Dosing & Uses
Dosage Forms & Strengths
injectable solution
- 30mg/mL
tablet, extended release
- 100mg
Muscle Spasm & Pain
Indicated for muscle spasm and relief of discomfort associated with acute painful musculoskeletal conditions
100 mg PO q12hr OR
60 mg IV/IM q12hr (switch to PO as soon as possible)
Other Indications & Uses
Off-label: Leg cramps resistant to quinine, Parkinson's disease
Safety and efficacy not established
Caution; not recommended for use in elderly because of increased sedation and anticholinergic effects
Muscle spasm, relief of discomfort associated with acute painful musculoskeletal conditions
100 mg PO q12hr OR
60 mg IV/IM q12hr (switch to PO as soon as possible)
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (1)
- fezolinetant
orphenadrine will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitors
Serious - Use Alternative (15)
- benzhydrocodone/acetaminophen
benzhydrocodone/acetaminophen, orphenadrine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
benzhydrocodone/acetaminophen and orphenadrine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate - buprenorphine subdermal implant
buprenorphine subdermal implant and orphenadrine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- buprenorphine transdermal
buprenorphine transdermal and orphenadrine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- buprenorphine, long-acting injection
buprenorphine, long-acting injection and orphenadrine both increase sedation. Avoid or Use Alternate Drug. Limit use to patients for whom alternative treatment options are inadequate
- calcium/magnesium/potassium/sodium oxybates
orphenadrine, calcium/magnesium/potassium/sodium oxybates. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- clonidine
clonidine, orphenadrine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Enhanced CNS depressant effects.
- fedratinib
orphenadrine will increase the level or effect of fedratinib by Other (see comment). Avoid or Use Alternate Drug. Avoid coadministration of fedratinib (a CYP3A4 and CYP2C19 substrate) with dual CYP3A4 and CYP2C19 inhibitor. Effect of coadministration of a dual CYP3A4 and CYP2C19 inhibitor with fedratinib has not been studied.
- glucagon
glucagon increases toxicity of orphenadrine 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 orphenadrine 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. .
- hydrocodone
hydrocodone, orphenadrine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- lonafarnib
orphenadrine will increase the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of lonafarnib (a sensitive CYP3A substrate) with weak CYP3A inhibitors is unavoidable, reduce to, or continue lonafarnib at starting dose. Closely monitor for arrhythmias and events (eg, syncope, heart palpitations) since lonafarnib effect on QT interval is unknown.
- metoclopramide intranasal
orphenadrine, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.
- olopatadine intranasal
orphenadrine and olopatadine intranasal both increase sedation. Avoid or Use Alternate Drug. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.
- sodium oxybate
orphenadrine, sodium oxybate. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- sufentanil SL
sufentanil SL, orphenadrine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
Monitor Closely (214)
- abobotulinumtoxinA
orphenadrine increases effects of abobotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Muscle relaxants may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.
abobotulinumtoxinA increases effects of orphenadrine by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects. - aclidinium
aclidinium and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- acrivastine
acrivastine and orphenadrine both increase sedation. Use Caution/Monitor.
- alfentanil
orphenadrine and alfentanil both increase sedation. Use Caution/Monitor.
- alprazolam
alprazolam and orphenadrine both increase sedation. Use Caution/Monitor.
- amisulpride
amisulpride and orphenadrine both increase sedation. Use Caution/Monitor.
- amitriptyline
amitriptyline and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and amitriptyline both increase sedation. Use Caution/Monitor. - amobarbital
amobarbital and orphenadrine both increase sedation. Use Caution/Monitor.
- amoxapine
amoxapine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and amoxapine both increase sedation. Use Caution/Monitor. - anticholinergic/sedative combos
anticholinergic/sedative combos and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- apomorphine
orphenadrine and apomorphine both increase sedation. Use Caution/Monitor.
- aripiprazole
orphenadrine and aripiprazole both increase sedation. Use Caution/Monitor.
