治療中重度及重度之阿茲海默症。

N-Methyl-D-Aspartate (NMDA) Receptor Antagonist

Absorption: well absorbed.
Distribution: 9 to 11 L/kg.
Protein binding: 45%.
Metabolism: Partially hepatic, primarily independent of the CYP enzyme system; forms 3 metabolites (minimal activity).
Half-life elimination: Terminal: ~60 to 80 hours.
Time to peak, serum: Immediate release: 3 to 7 hours; Extended release: 9 to 12 hours.
Excretion: Urine (74%).

Hypersensitivity to memantine or any component of the formulation.

B; Adverse events have been observed in animal reproduction studies.

1% to 10%:
Cardiovascular: Hypertension (4%).
Gastrointestinal: Abdominal pain (ER: 2%), constipation (3% to 5%), vomiting (2% to 3%).
Nervous system: confusion (6%), dizziness (5% to 7%), drowsiness (3%), fatigue (2%), hallucination (3%), headache (6%), pain (3%).
Neuromuscular & skeletal: Back pain (3%).
Respiratory: Cough (4%), dyspnea (2%).

1. Alzheimer disease, moderate to severe (monotherapy or in combination with a cholinesterase inhibitor):
Initial: 5 mg once daily; increase daily dose by 5 mg every week as tolerated to a target maximum dose of 20 mg/day. Dose may be administered once daily or in 2 divided doses.
2. Dementia (ie, Parkinson disease dementia, dementia with Lewy bodies, comorbid vascular dementia) (monotherapy or in combination with a cholinesterase inhibitor) (off-label use):
Initial: 5 mg once daily; increase dose by 5 mg every week as tolerated to a target maximum dose of 20 mg/day. Dose may be administered once daily or in 2 divided doses.
3. Neurocognitive toxicity of whole brain irradiation, prevention (off-label use):
5 mg once daily with the initiation of radiation; increase dose by 5 mg weekly as tolerated to a target maximum dose of 20 mg/day. Doses >5 mg/day may be given in 2 divided doses. Continue for up to 6 months after completion of whole brain radiation therapy (WBRT).

CrCl ≥50 mL/minute: No dosage adjustment necessary.
CrCl 30 to <50 mL/minute: Initial: 5 mg once daily; after at least 1 week of therapy and if tolerated, may increase in 5 mg increments no more frequently than weekly.
CrCl <30 mL/minute: Initial: 5 mg once daily; after at least 1 week of therapy and if tolerated, may increase to a target dose of 5 mg twice daily.

Mild-to-moderate impairment: No dosage adjustment necessary.