Memantine
Brand: Namenda (US/EU) / Ebixa (EU) / Memantine (IN/BD)
Neurological
NMDA receptor antagonist (uncompetitive)
Pharmacokinetics
| Half-life | 70 hours |
| Tmax | 5 h |
| Bioavailability | 100 % (approx) |
| Protein Binding | 45 % |
| Volume of Distribution | 10 L/kg (approx) |
| Clearance Route | renal |
| Active Metabolites | no |
| Notes | Vd ~9–11 L/kg; largely excreted unchanged in urine; clearance decreases with alkaline urine—caution with alkalinizing agents (e.g., sodium bicarbonate, carbonic anhydrase inhibitors). |
⚠️ Safety & Warnings
Severity: Moderate
Adverse Effects:
Dizziness, headache, confusion, constipation, hypertension, somnolence
Contraindications:
Known hypersensitivity to memantine
Precautions:
Reduce dose in severe renal impairment; avoid/monitor with urine alkalinization (reduced clearance); caution with other NMDA antagonists; monitor neuropsychiatric status in dementia