- asenapine
asenapine and orphenadrine both increase sedation. Use Caution/Monitor.
- asenapine transdermal
asenapine transdermal and orphenadrine both increase sedation. Use Caution/Monitor.
- atracurium
atracurium and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- atropine
atropine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- atropine IV/IM
atropine IV/IM and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- avapritinib
orphenadrine will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
avapritinib and orphenadrine both increase sedation. Use Caution/Monitor. - axitinib
orphenadrine increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- azelastine
azelastine and orphenadrine both increase sedation. Use Caution/Monitor.
- baclofen
baclofen and orphenadrine both increase sedation. Use Caution/Monitor.
- belladonna alkaloids
belladonna alkaloids and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- belladonna and opium
belladonna and opium and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and belladonna and opium both increase sedation. Use Caution/Monitor. - benperidol
orphenadrine and benperidol both increase sedation. Use Caution/Monitor.
- benzphetamine
orphenadrine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- benztropine
benztropine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor. Additive anticholinergic adverse effects may be seen with concurrent use.
- bethanechol
bethanechol increases and orphenadrine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- brexanolone
brexanolone, orphenadrine. Either increases toxicity of the other by sedation. Use Caution/Monitor.
- brexpiprazole
brexpiprazole and orphenadrine both increase sedation. Use Caution/Monitor.
- brimonidine
brimonidine and orphenadrine both increase sedation. Use Caution/Monitor.
- brivaracetam
brivaracetam and orphenadrine both increase sedation. Use Caution/Monitor.
- brompheniramine
brompheniramine and orphenadrine both increase sedation. Use Caution/Monitor.
- buprenorphine
orphenadrine and buprenorphine both increase sedation. Use Caution/Monitor.
- buprenorphine buccal
orphenadrine and buprenorphine buccal both increase sedation. Use Caution/Monitor.
- buprenorphine, long-acting injection
buprenorphine, long-acting injection increases effects of orphenadrine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Buprenorphine may enhance the neuromuscular blocking action of skeletal muscle relaxants and increase risk for respiratory depression. Monitor for signs of respiratory depression that may be greater than otherwise expected and decrease muscle relaxant dosage as necessary.
- butabarbital
butabarbital and orphenadrine both increase sedation. Use Caution/Monitor.
- butalbital
butalbital and orphenadrine both increase sedation. Use Caution/Monitor.
- butorphanol
orphenadrine and butorphanol both increase sedation. Use Caution/Monitor.
- carbachol
carbachol increases and orphenadrine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- carbinoxamine
carbinoxamine and orphenadrine both increase sedation. Use Caution/Monitor.
- carisoprodol
carisoprodol and orphenadrine both increase sedation. Use Caution/Monitor.
- cevimeline
cevimeline increases and orphenadrine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- chloral hydrate
chloral hydrate and orphenadrine both increase sedation. Use Caution/Monitor.
- chlordiazepoxide
chlordiazepoxide and orphenadrine both increase sedation. Use Caution/Monitor.
- chlorpheniramine
chlorpheniramine and orphenadrine both increase sedation. Use Caution/Monitor.
- chlorpromazine
orphenadrine and chlorpromazine both increase sedation. Use Caution/Monitor.
- chlorzoxazone
chlorzoxazone and orphenadrine both increase sedation. Use Caution/Monitor.
- cinnarizine
cinnarizine and orphenadrine both increase sedation. Use Caution/Monitor.
- cisatracurium
cisatracurium and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- clemastine
clemastine and orphenadrine both increase sedation. Use Caution/Monitor.
- clomipramine
clomipramine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and clomipramine both increase sedation. Use Caution/Monitor. - clonazepam
clonazepam and orphenadrine both increase sedation. Use Caution/Monitor.
- clorazepate
clorazepate and orphenadrine both increase sedation. Use Caution/Monitor.
- clozapine
orphenadrine and clozapine both increase sedation. Use Caution/Monitor.
