methenamine/hyoscyamine/methylene blue/phenyl salicylate/sodium phosphate monobasic (Rx)

Urinary Tract Irritative Voiding Symptoms

Symptoms resulting from urinary tract infection or diagnostic procedures: 1 tablet/capsule PO q6hr with liberal fluid intake

Urinary Tract Irritative Voiding Symptoms

≤6 years: Safety and efficacy not established

>6 years: Symptoms resulting from urinary tract infection or diagnostic procedures: 1 tablet/capsule PO q6hr with liberal fluid intake

Avoid except in short-term settings; high incidence of anticholinergic effects may occur (Beers criteria)

Contraindicated (5)

• cyproheptadine

  methylene blue, cyproheptadine. Other (see comment). Contraindicated. Comment: MAO inhibitors may prolong and intensify the anticholinergic effects of antihistamines. Cyproheptadine may diminish the serotonergic effect of MAO inhibitors.

• desvenlafaxine

  methylene blue and desvenlafaxine both increase serotonin levels. Contraindicated. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first

• deutetrabenazine

  methylene blue, deutetrabenazine. Either increases toxicity of the other by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Contraindicated. Deutetrabenazine should not be used in combination with an MAOI, or within 14 days of discontinuing therapy with an MAOI. If methylene blue must be used emergently, discontinue deutetrabenazine and monitor for adverse effects. Deutetrabenazine may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• fluoxetine

  methylene blue and fluoxetine both increase serotonin levels. Contraindicated. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue fluoxetine immediately and monitor for CNS toxicity. Fluoxetine may be resumed 24 hours after last methylene blue dose or after 5 weeks of monitoring, whichever comes first.

• vortioxetine

  methylene blue increases toxicity of vortioxetine by serotonin levels. Contraindicated. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be urgently administered, discontinue vortioxetine immediately and monitor for serotonin syndrome. Monitor for serotonin syndrome for 3 weeks or 24 hr after last methylene blue dose, whichever comes first. Vortioxetine may be resumed 24 hr after last methylene blue dose.

Serious - Use Alternative (93)

• 5-HTP

  methylene blue and 5-HTP both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last linezolid dose or after 2 weeks of monitoring, whichever comes first.

• acetazolamide

  acetazolamide, methenamine. Other (see comment). Contraindicated. Comment: This combination may form an insoluble precipitate in the urine, decreasing the effects of both agents.

• alfentanil

  methylene blue and alfentanil both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• almotriptan

  almotriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• amitriptyline

  methylene blue and amitriptyline both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• amoxapine

  amoxapine and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• belladonna alkaloids

  methylene blue and belladonna alkaloids both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• belladonna and opium

  methylene blue and belladonna and opium both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• benzhydrocodone/acetaminophen

  methylene blue increases toxicity of benzhydrocodone/acetaminophen by serotonin levels. Avoid or Use Alternate Drug. MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (eg, respiratory depression, coma). Opioids are not recommended for patients taking MAOIs or within 14 days of stopping MAOIs. If urgent opioid treatment needed, use test doses and frequent titration of small doses to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• buprenorphine

  methylene blue and buprenorphine both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• bupropion

  bupropion and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• buspirone

  methylene blue and buspirone both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• butalbital

  methylene blue and butalbital both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• butorphanol

  methylene blue and butorphanol both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• cholera vaccine

  methenamine, cholera vaccine. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Avoid coadministration of cholera vaccine with systemic antibiotics since these agents may be active against the vaccine strain. Do not administer cholera vaccine to patients who have received oral or parenteral antibiotics within 14 days prior to vaccination.

• citalopram

  methylene blue and citalopram both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• clomipramine

  methylene blue and clomipramine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• cocaine topical

  methylene blue and cocaine topical both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. Cocaine inhibits presynaptic reuptake of serotonin. Monitor for CNS toxicity.

