The dosage of memantine hydrochloride shown to be effective in controlled clinical trials is 20 mg/day.
The recommended starting dose of memantine hydrochloride is 5 mg once daily. The recommended target dose is 20 mg/day. The dose should be increased in 5 mg increments to 10 mg/day (5 mg twice a day), 15 mg/day (5 mg and 10 mg as separate doses), and 20 mg/day (10 mg twice a day). The minimum recommended interval between dose increases is one week.
Memantine hydrochloride can be taken with or without food.
Doses in Special Populations
A target dose of 5 mg BID is recommended in patients with severe renal impairment (creatinine clearance of 5 to 29 mL/min based on the Cockroft-Gault equation):
For males: CLcr = [140-age (years)] · Weight (kg)/[72 · serum creatinine (mg/dL)]
For females: CLcr = 0.85 · [140-age (years)] · Weight (kg)/[72 · serum creatinine (mg/dL)]