- codeine
orphenadrine and codeine both increase sedation. Use Caution/Monitor.
- cyclizine
cyclizine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
cyclizine and orphenadrine both increase sedation. Use Caution/Monitor. - cyclobenzaprine
cyclobenzaprine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
cyclobenzaprine and orphenadrine both increase sedation. Use Caution/Monitor. - cyproheptadine
cyproheptadine and orphenadrine both increase sedation. Use Caution/Monitor.
- dantrolene
dantrolene and orphenadrine both increase sedation. Use Caution/Monitor.
- daridorexant
orphenadrine and daridorexant both increase sedation. Modify Therapy/Monitor Closely. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.
- darifenacin
darifenacin and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- desipramine
desipramine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and desipramine both increase sedation. Use Caution/Monitor. - dexchlorpheniramine
dexchlorpheniramine and orphenadrine both increase sedation. Use Caution/Monitor.
- dexfenfluramine
orphenadrine increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dexmedetomidine
dexmedetomidine and orphenadrine both increase sedation. Use Caution/Monitor.
- dextromoramide
orphenadrine and dextromoramide both increase sedation. Use Caution/Monitor.
- diamorphine
orphenadrine and diamorphine both increase sedation. Use Caution/Monitor.
- diazepam
diazepam and orphenadrine both increase sedation. Use Caution/Monitor.
- dicyclomine
dicyclomine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- difelikefalin
difelikefalin and orphenadrine both increase sedation. Use Caution/Monitor.
- difenoxin hcl
orphenadrine and difenoxin hcl both increase sedation. Use Caution/Monitor.
- dimenhydrinate
dimenhydrinate and orphenadrine both increase sedation. Use Caution/Monitor.
- diphenhydramine
diphenhydramine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
diphenhydramine and orphenadrine both increase sedation. Use Caution/Monitor. - diphenoxylate hcl
orphenadrine and diphenoxylate hcl both increase sedation. Use Caution/Monitor.
- dipipanone
orphenadrine and dipipanone both increase sedation. Use Caution/Monitor.
- donepezil
donepezil increases and orphenadrine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dopexamine
orphenadrine increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dosulepin
orphenadrine and dosulepin both increase sedation. Use Caution/Monitor.
- doxepin
doxepin and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and doxepin both increase sedation. Use Caution/Monitor. - doxylamine
doxylamine and orphenadrine both increase sedation. Use Caution/Monitor.
- droperidol
orphenadrine and droperidol both increase sedation. Use Caution/Monitor.
- echothiophate iodide
echothiophate iodide increases and orphenadrine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- esketamine intranasal
esketamine intranasal, orphenadrine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.
- estazolam
estazolam and orphenadrine both increase sedation. Use Caution/Monitor.
- ethanol
orphenadrine and ethanol both increase sedation. Use Caution/Monitor.
- etomidate
etomidate and orphenadrine both increase sedation. Use Caution/Monitor.
- fenfluramine
orphenadrine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- fesoterodine
fesoterodine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- finerenone
orphenadrine will increase the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor serum potassium during initiation and dosage adjustment of either finererone or weak CYP3A4 inhibitors. Adjust finererone dosage as needed.
- flavoxate
flavoxate and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- flibanserin
orphenadrine will increase the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Increased flibanserin adverse effects may occur if coadministered with multiple weak CYP3A4 inhibitors.
- fluphenazine
orphenadrine and fluphenazine both increase sedation. Use Caution/Monitor.
- flurazepam
flurazepam and orphenadrine both increase sedation. Use Caution/Monitor.
- galantamine
galantamine increases and orphenadrine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ganaxolone
orphenadrine and ganaxolone both increase sedation. Use Caution/Monitor.
- glycopyrrolate
glycopyrrolate and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- glycopyrrolate inhaled
glycopyrrolate inhaled and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- haloperidol
orphenadrine and haloperidol both increase sedation. Use Caution/Monitor.