• codeine

  methylene blue and codeine both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• cyclobenzaprine

  methylene blue and cyclobenzaprine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first

• desipramine

  methylene blue and desipramine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• dexfenfluramine

  methylene blue and dexfenfluramine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• dextroamphetamine

  methylene blue and dextroamphetamine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• dextromethorphan

  methylene blue and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• dihydroergotamine

  methylene blue and dihydroergotamine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• dihydroergotamine intranasal

  methylene blue and dihydroergotamine intranasal both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• doxepin

  methylene blue and doxepin both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• doxepin cream

  methylene blue and doxepin cream both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• doxylamine

  methylene blue and doxylamine both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• duloxetine

  methylene blue and duloxetine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• eletriptan

  eletriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• ergotamine

  methylene blue and ergotamine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• escitalopram

  methylene blue and escitalopram both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• fentanyl

  methylene blue and fentanyl both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• fluvoxamine

  fluvoxamine increases toxicity of methylene blue by serotonin levels. Avoid or Use Alternate Drug.

• frovatriptan

  frovatriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• glucagon

  glucagon increases toxicity of hyoscyamine by Other (see comment). Avoid or Use Alternate Drug. Comment: Coadministration of anticholinergic drugs and glucagon increase the risk of gastrointestinal adverse reactions due to additive effects on inhibition of gastrointestinal motility. .

• glucagon intranasal

  glucagon intranasal increases toxicity of hyoscyamine by Other (see comment). Avoid or Use Alternate Drug. Comment: Coadministration of anticholinergic drugs and glucagon increase the risk of gastrointestinal adverse reactions due to additive effects on inhibition of gastrointestinal motility. .

• glycopyrronium tosylate topical

  glycopyrronium tosylate topical, hyoscyamine. 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.

• hydrocodone

  methylene blue increases toxicity of hydrocodone by serotonin levels. Avoid or Use Alternate Drug. MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (eg, respiratory depression, coma). Opioids are not recommended for patients taking MAOIs or within 14 days of stopping MAOIs. If urgent opioid treatment needed, use test doses and frequent titration of small doses to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• hydromorphone

  methylene blue and hydromorphone both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• imipramine

  methylene blue and imipramine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• isocarboxazid

  methylene blue and isocarboxazid both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• isoniazid

  methylene blue and isoniazid both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue and isoniazid may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue isoniazid immediately and monitor for CNS toxicity. Isoniazid may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• L-tryptophan

  methylene blue and L-tryptophan both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• levodopa

  methylene blue and levodopa both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• levomilnacipran

  methylene blue and levomilnacipran both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• levorphanol

  methylene blue and levorphanol both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• linezolid

  methylene blue and linezolid both increase serotonin levels. Avoid or Use Alternate Drug. Both drugs increase serotonin as a result of MAO-A inhibition. Avoid coadministration if possible. If coadministered, monitor for CNS toxicity.

• lsd

  methylene blue and lsd both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity.

• maprotiline

  methylene blue and maprotiline both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• meperidine

  methylene blue and meperidine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• metformin

  methylene blue will increase the level or effect of metformin by unspecified interaction mechanism. Avoid or Use Alternate Drug.

• methadone

  methylene blue and methadone both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• microbiota oral

  methenamine decreases effects of microbiota oral by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Microbiota oral contains bacterial spores. Antibacterial agents may decrease efficacy if coadministered. Complete antibiotic regimens 2-4 days before initiating microbiota oral. .

• milnacipran

  methylene blue and milnacipran both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• mirtazapine

  methylene blue and mirtazapine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• morphine

  methylene blue and morphine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue morphine (if possible) and monitor for CNS toxicity. Morphine may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• naratriptan

  naratriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• nefazodone

  methylene blue and nefazodone both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• nortriptyline

  methylene blue and nortriptyline both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• oxycodone

  methylene blue and oxycodone both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• paroxetine

  methylene blue and paroxetine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• pentazocine

  methylene blue and pentazocine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue pentazocine (if possible) and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• phenelzine

  methylene blue and phenelzine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• pramlintide

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

• procarbazine

  methylene blue and procarbazine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• promethazine

  methylene blue and promethazine both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• protriptyline

  methylene blue and protriptyline both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• rasagiline

  methylene blue and rasagiline both increase serotonin levels. Avoid or Use Alternate Drug. Both methylene blue and rasagiline may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• remifentanil

  methylene blue and remifentanil both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• revefenacin

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

• rizatriptan

  rizatriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• safinamide

  methylene blue, safinamide. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug. Both methylene blue and safinamide may increase serotonin as a result of MAO-A inhibition. If IV methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• SAMe

  methylene blue and SAMe both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• secretin

  hyoscyamine 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.

