  Minor (1)darifenacin will increase the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vincristine liposomal

  Minor (1)darifenacin will increase the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• vinorelbine

  Minor (1)darifenacin will increase the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• voriconazole

  Monitor Closely (1)voriconazole will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• voxelotor

  Serious - Use Alternative (1)voxelotor will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.

• zafirlukast

  Monitor Closely (1)zafirlukast will increase the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

• zaleplon

  Minor (1)darifenacin will increase the level or effect of zaleplon by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• ziprasidone

  Monitor Closely (3)darifenacin decreases levels of ziprasidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of ziprasidone by pharmacodynamic antagonism. Use Caution/Monitor.
  
  ziprasidone increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of ziprasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zolpidem

  Minor (1)darifenacin will increase the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zonisamide

  Minor (1)darifenacin will increase the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

• zotepine

  Monitor Closely (2)darifenacin decreases levels of zotepine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of zotepine by pharmacodynamic antagonism. Use Caution/Monitor.