Mantomed (Memantine Hydrochloride)

Memantine is used in the management of Alzheimer’s disease, acting on the glutamatergic pathway to mitigate neurodegeneration.

• Alzheimer’s disease (moderate to severe): improves cognition and functional abilities.
• Alzheimer’s disease (mild to moderate) as adjunct to cholinesterase inhibitors: may provide additional benefit when combined therapy is needed.
• Behavioral disturbances in Alzheimer’s disease: may reduce agitation and aggression associated with the condition.

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

Memantine is generally well tolerated, but adverse reactions can occur.

Common Side Effects

• Dizziness: sensation of light‑headedness or unsteadiness.
• Headache: mild to moderate intensity.
• Constipation: reduced bowel movements.
• Confusion: transient disorientation.
• Fatigue: feeling unusually tired.
• Insomnia: difficulty falling or staying asleep.

Serious or Rare Side Effects

• Seizures: convulsive episodes requiring medical attention.
• Cardiac arrhythmia: irregular heart rhythm.
• Severe hypersensitivity: rash, swelling, or anaphylaxis.
• Hepatic dysfunction: elevated liver enzymes or jaundice.
• Stevens‑Johnson syndrome: severe skin reaction.
• Suicidal ideation: thoughts of self‑harm.

Memantine should be used with caution in specific clinical situations.

• Renal impairment: assess renal function and adjust therapy as needed.
• Hepatic impairment: monitor liver function tests regularly.
• History of seizures: observe for increased seizure activity.
• Concomitant NMDA agonists: avoid combined use to prevent antagonistic effects.
• Pregnancy: risk unknown; use only if potential benefit justifies potential risk.
• Store below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Memantine may interact with several medicines, requiring attention to avoid adverse outcomes.

Major Interactions (Avoid)

• Amantadine: additive NMDA antagonism may increase toxicity.
• Other NMDA antagonists: combined use can lead to excessive CNS depression.
• Strong CYP450 inhibitors (e.g., ketoconazole): may raise memantine plasma concentrations.

Moderate Interactions (Monitor Closely)

• Anticholinergic agents: may diminish therapeutic benefit.
• Diuretics: can heighten risk of dizziness or hypotension.
• Alcohol: may enhance central nervous system effects and increase sedation.