hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.thioridazineoxybutynin transdermal decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.oxybutynin transdermal decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.thioridazine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.thiothixeneoxybutynin transdermal decreases levels of thiothixene by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.oxybutynin transdermal decreases levels of thiothixene by pharmacodynamic antagonism. Use Caution/Monitor.thiothixene increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.tinidazoleoxybutynin transdermal will increase the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.tiotropiumoxybutynin transdermal and tiotropium both decrease cholinergic effects/transmission. Use Caution/Monitor.tolterodineoxybutynin transdermal and tolterodine both decrease cholinergic effects/transmission. Use Caution/Monitor.trazodoneoxybutynin transdermal and trazodone both decrease cholinergic effects/transmission. Use Caution/Monitor.trifluoperazineoxybutynin transdermal decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.oxybutynin transdermal decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.trifluoperazine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.trihexyphenidyloxybutynin transdermal and trihexyphenidyl both decrease cholinergic effects/transmission. Use Caution/Monitor. Potential for additive anticholinergic effects.trimipramineoxybutynin transdermal and trimipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.trospium chlorideoxybutynin transdermal and trospium chloride both decrease cholinergic effects/transmission. Use Caution/Monitor.vecuroniumoxybutynin transdermal and vecuronium both decrease cholinergic effects/transmission. Use Caution/Monitor.ziprasidoneoxybutynin transdermal decreases levels of ziprasidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.oxybutynin transdermal decreases levels of ziprasidone by pharmacodynamic antagonism. Use Caution/Monitor.ziprasidone increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.zotepineoxybutynin transdermal decreases levels of zotepine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.oxybutynin transdermal decreases levels of zotepine by pharmacodynamic antagonism. Use Caution/Monitor.Minor (21)acetaminophenoxybutynin transdermal decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.acetaminophen IVoxybutynin transdermal decreases levels of acetaminophen IV by unspecified interaction mechanism. Minor/Significance Unknown.acetaminophen rectaloxybutynin transdermal decreases levels of acetaminophen rectal by unspecified interaction mechanism. Minor/Significance Unknown.amantadineamantadine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Minor/Significance Unknown.atenololatenolol increases levels of oxybutynin transdermal by decreasing metabolism. Minor/Significance Unknown.chlorpromazineoxybutynin transdermal increases toxicity of chlorpromazine by unspecified interaction mechanism. Minor/Significance Unknown.digoxinoxybutynin transdermal increases levels of digoxin by unspecified interaction mechanism. Minor/Significance Unknown.dimenhydrinatedimenhydrinate increases toxicity of oxybutynin transdermal by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.donepezildonepezil decreases effects of oxybutynin transdermal by pharmacodynamic antagonism. Minor/Significance Unknown.fluphenazineoxybutynin transdermal increases toxicity of fluphenazine by unspecified interaction mechanism. Minor/Significance Unknown.galantaminegalantamine decreases effects of oxybutynin transdermal by pharmacodynamic antagonism. Minor/Significance Unknown.levodopaoxybutynin transdermal, levodopa. Other (see comment). Minor/Significance Unknown. Comment: Anticholinergic agents may enhance the therapeutic effects of levodopa; however, anticholinergic agents can exacerbate tardive dyskinesia. In high dosage, anticholinergics may decrease the effects of levodopa by delaying its GI absorption. .perphenazineoxybutynin transdermal increases toxicity of perphenazine by unspecified interaction mechanism. Minor/Significance Unknown.prochlorperazineoxybutynin transdermal increases toxicity of prochlorperazine by unspecified interaction mechanism. Minor/Significance Unknown.promazineoxybutynin transdermal increases toxicity of promazine by unspecified interaction mechanism. Minor/Significance Unknown.promethazineoxybutynin transdermal increases toxicity of promethazine by unspecified interaction mechanism. Minor/Significance Unknown.rimantadinerimantadine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Minor/Significance Unknown.ruxolitiniboxybutynin transdermal will increase the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.ruxolitinib topicaloxybutynin transdermal will increase the level or effect of ruxolitinib topical by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.thioridazineoxybutynin transdermal increases toxicity of thioridazine by unspecified interaction mechanism. Minor/Significance Unknown.trifluoperazineoxybutynin transdermal increases toxicity of trifluoperazine by unspecified interaction mechanism. Minor/Significance Unknown.abobotulinumtoxinAMonitor Closely (1)abobotulinumtoxinA increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.acetaminophenMinor (1)oxybutynin transdermal