- homatropine
homatropine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- huperzine A
huperzine A increases and orphenadrine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- hydromorphone
orphenadrine and hydromorphone both increase sedation. Use Caution/Monitor.
- hydroxyzine
hydroxyzine and orphenadrine both increase sedation. Use Caution/Monitor.
- hyoscyamine
hyoscyamine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- hyoscyamine spray
hyoscyamine spray and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- iloperidone
orphenadrine and iloperidone both increase sedation. Use Caution/Monitor.
- imipramine
imipramine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and imipramine both increase sedation. Use Caution/Monitor. - incobotulinumtoxinA
orphenadrine, incobotulinumtoxinA. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Muscle relaxants may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.
- ipratropium
ipratropium and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- isavuconazonium sulfate
orphenadrine will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- ivacaftor
orphenadrine increases levels of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor when coadministered with weak CYP3A4 inhibitors .
- ketamine
ketamine and orphenadrine both increase sedation. Use Caution/Monitor.
- ketotifen, ophthalmic
orphenadrine and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.
- lemborexant
orphenadrine will increase the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Lower nightly dose of lemborexant recommended if coadministered with weak CYP3A4 inhibitors. See drug monograph for specific dosage modification.
- levorphanol
orphenadrine and levorphanol both increase sedation. Use Caution/Monitor.
- lofepramine
lofepramine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and lofepramine both increase sedation. Use Caution/Monitor. - lofexidine
orphenadrine and lofexidine both increase sedation. Use Caution/Monitor.
- lomitapide
orphenadrine increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.
- loprazolam
loprazolam and orphenadrine both increase sedation. Use Caution/Monitor.
- lorazepam
lorazepam and orphenadrine both increase sedation. Use Caution/Monitor.
- lormetazepam
lormetazepam and orphenadrine both increase sedation. Use Caution/Monitor.
- loxapine inhaled
orphenadrine and loxapine inhaled both increase sedation. Use Caution/Monitor.
- lurasidone
lurasidone, orphenadrine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity.
- maprotiline
maprotiline and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and maprotiline both increase sedation. Use Caution/Monitor. - marijuana
orphenadrine and marijuana both increase sedation. Use Caution/Monitor.
- mavacamten
orphenadrine will increase the level or effect of mavacamten by affecting hepatic enzyme CYP2C19 metabolism. Modify Therapy/Monitor Closely. Inititiation of weak CYP2C19 inhibitors may require decreased mavacamten dose.
- meclizine
meclizine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- melatonin
orphenadrine and melatonin both increase sedation. Use Caution/Monitor.
- meperidine
orphenadrine and meperidine both increase sedation. Use Caution/Monitor.
- meprobamate
orphenadrine and meprobamate both increase sedation. Use Caution/Monitor.
- metaxalone
metaxalone and orphenadrine both increase sedation. Use Caution/Monitor.
- methadone
orphenadrine and methadone both increase sedation. Use Caution/Monitor.
- methocarbamol
methocarbamol and orphenadrine both increase sedation. Use Caution/Monitor.
- methscopolamine
methscopolamine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- methylenedioxymethamphetamine
orphenadrine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- midazolam
midazolam and orphenadrine both increase sedation. Use Caution/Monitor.
- midazolam intranasal
orphenadrine will increase the level or effect of midazolam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of mild CYP3A4 inhibitors with midazolam intranasal may cause higher midazolam systemic exposure, which may prolong sedation.
midazolam intranasal, orphenadrine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect. - mirtazapine
orphenadrine and mirtazapine both increase sedation. Use Caution/Monitor.
- morphine
orphenadrine and morphine both increase sedation. Use Caution/Monitor.
- motherwort
orphenadrine and motherwort both increase sedation. Use Caution/Monitor.
- moxonidine
orphenadrine and moxonidine both increase sedation. Use Caution/Monitor.