• selegiline

  selegiline and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Both methylene blue and selegiline may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• selegiline transdermal

  selegiline transdermal and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Both methylene blue and selegiline may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• sertraline

  methylene blue and sertraline both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• St John's Wort

  methylene blue and St John's Wort both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• sufentanil SL

  methylene blue increases toxicity of sufentanil SL by serotonin levels. Avoid or Use Alternate Drug. MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (eg, respiratory depression, coma). Opioids are not recommended for patients taking MAOIs or within 14 days of stopping MAOIs. If urgent opioid treatment needed, use test doses and frequent titration of small doses to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• sulfadiazine

  methenamine, sulfadiazine. Other (see comment). Contraindicated. Comment: This combination may form an insoluble precipitate in the urine, decreasing the effects of both agents.

• sulfamethoxazole

  methenamine, sulfamethoxazole. Other (see comment). Contraindicated. Comment: This combination may form an insoluble precipitate in the urine, decreasing the effects of both agents.

• sulfisoxazole

  methenamine, sulfisoxazole. Other (see comment). Contraindicated. Comment: This combination may form an insoluble precipitate in the urine, decreasing the effects of both agents.

• sumatriptan

  sumatriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• sumatriptan intranasal

  sumatriptan intranasal and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• tedizolid

  tedizolid, methylene blue. Either increases effects of the other by Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. both increase levels of serotonin; increased risk of serotonin syndrome.

• tramadol

  methylene blue and tramadol both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• tranylcypromine

  methylene blue and tranylcypromine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• trazodone

  methylene blue and trazodone both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• trimipramine

  methylene blue and trimipramine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• umeclidinium bromide/vilanterol inhaled

  hyoscyamine, 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.

• valbenazine

  methylene blue, valbenazine. Other (see comment). Avoid or Use Alternate Drug. Comment: Coadministration of valbenazine with MAOIs may increase monoamine neurotransmitter concentration in synapses, potentially increasing risk of serotonin syndrome or attenuating valbenazine effect.

Monitor Closely (67)

• abobotulinumtoxinA

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

• aclidinium

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

• amantadine

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

• amitriptyline

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

• amoxapine

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

• anticholinergic/sedative combos

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

• aripiprazole

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

• artesunate

  methylene blue will increase the level or effect of artesunate by decreasing metabolism. Use Caution/Monitor. Coadministration may increase active artesunate metabolite (DHA) by inhibiting UGT. Monitor for increased adverse effects.

• atracurium

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

• atropine

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

• atropine IV/IM

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

• belladonna alkaloids

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

• belladonna and opium

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

• benperidol

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

• benztropine

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

• bethanechol

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

• buprenorphine subdermal implant

  methylene blue, buprenorphine subdermal implant. Either increases toxicity of the other by serotonin levels. Use Caution/Monitor. Concomitant use could result in life-threatening serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation, and during dose adjustment of the serotonergic drug. Discontinue buprenorphine if serotonin syndrome is suspected.

• buprenorphine, long-acting injection

  methylene blue, buprenorphine, long-acting injection. Either increases toxicity of the other by serotonin levels. Modify Therapy/Monitor Closely. Concomitant use could result in life-threatening serotonin syndrome or opioid toxicity (eg, respiratory depression, coma). Buprenorphine long-acting injection is not recommended for patients taking MAOIs or within 14 days of stopping such treatment.
  
  buprenorphine, long-acting injection increases effects of hyoscyamine by pharmacodynamic synergism. Use Caution/Monitor. Coadministration of buprenorphine with anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.

• carbachol

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

• lasmiditan

  methylene blue increases effects of lasmiditan by serotonin levels. Use Caution/Monitor. Coadministration may increase risk of serotonin syndrome.

• cevimeline

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

• chlorpromazine

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

• cisatracurium

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

• clomipramine

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

• clozapine

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

• cyclizine

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

• cyclobenzaprine

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

• darifenacin

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

• desipramine

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

• dicyclomine

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

• diphenhydramine

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

• donepezil

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

• donepezil transdermal

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

• dosulepin

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

• doxepin

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

• droperidol

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

• echothiophate iodide

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

• fesoterodine

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

• flavoxate

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

• fluphenazine

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

• galantamine

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

• glycopyrrolate

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

• glycopyrrolate inhaled

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

• haloperidol

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

• henbane

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

• homatropine

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

• huperzine A

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

• hydroxyzine

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

• iloperidone

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

• imipramine

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

• ipratropium

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

• levodopa

  hyoscyamine, levodopa. Other (see comment). Use Caution/Monitor. 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. .

