- Last edited on April 15, 2024
Memantine
Primer
Memantine is used to treat moderate to severe Alzheimer's disease. It acts on the glutamatergic system by blocking NMDA receptors.
Indications
Mechanism of Action
- Glutamate is the main excitatory neurotransmitter in the brain, and binds to the NMDA receptor in the brain.
- Excessive glutamate release leads to excitotoxicity, which is thought to be a major mechanism of neurodegeneration in ischemia from stroke, trauma from traumatic brain injuries, and neurodegenerative disorders.
- However, glutamatergic transmission also important for long-term potentiation, and this is a proposed cellular model for learning and memory
- Memantine is a non-competitive NMDA receptor antagonist that is thought to help prevent excitotoxicity (mediated by Ca2+)
- Memantine blocks NMDA receptors and so may reduce the negative effects of glutamate, namely the excitotoxicity pathway via NMDA receptor over-activation, which is thought to prevent cell death.
- Memantine may also be neuroprotective.
Dosing
- Week 1: 5 mg PO qAM
- Week 2: 5 mg PO BID
- Week 3: 10 mg PO qAM and 5mg PO qHS
- Week 4: 10 mg PO BID
Renal
- Dose should be halved in patients with renal impairment.[2]
Contraindications
- Use with caution in patients with severe hepatic or renal impairment
Side Effects
- Memantine is generally well tolerated. Most common side effects may include insomnia, diarrhea, urinary incontinence, confusion, dizziness, or agitation.
- Memantine though not as effective, is much better tolerated than acetylcholinesterase inhibitors
Drug-Drug Interactions
- No major drug interactions.