MEMANXA

What it is

MEMANXA is a film-coated tablet containing memantine hydrochloride, available in strengths of 5 mg, 10 mg, 15 mg or 20 mg.

Approved indications

— Treatment of the symptoms of moderately severe to severe Alzheimer's disease.

Dosing overview

The recommended maintenance dose is 20 mg per day, achieved by upward titration of 5 mg per week. Titration proceeds as follows: Week 1, 5 mg daily; Week 2, 10 mg daily; Week 3, 15 mg daily. MEMANXA should be administered once a day at the same time every day, taken with a little liquid, with or without food. In patients with mildly impaired renal function (creatinine clearance 50–80 mL/min), no dosage adjustment is required. In patients with moderate renal impairment (creatinine clearance 30–49 mL/min), the daily dose should be 10 mg per day.

Key safety warnings

MEMANXA is contraindicated in patients with epilepsy. Caution is recommended in patients with a former history of convulsions or patients with predisposing factors for epilepsy. In most clinical trials, patients with recent myocardial infarction, uncompensated congestive heart failure (NYHA III–IV), and uncontrolled hypertension were excluded. As a consequence, only limited data are available and patients with these conditions should be closely supervised. Animal studies have reported adverse effects of memantine on the visual system at high exposures. Specific ophthalmological examinations in a 6 month clinical study did not disclose any ocular changes in the double-blind placebo-controlled treatment period. At the end of an open label extension period, the incidence of cataract was reported in 11 out of 197 patients (6%) treated with memantine for 12 months compared to 5 out of 171 patients (3%) who received placebo in the double-blind period and then memantine for 6 months. Concomitant use of N-methyl-D-aspartate (NMDA) antagonists such as amantadine, ketamine or dextromethorphan should be avoided, as these compounds act at the same receptor system as memantine and may cause more frequent or more pronounced adverse drug reactions.

Contraindications

MEMANXA is contraindicated in patients with hypersensitivity to either the active ingredient or any of the excipients, and in patients with a current seizure disorder or with any history of seizures.

Regulatory history

MEMANXA memantine hydrochloride 10 mg tablets were first listed on the Australian Register of Therapeutic Goods on 17 November 2009.