How does oxybutynin interact with other medications and foods?

Oxybutynin may interact with some foods and drugs. As far as your diet goes, consuming grapefruit and grapefruit juice may complicate your use of oxybutynin. Ask your doctor for other possible dietary restrictions. Oxybutynin is known to interact with a number of medications, so make sure that your doctor is aware of any medications, herbal supplements or vitamins that you take. This will help minimize your risk of unforeseen drug interactions. The follow medications may have certain effects when used with oxybutynin:

May make both drugs less effective

• acetylcholinesterase inhibitor drugs
• donepezil (Aricept)
• galantamine (Razadyne)
• tacrine (Cognex)
• rivastigmine (Exelon)

May unsafely increase amounts of oxybutynin in bloodstream

• antifungal medications and antibiotics
• clarithromycin (Biaxin)
• isoniazid (Nydrazid)
• erythromycin (Ery-Tab)
• itraconazole (Sporanox)
• ketoconazole (Nizoral)
• protease inhibitors
• atazanavir (Reyataz)
• fosamprenavir (Lexiva)
• nelfinavir (Viracept)
• indinavir (Crixivan)
• ritonavir (Norvir)
• saquinavir (Invirase)

Increased risk of side effects

• anticholinergic medications
• atropine
• benztropine (Cogentin)
• belladonna (Donnatal, Bellamine S, B&O Supprettes)
• clidinium (Librax)
• clozapine (Clozaril)
• diphenhydramine (Benadryl, Tylenol PM)
• darifenacin (Enablex)
• dicyclomine (Bentyl)
• glycopyrrolate (Robinul)
• hyoscyamine (Levsin)
• haloperidol (Haldol)
• homatropine (Hycodan)
• ipratropium (Atrovent)
• scopolamine (Transderm Scop)
• trospium (Sanctura)
• tiotropium (Spiriva)
• pramlintide (Symlin)

Talk to your doctor before taking any of these drugs with oxybutyin. It is possible that these aren't all the possible drug interactions, so make sure that your doctor knows all of the medications you are taking.