• levodopa inhaled

  levodopa inhaled increases effects of methylene blue by dopaminergic effects. Use Caution/Monitor. Coadministration of selective MAO-B inhibitors with levodopa may be associated with orthostatic hypotension.

• lofepramine

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

• loxapine

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

• loxapine inhaled

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

• maprotiline

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

• meclizine

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

• methoxsalen

  methoxsalen, methylene blue. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive photosensitizing effects.

• methscopolamine

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

• metoclopramide intranasal

  hyoscyamine will decrease the level or effect of metoclopramide intranasal by Other (see comment). Use Caution/Monitor. Coadministration of metoclopramide intranasal with drugs that impair GI motility may decrease systemic absorption of metoclopramide. Monitor for reduced therapeutic effect.

• neostigmine

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

• nortriptyline

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

• olanzapine

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

• oliceridine

  hyoscyamine 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.
  
  methylene blue, oliceridine. Either increases effects of the other by serotonin levels. Modify Therapy/Monitor Closely.

• onabotulinumtoxinA

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

• tapentadol

  methylene blue and tapentadol both increase serotonin levels. Modify Therapy/Monitor Closely.

Minor (3)

• dimenhydrinate

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

• donepezil

  donepezil decreases effects of hyoscyamine by pharmacodynamic antagonism. Minor/Significance Unknown.

• galantamine

  galantamine decreases effects of hyoscyamine by pharmacodynamic antagonism. Minor/Significance Unknown.

• 5-HTP

  Serious - Use Alternative (1)methylene blue and 5-HTP both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last linezolid dose or after 2 weeks of monitoring, whichever comes first.

• abobotulinumtoxinA

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

• acetazolamide

  Serious - Use Alternative (1)acetazolamide, methenamine. Other (see comment). Contraindicated. Comment: This combination may form an insoluble precipitate in the urine, decreasing the effects of both agents.

• aclidinium

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

• alfentanil

  Serious - Use Alternative (1)methylene blue and alfentanil both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• almotriptan

  Serious - Use Alternative (1)almotriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• amantadine

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

• amitriptyline

  Monitor Closely (1)hyoscyamine and amitriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and amitriptyline both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• amoxapine

  Monitor Closely (1)hyoscyamine and amoxapine both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)amoxapine and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• anticholinergic/sedative combos

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

• aripiprazole

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

• artesunate

  Monitor Closely (1)methylene blue will increase the level or effect of artesunate by decreasing metabolism. Use Caution/Monitor. Coadministration may increase active artesunate metabolite (DHA) by inhibiting UGT. Monitor for increased adverse effects.

• atracurium

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

• atropine

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

• atropine IV/IM

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

• belladonna alkaloids

  Monitor Closely (1)belladonna alkaloids and hyoscyamine both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and belladonna alkaloids both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• belladonna and opium

  Monitor Closely (1)hyoscyamine and belladonna and opium both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and belladonna and opium both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• benperidol

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

• benzhydrocodone/acetaminophen

  Serious - Use Alternative (1)methylene blue increases toxicity of benzhydrocodone/acetaminophen by serotonin levels. Avoid or Use Alternate Drug. MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (eg, respiratory depression, coma). Opioids are not recommended for patients taking MAOIs or within 14 days of stopping MAOIs. If urgent opioid treatment needed, use test doses and frequent titration of small doses to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• benztropine

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

• buprenorphine

  Serious - Use Alternative (1)methylene blue and buprenorphine both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• buprenorphine subdermal implant

  Monitor Closely (1)methylene blue, buprenorphine subdermal implant. Either increases toxicity of the other by serotonin levels. Use Caution/Monitor. Concomitant use could result in life-threatening serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation, and during dose adjustment of the serotonergic drug. Discontinue buprenorphine if serotonin syndrome is suspected.