decreases levels of acetaminophen by unspecified interaction mechanism. Minor/Significance Unknown.acetaminophen IVMinor (1)oxybutynin transdermal decreases levels of acetaminophen IV by unspecified interaction mechanism. Minor/Significance Unknown.acetaminophen rectalMinor (1)oxybutynin transdermal decreases levels of acetaminophen rectal by unspecified interaction mechanism. Minor/Significance Unknown.aclidiniumMonitor Closely (1)oxybutynin transdermal and aclidinium both decrease cholinergic effects/transmission. Use Caution/Monitor.amantadineMonitor Closely (1)oxybutynin transdermal, amantadine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Potential for increased anticholinergic adverse effects.Minor (1)amantadine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Minor/Significance Unknown.amitriptylineMonitor Closely (1)oxybutynin transdermal and amitriptyline both decrease cholinergic effects/transmission. Use Caution/Monitor.amoxapineMonitor Closely (1)oxybutynin transdermal and amoxapine both decrease cholinergic effects/transmission. Use Caution/Monitor.anticholinergic/sedative combosMonitor Closely (1)anticholinergic/sedative combos and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.aripiprazoleMonitor Closely (3)oxybutynin transdermal decreases levels of aripiprazole by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin transdermal decreases levels of aripiprazole by pharmacodynamic antagonism. Use Caution/Monitor. aripiprazole increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.atenololMinor (1)atenolol increases levels of oxybutynin transdermal by decreasing metabolism. Minor/Significance Unknown.atracuriumMonitor Closely (1)atracurium and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.atropineMonitor Closely (1)atropine and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.atropine IV/IMMonitor Closely (1)atropine IV/IM and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.avapritinibMonitor Closely (1)oxybutynin transdermal will increase the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.axitinibMonitor Closely (1)oxybutynin transdermal increases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.belladonna alkaloidsMonitor Closely (1)belladonna alkaloids and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.belladonna and opiumMonitor Closely (1)belladonna and opium and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.benperidolMonitor Closely (3)oxybutynin transdermal decreases levels of benperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin transdermal decreases levels of benperidol by pharmacodynamic antagonism. Use Caution/Monitor. benperidol increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.benztropineMonitor Closely (1)benztropine and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor. Additive anticholinergic adverse effects may be seen with concurrent use. bethanecholMonitor Closely (1)bethanechol increases and oxybutynin transdermal decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.carbacholMonitor Closely (1)carbachol increases and oxybutynin transdermal decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.cevimelineMonitor Closely (1)cevimeline increases and oxybutynin transdermal decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.chlorpromazineMonitor Closely (3)oxybutynin transdermal decreases levels of chlorpromazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin transdermal decreases levels of chlorpromazine by pharmacodynamic antagonism. Use Caution/Monitor. chlorpromazine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)oxybutynin transdermal increases toxicity of chlorpromazine by unspecified interaction mechanism. Minor/Significance Unknown.cisatracuriumMonitor Closely (1)cisatracurium and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.clomipramineMonitor Closely (1)oxybutynin transdermal and clomipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.clozapineMonitor Closely (3)oxybutynin transdermal decreases levels of clozapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin transdermal decreases levels of clozapine by pharmacodynamic antagonism. Use Caution/Monitor. clozapine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.cyclizineMonitor Closely (1)cyclizine and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.cyclobenzaprineMonitor Closely (1)cyclobenzaprine and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.darifenacinMonitor Closely (1)darifenacin and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.desipramineMonitor Closely (1)oxybutynin transdermal and desipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.dicyclomineMonitor Closely (1)dicyclomine and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.digoxinMinor (1)oxybutynin transdermal increases levels of digoxin by unspecified interaction mechanism. Minor/Significance Unknown.dimenhydrinateMinor (1)dimenhydrinate increases toxicity of oxybutynin transdermal by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.diphenhydramineMonitor Closely (1)diphenhydramine and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.donepezilMonitor Closely (1)donepezil increases and oxybutynin transdermal decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)donepezil decreases effects of oxybutynin transdermal by pharmacodynamic antagonism. Minor/Significance Unknown.donepezil transdermalMonitor Closely (1)donepezil transdermal, oxybutynin transdermal. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor.dosulepinMonitor Closely (1)oxybutynin transdermal and dosulepin both decrease cholinergic effects/transmission. Use Caution/Monitor.doxepinMonitor Closely (1)oxybutynin transdermal and doxepin both decrease cholinergic effects/transmission. Use Caution/Monitor.droperidolMonitor Closely (3)oxybutynin transdermal decreases levels of droperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin transdermal decreases levels of droperidol by pharmacodynamic antagonism. Use Caution/Monitor. droperidol increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.echothiophate iodideMonitor Closely (1)echothiophate iodide increases and oxybutynin transdermal decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.fesoterodineMonitor Closely (1)fesoterodine and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.finerenoneMonitor Closely (1)oxybutynin transdermal 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.flavoxateMonitor Closely (1)flavoxate and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.flibanserinMonitor Closely (1)oxybutynin transdermal 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.fluphenazineMonitor Closely (3)oxybutynin transdermal decreases levels of fluphenazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin transdermal decreases levels of fluphenazine by pharmacodynamic antagonism. Use Caution/Monitor. fluphenazine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)oxybutynin transdermal increases toxicity of fluphenazine by unspecified interaction mechanism. Minor/Significance Unknown.galantamineMonitor Closely (1)galantamine increases and oxybutynin transdermal decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.Minor (1)galantamine decreases effects of oxybutynin transdermal by pharmacodynamic antagonism. Minor/Significance Unknown.glycopyrrolateMonitor Closely (1)glycopyrrolate and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.glycopyrrolate inhaledMonitor Closely (1)glycopyrrolate inhaled and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.haloperidolMonitor Closely (3)oxybutynin transdermal decreases levels of haloperidol by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin transdermal decreases effects of haloperidol by pharmacodynamic antagonism. Use Caution/Monitor. haloperidol increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.henbaneMonitor Closely (1)henbane and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.homatropineMonitor Closely (1)homatropine and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.huperzine AMonitor Closely (1)huperzine A increases and oxybutynin transdermal decreases cholinergic effects/transmission. Effect of interaction is not clear, use caution. Use Caution/Monitor.hyoscyamineMonitor Closely (1)hyoscyamine and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.hyoscyamine sprayMonitor Closely (1)hyoscyamine spray and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor.iloperidoneMonitor Closely (3)oxybutynin transdermal decreases levels of iloperidone by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin transdermal decreases levels of iloperidone by pharmacodynamic antagonism. Use Caution/Monitor. iloperidone increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.imipramineMonitor Closely (1)oxybutynin transdermal and imipramine both decrease cholinergic effects/transmission. Use Caution/Monitor.ipratropiumMonitor Closely (1)ipratropium and oxybutynin transdermal both decrease cholinergic effects/transmission. Use Caution/Monitor. Due to the poor systemic absorption of ipratropium, interaction unlikely at regularly recommended dosages.isavuconazonium sulfateMonitor Closely (1)oxybutynin transdermal will increase the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.ivacaftorMonitor Closely (1)oxybutynin transdermal increases levels of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Monitor when coadministered with weak CYP3A4 inhibitors .lemborexantMonitor Closely (1)oxybutynin transdermal 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.levodopaMonitor Closely (1)oxybutynin transdermal decreases effects of levodopa by pharmacodynamic antagonism. Use Caution/Monitor.Minor (1)oxybutynin transdermal, levodopa. Other (see comment). Minor/Significance Unknown. Comment: Anticholinergic agents may enhance the therapeutic effects of levodopa; however, anticholinergic agents can exacerbate tardive dyskinesia. In high dosage, anticholinergics may decrease the effects of levodopa by delaying its GI absorption. .lofepramineMonitor Closely (1)oxybutynin transdermal and lofepramine both decrease cholinergic effects/transmission. Use Caution/Monitor.lomitapideMonitor Closely (1)oxybutynin transdermal increases levels of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Lomitapide dose should not exceed 30 mg/day.lonafarnibSerious - Use Alternative (1)oxybutynin transdermal 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.loxapineMonitor Closely (3)oxybutynin transdermal decreases levels of loxapine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. oxybutynin transdermal decreases levels of loxapine by pharmacodynamic antagonism. Use Caution/Monitor. loxapine increases effects of oxybutynin transdermal