Nabila (Memantine)

• Memantine is used in the management of Alzheimer’s disease, targeting the glutamatergic pathway to improve cognitive function.
• Alzheimer’s disease (moderate to severe): improves cognition, memory and daily functioning in patients with advanced disease.
• Alzheimer’s disease (mild to moderate) as adjunct therapy: may provide additional benefit when combined with cholinesterase inhibitors.
• Behavioral symptoms of Alzheimer’s disease: can help reduce agitation and improve overall patient behavior.

• Memantine acts as a non‑competitive antagonist at the N‑methyl‑D‑aspartate (NMDA) receptor. By binding to the receptor‑associated ion channel, it blocks excessive calcium influx caused by prolonged glutamate activation, thereby reducing excitotoxic neuronal injury. This modulation of glutamatergic neurotransmission helps preserve neuronal function and slows the progression of cognitive decline in Alzheimer’s disease. The drug’s voltage‑dependent blocking properties allow normal synaptic activity while preventing pathological over‑stimulation.

Memantine may cause a range of adverse reactions, varying from mild to serious.

Common Side Effects

• Dizziness: sensation of light‑headedness or imbalance.
• Headache: mild to moderate pain in the head.
• Constipation: reduced bowel movements or hard stools.

Serious or Rare Side Effects

• Seizures: convulsive episodes requiring immediate medical attention.
• Severe allergic reaction: rash, swelling, or difficulty breathing.
• Hallucinations: visual or auditory disturbances.

When prescribing Memantine, clinicians should consider several precautionary measures to ensure patient safety.

• Renal impairment: dose adjustment may be required in patients with reduced kidney function.
• Hepatic disease: monitor liver function as metabolism may be affected.
• Concomitant use with NMDA antagonists: avoid additive neuro‑psychiatric effects.
• History of seizures: use with caution and monitor for seizure activity.
• Psychiatric disorders: assess for worsening depression or psychosis.
• Store at ambient temperature: keep in original packaging, protect from moisture and heat.

Memantine can interact with other medicines, influencing its efficacy or safety profile.

Major Interactions (Avoid)

• Amantadine: combined NMDA antagonism may increase neuro‑psychiatric side effects.
• Ketamine: additive NMDA blockade can lead to excessive sedation or cognitive impairment.

Moderate Interactions (Monitor Closely)

• Anticholinesterase inhibitors (e.g., donepezil): monitor for altered cognitive response.
• Diuretics (e.g., furosemide): may increase risk of renal dysfunction.
• CNS depressants (e.g., benzodiazepines): may enhance sedation.
• Anticonvulsants (e.g., carbamazepine): may affect memantine plasma levels.