- nabilone
orphenadrine and nabilone both increase sedation. Use Caution/Monitor.
- nalbuphine
orphenadrine and nalbuphine both increase sedation. Use Caution/Monitor.
- neostigmine
neostigmine increases and orphenadrine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- nortriptyline
nortriptyline and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and nortriptyline both increase sedation. Use Caution/Monitor. - olanzapine
orphenadrine and olanzapine both increase sedation. Use Caution/Monitor.
- oliceridine
oliceridine, orphenadrine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
orphenadrine increases toxicity of oliceridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Monitor for signs of urinary retention or reduced gastric motility if oliceridine is coadministered with anticholinergics. - onabotulinumtoxinA
onabotulinumtoxinA and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- opium tincture
orphenadrine and opium tincture both increase sedation. Use Caution/Monitor.
- oxazepam
oxazepam and orphenadrine both increase sedation. Use Caution/Monitor.
- oxybutynin
oxybutynin and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- oxybutynin topical
oxybutynin topical and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- oxybutynin transdermal
oxybutynin transdermal and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- oxycodone
orphenadrine and oxycodone both increase sedation. Use Caution/Monitor.
- oxymorphone
orphenadrine and oxymorphone both increase sedation. Use Caution/Monitor.
- paliperidone
orphenadrine and paliperidone both increase sedation. Use Caution/Monitor.
- pancuronium
pancuronium and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- papaveretum
orphenadrine and papaveretum both increase sedation. Use Caution/Monitor.
- papaverine
orphenadrine and papaverine both increase sedation. Use Caution/Monitor.
- pentazocine
orphenadrine and pentazocine both increase sedation. Use Caution/Monitor.
- pentobarbital
pentobarbital and orphenadrine both increase sedation. Use Caution/Monitor.
- perphenazine
orphenadrine and perphenazine both increase sedation. Use Caution/Monitor.
- phenobarbital
phenobarbital and orphenadrine both increase sedation. Use Caution/Monitor.
- phenylephrine PO
orphenadrine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .
- pholcodine
orphenadrine and pholcodine both increase sedation. Use Caution/Monitor.
- physostigmine
physostigmine increases and orphenadrine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- pilocarpine
pilocarpine increases and orphenadrine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- pimozide
orphenadrine and pimozide both increase sedation. Use Caution/Monitor.
- prabotulinumtoxinA
orphenadrine increases effects of prabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Muscle relaxants may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.
- pralidoxime
pralidoxime and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- primidone
primidone and orphenadrine both increase sedation. Use Caution/Monitor.
- prochlorperazine
orphenadrine and prochlorperazine both increase sedation. Use Caution/Monitor.
- promethazine
promethazine and orphenadrine both increase sedation. Use Caution/Monitor.
- propantheline
propantheline and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- propofol
propofol and orphenadrine both increase sedation. Use Caution/Monitor.
- propylhexedrine
orphenadrine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- protriptyline
protriptyline and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and protriptyline both increase sedation. Use Caution/Monitor. - pyridostigmine
pyridostigmine increases and orphenadrine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- quazepam
quazepam and orphenadrine both increase sedation. Use Caution/Monitor.
- quetiapine
orphenadrine and quetiapine both increase sedation. Use Caution/Monitor.
- ramelteon
orphenadrine and ramelteon both increase sedation. Use Caution/Monitor.
- rapacuronium
rapacuronium and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- remimazolam
remimazolam, orphenadrine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.
- risperidone
orphenadrine and risperidone both increase sedation. Use Caution/Monitor.
- rocuronium
rocuronium and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- scopolamine
scopolamine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- scullcap
orphenadrine and scullcap both increase sedation. Use Caution/Monitor.
- secobarbital
secobarbital and orphenadrine both increase sedation. Use Caution/Monitor.
- shepherd's purse
orphenadrine and shepherd's purse both increase sedation. Use Caution/Monitor.
- solifenacin
solifenacin and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- stiripentol
stiripentol, orphenadrine. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.