• buprenorphine, long-acting injection

  Monitor Closely (2)methylene blue, buprenorphine, long-acting injection. Either increases toxicity of the other by serotonin levels. Modify Therapy/Monitor Closely. Concomitant use could result in life-threatening serotonin syndrome or opioid toxicity (eg, respiratory depression, coma). Buprenorphine long-acting injection is not recommended for patients taking MAOIs or within 14 days of stopping such treatment.
  
  buprenorphine, long-acting injection increases effects of hyoscyamine by pharmacodynamic synergism. Use Caution/Monitor. Coadministration of buprenorphine with anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.

• bupropion

  Serious - Use Alternative (1)bupropion and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• buspirone

  Serious - Use Alternative (1)methylene blue and buspirone both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• butalbital

  Serious - Use Alternative (1)methylene blue and butalbital both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• butorphanol

  Serious - Use Alternative (1)methylene blue and butorphanol both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• carbachol

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

• cevimeline

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

• chlorpromazine

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

• cholera vaccine

  Serious - Use Alternative (1)methenamine, cholera vaccine. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Avoid coadministration of cholera vaccine with systemic antibiotics since these agents may be active against the vaccine strain. Do not administer cholera vaccine to patients who have received oral or parenteral antibiotics within 14 days prior to vaccination.

• cisatracurium

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

• citalopram

  Serious - Use Alternative (1)methylene blue and citalopram both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• clomipramine

  Monitor Closely (1)hyoscyamine and clomipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and clomipramine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• clozapine

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

• cocaine topical

  Serious - Use Alternative (1)methylene blue and cocaine topical both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. Cocaine inhibits presynaptic reuptake of serotonin. Monitor for CNS toxicity.

• codeine

  Serious - Use Alternative (1)methylene blue and codeine both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• cyclizine

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

• cyclobenzaprine

  Monitor Closely (1)cyclobenzaprine and hyoscyamine both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and cyclobenzaprine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first

• cyproheptadine

  Contraindicated (1)methylene blue, cyproheptadine. Other (see comment). Contraindicated. Comment: MAO inhibitors may prolong and intensify the anticholinergic effects of antihistamines. Cyproheptadine may diminish the serotonergic effect of MAO inhibitors.

• darifenacin

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

• desipramine

  Monitor Closely (1)hyoscyamine and desipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and desipramine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• desvenlafaxine

  Contraindicated (1)methylene blue and desvenlafaxine both increase serotonin levels. Contraindicated. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first

• deutetrabenazine

  Contraindicated (1)methylene blue, deutetrabenazine. Either increases toxicity of the other by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Contraindicated. Deutetrabenazine should not be used in combination with an MAOI, or within 14 days of discontinuing therapy with an MAOI. If methylene blue must be used emergently, discontinue deutetrabenazine and monitor for adverse effects. Deutetrabenazine may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• dexfenfluramine

  Serious - Use Alternative (1)methylene blue and dexfenfluramine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• dextroamphetamine

  Serious - Use Alternative (1)methylene blue and dextroamphetamine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• dextromethorphan

  Serious - Use Alternative (1)methylene blue and dextromethorphan both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• dicyclomine

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

• dihydroergotamine

  Serious - Use Alternative (1)methylene blue and dihydroergotamine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• dihydroergotamine intranasal

  Serious - Use Alternative (1)methylene blue and dihydroergotamine intranasal both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• dimenhydrinate

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

• diphenhydramine

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

• donepezil

  Monitor Closely (1)donepezil increases and hyoscyamine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)donepezil decreases effects of hyoscyamine by pharmacodynamic antagonism. Minor/Significance Unknown.

• donepezil transdermal

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

• dosulepin

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

• doxepin

  Monitor Closely (1)hyoscyamine and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and doxepin both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• doxepin cream

  Serious - Use Alternative (1)methylene blue and doxepin cream both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• doxylamine

  Serious - Use Alternative (1)methylene blue and doxylamine both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• droperidol

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

• duloxetine

  Serious - Use Alternative (1)methylene blue and duloxetine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• echothiophate iodide

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

• eletriptan

  Serious - Use Alternative (1)eletriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• ergotamine

  Serious - Use Alternative (1)methylene blue and ergotamine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• escitalopram

  Serious - Use Alternative (1)methylene blue and escitalopram both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• fentanyl

  Serious - Use Alternative (1)methylene blue and fentanyl both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• fesoterodine

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

• flavoxate

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

• fluoxetine

  Contraindicated (1)methylene blue and fluoxetine both increase serotonin levels. Contraindicated. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue fluoxetine immediately and monitor for CNS toxicity. Fluoxetine may be resumed 24 hours after last methylene blue dose or after 5 weeks of monitoring, whichever comes first.

