Marixino (Memantine Hydrochloride)

• Memantine Hydrochloride is an NMDA receptor antagonist indicated for the management of Alzheimer’s disease, a neurodegenerative disorder affecting memory and cognition.
• Alzheimer's disease (moderate to severe): improves cognition, global functioning and daily living activities.
• Alzheimer's disease (early to moderate): may be combined with cholinesterase inhibitors to support cognitive performance.
• Alzheimer's disease (behavioral symptoms): can help reduce agitation and aggression in some patients.

• Memantine Hydrochloride acts as a non‑competitive antagonist at the NMDA (N‑methyl‑D‑aspartate) receptor. By binding to the receptor-associated ion channel with moderate affinity, it blocks excessive calcium influx caused by overstimulation, thereby reducing excitotoxic neuronal injury while preserving normal synaptic transmission essential for learning and memory.

Memantine is generally well tolerated, but adverse reactions can occur. Common side effects are usually mild and transient, whereas serious or rare events require prompt medical attention.

Common Side Effects

• Dizziness
• Headache
• Constipation
• Nausea
• Fatigue
• Confusion

Serious or Rare Side Effects

• Seizures
• Severe allergic reactions (rash, swelling, anaphylaxis)
• Cardiac arrhythmias
• Hepatic injury
• Stevens‑Johnson syndrome or toxic epidermal necrolysis
• Psychosis or severe agitation

Memantine should be used with caution in specific clinical situations and patients should be monitored for potential risks.

• Renal impairment: dose adjustment may be required.
• History of seizures: monitor closely for increased seizure activity.
• Concurrent use of other NMDA antagonists: avoid additive neurotoxicity.
• Pregnancy: safety not established; use only if clearly needed.
• Elderly patients: watch for confusion, falls, or worsening cognition.
• Store at ambient temperature: keep in the original container, protect from moisture and direct sunlight.

Memantine may interact with several medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Amantadine: increased risk of neurotoxicity.
• Ketamine: additive NMDA antagonism may cause excessive CNS depression.
• Mannitol: may reduce oral absorption of memantine.

Moderate Interactions (Monitor Closely)

• Anticholinergic agents: may diminish cognitive benefits.
• CNS depressants (e.g., benzodiazepines): heightened sedation.
• Diuretics: potential electrolyte disturbances.
• Proton‑pump inhibitors: may modestly increase memantine plasma levels.
• Antihypertensives: monitor blood pressure for unexpected changes.