- succinylcholine
succinylcholine increases and orphenadrine decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- sufentanil
orphenadrine and sufentanil both increase sedation. Use Caution/Monitor.
- tapentadol
orphenadrine and tapentadol both increase sedation. Use Caution/Monitor.
- tazemetostat
orphenadrine will increase the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- temazepam
temazepam and orphenadrine both increase sedation. Use Caution/Monitor.
- thioridazine
orphenadrine and thioridazine both increase sedation. Use Caution/Monitor.
- thiothixene
orphenadrine and thiothixene both increase sedation. Use Caution/Monitor.
- tinidazole
orphenadrine will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tiotropium
tiotropium and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- tolterodine
tolterodine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- topiramate
orphenadrine and topiramate both increase sedation. Modify Therapy/Monitor Closely.
- tramadol
orphenadrine and tramadol both increase sedation. Use Caution/Monitor.
- trazodone
trazodone and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and trazodone both increase sedation. Use Caution/Monitor. - triazolam
triazolam and orphenadrine both increase sedation. Use Caution/Monitor.
- triclofos
triclofos and orphenadrine both increase sedation. Use Caution/Monitor.
- trifluoperazine
orphenadrine and trifluoperazine both increase sedation. Use Caution/Monitor.
- trihexyphenidyl
trihexyphenidyl and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor. Potential for additive anticholinergic effects.
- trimipramine
trimipramine and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
orphenadrine and trimipramine both increase sedation. Use Caution/Monitor. - trospium chloride
trospium chloride and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- vecuronium
vecuronium and orphenadrine both decrease cholinergic effects/transmission. Use Caution/Monitor.
- xylometazoline
orphenadrine increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ziconotide
orphenadrine and ziconotide both increase sedation. Use Caution/Monitor.
- ziprasidone
orphenadrine and ziprasidone both increase sedation. Use Caution/Monitor.
- zotepine
orphenadrine and zotepine both increase sedation. Use Caution/Monitor.
Minor (5)
- chlorpromazine
orphenadrine decreases levels of chlorpromazine by unknown mechanism. Minor/Significance Unknown. Excessive anticholinergic effects and/or hypoglycemia possible.
- eucalyptus
orphenadrine and eucalyptus both increase sedation. Minor/Significance Unknown.
- ruxolitinib
orphenadrine will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- ruxolitinib topical
orphenadrine will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- sage
orphenadrine and sage both increase sedation. Minor/Significance Unknown.
Adverse Effects
Frequency Not Defined
Dry mouth
Urinary retention
Blurred vision, mydriasis
Drowsiness
Headache
Weakness
Increased IOP
Palpitation
Tachycardia
GI disturbances
CNS stimulation (restlessness, agitation, insomnia, mental confusion)
Lightheadedness
Dizziness
Syncope
Pruritus
Urticarial rash
Tremor
Anaphylactic reactions
Aplastic anemia
Warnings
Contraindications
Hypersensitivity
Narrow-angle glaucoma
Pyloric/duodenal obstruction, BPH, stenosing peptic ulcers, cardiospasm (mega-esophagus), myasthenia gravis, obstructive uropathy, paralytic ileus, ulcerative colitis, toxic megacolon, achalasia
Cautions
Use caution in patients with diarrhea, partial obstructive uropathy, open-angle glaucoma, cardiovascular disease, hepatic/renal impairment, thyrotoxicosis, history of drug abuse or acute alcoholism
Some patients may experience transient episodes of light-headedness, dizziness or syncope; drug may impair ability of patient to engage in potentially hazardous activities such as operating machinery or driving a motor vehicle; ambulatory patients should be cautioned
May take with food to avoid stomach upset
Use with caution in patients with tachycardia, cardiac decompensation, coronary insufficiency, cardiac arrhythmias
Injectable form contains sulfites, & precipitates anaphylactic-type reactions in sensitive or asthmatic individuals
Safety of continuous long-term therapy not established; if orphenadrine is prescribed for prolonged use, periodic monitoring of blood, urine and liver function values is recommended