• fluphenazine

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

• fluvoxamine

  Serious - Use Alternative (1)fluvoxamine increases toxicity of methylene blue by serotonin levels. Avoid or Use Alternate Drug.

• frovatriptan

  Serious - Use Alternative (1)frovatriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• galantamine

  Monitor Closely (1)galantamine increases and hyoscyamine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)galantamine decreases effects of hyoscyamine by pharmacodynamic antagonism. Minor/Significance Unknown.

• glucagon

  Serious - Use Alternative (1)glucagon increases toxicity of hyoscyamine by Other (see comment). Avoid or Use Alternate Drug. Comment: Coadministration of anticholinergic drugs and glucagon increase the risk of gastrointestinal adverse reactions due to additive effects on inhibition of gastrointestinal motility. .

• glucagon intranasal

  Serious - Use Alternative (1)glucagon intranasal increases toxicity of hyoscyamine by Other (see comment). Avoid or Use Alternate Drug. Comment: Coadministration of anticholinergic drugs and glucagon increase the risk of gastrointestinal adverse reactions due to additive effects on inhibition of gastrointestinal motility. .

• glycopyrrolate

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

• glycopyrrolate inhaled

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

• glycopyrronium tosylate topical

  Serious - Use Alternative (1)glycopyrronium tosylate topical, hyoscyamine. 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.

• haloperidol

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

• henbane

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

• homatropine

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

• huperzine A

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

• hydrocodone

  Serious - Use Alternative (1)methylene blue increases toxicity of hydrocodone by serotonin levels. Avoid or Use Alternate Drug. MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (eg, respiratory depression, coma). Opioids are not recommended for patients taking MAOIs or within 14 days of stopping MAOIs. If urgent opioid treatment needed, use test doses and frequent titration of small doses to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• hydromorphone

  Serious - Use Alternative (1)methylene blue and hydromorphone both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• hydroxyzine

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

• iloperidone

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

• imipramine

  Monitor Closely (1)hyoscyamine and imipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and imipramine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• ipratropium

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

• isocarboxazid

  Serious - Use Alternative (1)methylene blue and isocarboxazid both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• isoniazid

  Serious - Use Alternative (1)methylene blue and isoniazid both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue and isoniazid may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue isoniazid immediately and monitor for CNS toxicity. Isoniazid may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• L-tryptophan

  Serious - Use Alternative (1)methylene blue and L-tryptophan both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• lasmiditan

  Monitor Closely (1)methylene blue increases effects of lasmiditan by serotonin levels. Use Caution/Monitor. Coadministration may increase risk of serotonin syndrome.

• levodopa

  Monitor Closely (1)hyoscyamine, levodopa. Other (see comment). Use Caution/Monitor. 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. .Serious - Use Alternative (1)methylene blue and levodopa both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• levodopa inhaled

  Monitor Closely (1)levodopa inhaled increases effects of methylene blue by dopaminergic effects. Use Caution/Monitor. Coadministration of selective MAO-B inhibitors with levodopa may be associated with orthostatic hypotension.

• levomilnacipran

  Serious - Use Alternative (1)methylene blue and levomilnacipran both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• levorphanol

  Serious - Use Alternative (1)methylene blue and levorphanol both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• linezolid

  Serious - Use Alternative (1)methylene blue and linezolid both increase serotonin levels. Avoid or Use Alternate Drug. Both drugs increase serotonin as a result of MAO-A inhibition. Avoid coadministration if possible. If coadministered, monitor for CNS toxicity.

• lofepramine

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

• loxapine

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

• loxapine inhaled

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

• lsd

  Serious - Use Alternative (1)methylene blue and lsd both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity.

