Memantine and donepezil and Phenobarbital, hyoscyamine, atropine, and scopolamine interaction
Memantine and donepezil and Phenobarbital, hyoscyamine, atropine, and scopolamine: the Memantine and donepezil prescribing label describes an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Memantine and donepezil (Namzaric) label · effective 2026-03-06
Inducers of CYP3A4 (e.g., phenytoin, carbamazepine, dexamethasone, rifampin, and phenobarbital) could increase the rate of elimination of donepezil.
NAMZARIC may interfere with anticholinergic medications.
Use of Donepezil with Anticholinergics Because of their mechanism of action, cholinesterase inhibitors, including donepezil hydrochloride, have the potential to interfere with the activity of anticholinergic medications.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.