Medication Pearl of the Day: Memantine and Donepezil (Namzaric)
Indication: Namzaric is a combination of memantine hydrochloride extended release, a NMDA receptor antagonist, and donepezil hydrochloride, an acetylcholinesterase inhibitor, indicated for the treatment of moderate to severe dementia related to Alzheimer disease.
- Dosing: Patients on memantine hydrochloride (10 mg twice daily or 28 mg extended release once daily) and donepezil hydrochloride 10 mg can be switched to Namzaric 28 mg/10 mg, taken once a day in the evening.
- Dosage forms: 14 mg memantine hydrochloride extended-release and 10 mg donepezil hydrochloride; 28 mg memantine hydrochloride extended-release and 10 mg donepezil hydrochloride.
- Adverse events: The most common adverse reactions occurring at a frequency of at least 5% and greater than placebo with memantine hydrochloride extended-release 28 mg/day were headache, diarrhea, and dizziness.
- Mechanism of action: Memantine is postulated to exert its therapeutic effect through its action as a low to moderate affinity uncompetitive (open channel) NMDA receptor antagonist that binds preferentially to the NMDA receptor-operated cation channels. Donepezil is postulated to exert its therapeutic effect by enhancing cholinergic function. This is accomplished by increasing the concentration of acetylcholine in the central nervous system through reversible inhibition of its hydrolysis by acetylcholinesterase.
NAMZARIC (memantine hydrochloride extended-release and donepezil) (fda.gov)