• maprotiline

  Monitor Closely (1)hyoscyamine and maprotiline both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and maprotiline both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• meclizine

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

• meperidine

  Serious - Use Alternative (1)methylene blue and meperidine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• metformin

  Serious - Use Alternative (1)methylene blue will increase the level or effect of metformin by unspecified interaction mechanism. Avoid or Use Alternate Drug.

• methadone

  Serious - Use Alternative (1)methylene blue and methadone both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• methoxsalen

  Monitor Closely (1)methoxsalen, methylene blue. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive photosensitizing effects.

• methscopolamine

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

• metoclopramide intranasal

  Monitor Closely (1)hyoscyamine will decrease the level or effect of metoclopramide intranasal by Other (see comment). Use Caution/Monitor. Coadministration of metoclopramide intranasal with drugs that impair GI motility may decrease systemic absorption of metoclopramide. Monitor for reduced therapeutic effect.

• microbiota oral

  Serious - Use Alternative (1)methenamine decreases effects of microbiota oral by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Microbiota oral contains bacterial spores. Antibacterial agents may decrease efficacy if coadministered. Complete antibiotic regimens 2-4 days before initiating microbiota oral. .

• milnacipran

  Serious - Use Alternative (1)methylene blue and milnacipran both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• mirtazapine

  Serious - Use Alternative (1)methylene blue and mirtazapine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• morphine

  Serious - Use Alternative (1)methylene blue and morphine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue morphine (if possible) and monitor for CNS toxicity. Morphine may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• naratriptan

  Serious - Use Alternative (1)naratriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• nefazodone

  Serious - Use Alternative (1)methylene blue and nefazodone both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• neostigmine

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

• nortriptyline

  Monitor Closely (1)hyoscyamine and nortriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and nortriptyline both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• olanzapine

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

• oliceridine

  Monitor Closely (2)hyoscyamine 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.
  
  methylene blue, oliceridine. Either increases effects of the other by serotonin levels. Modify Therapy/Monitor Closely.

• onabotulinumtoxinA

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

• orphenadrine

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

• oxybutynin

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

• oxybutynin topical

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

• oxybutynin transdermal

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

• oxycodone

  Serious - Use Alternative (1)methylene blue and oxycodone both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• paliperidone

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

• pancuronium

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

• paroxetine

  Serious - Use Alternative (1)methylene blue and paroxetine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• pentazocine

  Serious - Use Alternative (1)methylene blue and pentazocine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue pentazocine (if possible) and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• perphenazine

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

• phenelzine

  Serious - Use Alternative (1)methylene blue and phenelzine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• physostigmine

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

• pilocarpine

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

• pimozide

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

• prabotulinumtoxinA

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

• pramlintide

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

• procarbazine

  Serious - Use Alternative (1)methylene blue and procarbazine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• prochlorperazine

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

• promethazine

  Monitor Closely (3)hyoscyamine decreases levels of promethazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine decreases levels of promethazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  promethazine increases effects of hyoscyamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Serious - Use Alternative (1)methylene blue and promethazine both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• propantheline

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

• protriptyline

  Monitor Closely (1)hyoscyamine and protriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and protriptyline both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• pseudoephedrine

  Monitor Closely (1)methenamine decreases effects of pseudoephedrine by unknown mechanism. Use Caution/Monitor. Urinary excretion of indirect acting alpha/beta agonists (eg, pseudoephedrine) may increase when administered concomitantly with urinary acidifying agents, resulting in lower serum concentrations.

• pyridostigmine

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

• quetiapine

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

• rapacuronium

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

• rasagiline

  Serious - Use Alternative (1)methylene blue and rasagiline both increase serotonin levels. Avoid or Use Alternate Drug. Both methylene blue and rasagiline may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• remifentanil

  Serious - Use Alternative (1)methylene blue and remifentanil both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities

• revefenacin

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

• risperidone

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

• rizatriptan

  Serious - Use Alternative (1)rizatriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• rocuronium

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

• safinamide

  Serious - Use Alternative (1)methylene blue, safinamide. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug. Both methylene blue and safinamide may increase serotonin as a result of MAO-A inhibition. If IV methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• SAMe

  Serious - Use Alternative (1)methylene blue and SAMe both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• scopolamine

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

• secretin

  Serious - Use Alternative (1)hyoscyamine 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.

