Memantine Hydrochloride Zentiva Pharma Uk (Memantine Hydrochloride)

Memantine Hydrochloride is an NMDA receptor antagonist used in the management of Alzheimer’s disease.

• Moderate to severe Alzheimer’s disease: improves cognition and functional abilities.
• Mild Alzheimer’s disease: may provide modest benefit in memory and attention.
• Behavioral disturbances in Alzheimer’s disease: can help reduce agitation and aggression.

• Memantine Hydrochloride acts as a non‑competitive antagonist at the NMDA (N‑methyl‑D‑aspartate) receptor. By binding to the receptor-associated ion channel, it blocks excessive calcium influx caused by overstimulation with glutamate, thereby reducing excitotoxic neuronal damage and modulating synaptic transmission that underlies cognitive decline in Alzheimer’s disease.

Memantine Hydrochloride may cause a range of adverse reactions, most of which are mild and reversible.

Common Side Effects

• Dizziness: sensation of light‑headedness or unsteadiness.
• Headache: mild to moderate pain in the head region.
• Constipation: reduced bowel movements or hard stools.
• Confusion: transient difficulty concentrating or thinking clearly.
• Fatigue: feeling unusually tired or low in energy.
• Hypertension: mild increase in blood pressure.

Serious or Rare Side Effects

• Seizures: new‑onset convulsive episodes.
• Severe allergic reaction: rash, swelling, or difficulty breathing.
• Hallucinations: visual or auditory disturbances.
• Stevens‑Johnson syndrome: rare severe skin reaction.
• Suicidal thoughts: emergence of depressive ideation.
• Cardiac arrhythmias: irregular heart rhythm.

Before initiating therapy, clinicians should evaluate patient‑specific factors and monitor for potential complications.

• Renal impairment: assess kidney function and consider dose adjustment.
• History of seizures: monitor for increased seizure frequency.
• Cardiovascular disease: observe blood pressure and heart rate.
• Concurrent NMDA antagonists: avoid combined use to reduce CNS toxicity.
• Pregnancy and lactation: use only if clearly needed after risk‑benefit assessment.
• Store at ambient temperature: keep in the original container, protect from moisture and light.

Memantine may interact with other medicines that affect the central nervous system or its metabolism.

Major Interactions (Avoid)

• Amantadine: additive NMDA antagonism can increase neuro‑psychiatric adverse effects.
• Ketamine: combined NMDA blockade may cause profound CNS depression.
• Strong CYP450 inducers (e.g., carbamazepine): may lower memantine plasma concentrations.

Moderate Interactions (Monitor Closely)

• Anticholinergic agents: may worsen cognitive impairment.
• Diuretics: can enhance risk of hypotension.
• Alcohol: may increase dizziness and sedation.