Drug interaction overview
- Confusion, anxiety and tremors have been reported in patients receiving propoxyphene and orphenadrine concomitantly; as symptoms may be simply due to an additive effect, reduction of dosage and/or discontinuation of one or both agents is recommended in such cases
Pregnancy & Lactation
Pregnancy Category: C
Lactation: no data
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
May work through central atropine-like effect; anticholinergic activity in brain stem; has euphorigenic and analgesic properties
Pharmacokinetics
Half-life elimination: 14-16 hr
Onset: 2-4 hr (peak)
Duration: 4-6 hr
Metabolism: Liver
Protein binding: 20%
Metabolites: Not fully determined (>8 metabolites)
Excretion: urine (principally)
Administration
IV/IM Administration
Administer IM or IV injection
IV may be given undiluted or diluted in SWI
Give slow IV ~5 min with pt in supine position
Patient should remain in this position for 5-10 min post-injection
To minimize adverse reactions after parenteral administration of the drug, patient should be assisted from recumbent position
Storage
Store at <40°C, preferably between 15-30°C
Protect from freezing
Protect from light; store in tight, light-resistant containers
Images
BRAND | FORM. | UNIT PRICE | PILL IMAGE |
---|---|---|---|
orphenadrine citrate oral - | 100 mg tablet | ![]() | |
orphenadrine citrate oral - | 100 mg tablet | ![]() | |
orphenadrine citrate oral - | 100 mg tablet | ![]() | |
orphenadrine citrate oral - | 100 mg tablet | ![]() | |
orphenadrine citrate oral - | 100 mg tablet | ![]() | |
orphenadrine citrate injection - | 30 mg/mL vial | ![]() | |
orphenadrine citrate injection - | 30 mg/mL vial | ![]() | |
orphenadrine citrate injection - | 30 mg/mL vial | ![]() |
Copyright © 2010 First DataBank, Inc.
Patient Handout
orphenadrine citrate oral
ORPHENADRINE - ORAL
(or-FEN-uh-dreen)
COMMON BRAND NAME(S): Norflex
USES: Orphenadrine is used to treat muscle spasms/pain. It is usually used along with rest, physical therapy, and other treatment.
HOW TO USE: Take this medication by mouth with or without food as directed by your doctor. Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.If you are using the extended-release tablets, swallow the tablets whole. Do not crush or chew the tablets. Doing so can release all of the drug at once, increasing the risk of side effects.Tell your doctor if your condition does not improve or if it worsens.
SIDE EFFECTS: Dry mouth, dizziness, drowsiness, lightheadedness, blurred vision, nausea, vomiting, and constipation may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.To relieve dry mouth, suck (sugarless) hard candy or ice chips, chew (sugarless) gum, drink water, or use a saliva substitute.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: mental/mood changes (such as confusion, anxiety, hallucinations), shaking (tremor), fast/pounding heartbeat, fainting, difficulty urinating, eye pain.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking orphenadrine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: high pressure in the eye (glaucoma), stomach/intestinal/esophagus problems (such as ulcers, blockage), difficulty urinating (such as due to enlarged prostate), a certain type of muscle/nerve disease (myasthenia gravis), heart problems (such as fast/irregular heartbeat, heart failure).This drug may make you dizzy or drowsy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Older adults may be more sensitive to the side effects of this drug, especially confusion, drowsiness, constipation, or trouble urinating. Confusion and drowsiness can increase the risk of falling.During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), other muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: unusual excitement, fast/irregular heartbeat, seizures.
NOTES: Do not share this medication with others.This medication has been prescribed for your current condition only. Do not use it later for another condition unless your doctor directs you to do so. A different medication may be necessary in that case.If you are taking this medication for a long time, lab and/or medical tests may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.
MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised December 2022. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
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