• selegiline

  Serious - Use Alternative (1)selegiline and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Both methylene blue and selegiline may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• selegiline transdermal

  Serious - Use Alternative (1)selegiline transdermal and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Both methylene blue and selegiline may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• sertraline

  Serious - Use Alternative (1)methylene blue and sertraline both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• sodium picosulfate/magnesium oxide/anhydrous citric acid

  Monitor Closely (1)methenamine decreases effects of sodium picosulfate/magnesium oxide/anhydrous citric acid by altering metabolism. Use Caution/Monitor. Coadministration with antibiotics decreases efficacy by altering colonic bacterial flora needed to convert sodium picosulfate to active drug.

• solifenacin

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

• St John's Wort

  Serious - Use Alternative (1)methylene blue and St John's Wort both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• succinylcholine

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

• sufentanil SL

  Serious - Use Alternative (1)methylene blue increases toxicity of sufentanil SL by serotonin levels. Avoid or Use Alternate Drug. MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (eg, respiratory depression, coma). Opioids are not recommended for patients taking MAOIs or within 14 days of stopping MAOIs. If urgent opioid treatment needed, use test doses and frequent titration of small doses to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• sulfadiazine

  Serious - Use Alternative (1)methenamine, sulfadiazine. Other (see comment). Contraindicated. Comment: This combination may form an insoluble precipitate in the urine, decreasing the effects of both agents.

• sulfamethoxazole

  Serious - Use Alternative (1)methenamine, sulfamethoxazole. Other (see comment). Contraindicated. Comment: This combination may form an insoluble precipitate in the urine, decreasing the effects of both agents.

• sulfisoxazole

  Serious - Use Alternative (1)methenamine, sulfisoxazole. Other (see comment). Contraindicated. Comment: This combination may form an insoluble precipitate in the urine, decreasing the effects of both agents.

• sumatriptan

  Serious - Use Alternative (1)sumatriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• sumatriptan intranasal

  Serious - Use Alternative (1)sumatriptan intranasal and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• tapentadol

  Monitor Closely (1)methylene blue and tapentadol both increase serotonin levels. Modify Therapy/Monitor Closely.

• tedizolid

  Serious - Use Alternative (1)tedizolid, methylene blue. Either increases effects of the other by Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. both increase levels of serotonin; increased risk of serotonin syndrome.

• thioridazine

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

• thiothixene

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

• tiotropium

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

• tolterodine

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

• tramadol

  Serious - Use Alternative (1)methylene blue and tramadol both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• tranylcypromine

  Serious - Use Alternative (1)methylene blue and tranylcypromine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• trazodone

  Monitor Closely (1)hyoscyamine and trazodone both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and trazodone both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• trifluoperazine

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

• trihexyphenidyl

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

• trimipramine

  Monitor Closely (1)hyoscyamine and trimipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.Serious - Use Alternative (1)methylene blue and trimipramine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• trospium chloride

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

• umeclidinium bromide

  Monitor Closely (1)umeclidinium bromide and hyoscyamine both decrease cholinergic effects/transmission. Use Caution/Monitor. If possible, avoid coadministration of additional anticholinergic agents

• umeclidinium bromide/vilanterol inhaled

  Serious - Use Alternative (1)hyoscyamine, 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.

• valbenazine

  Serious - Use Alternative (1)methylene blue, valbenazine. Other (see comment). Avoid or Use Alternate Drug. Comment: Coadministration of valbenazine with MAOIs may increase monoamine neurotransmitter concentration in synapses, potentially increasing risk of serotonin syndrome or attenuating valbenazine effect.

• vecuronium

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

• venlafaxine

  Serious - Use Alternative (1)methylene blue and venlafaxine both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• vilazodone

  Serious - Use Alternative (1)methylene blue and vilazodone both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• vortioxetine

  Contraindicated (1)methylene blue increases toxicity of vortioxetine by serotonin levels. Contraindicated. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be urgently administered, discontinue vortioxetine immediately and monitor for serotonin syndrome. Monitor for serotonin syndrome for 3 weeks or 24 hr after last methylene blue dose, whichever comes first. Vortioxetine may be resumed 24 hr after last methylene blue dose.

• ziprasidone

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

• zolmitriptan

  Serious - Use Alternative (1)zolmitriptan and methylene blue both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.

• zotepine

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