Nimotop (Nimodipine)

Nimotop is a calcium channel blocker used in the cerebrovascular field to prevent complications after subarachnoid haemorrhage.

• Subarachnoid haemorrhage: lowers the incidence of delayed cerebral vasospasm and associated ischemic injury.
• Cerebral vasospasm: improves cerebral blood flow by sustained vasodilation.
• Post‑haemorrhagic recovery: supports neurological outcomes by maintaining perfusion.

• Nimodipine selectively antagonises L‑type calcium channels in vascular smooth muscle, especially within cerebral arteries. By inhibiting calcium influx, it induces vasodilation of intracranial vessels, thereby increasing cerebral blood flow and reducing the likelihood of vasospasm after subarachnoid haemorrhage.

Nimotop is generally well tolerated, but several adverse reactions have been reported.

Common Side Effects

• Headache: mild to moderate intensity, often transient.
• Flushing: warm sensation with erythema, usually resolves without intervention.
• Dizziness or light‑headedness: related to blood pressure changes.
• Nausea: occasional gastrointestinal upset.
• Constipation: reduced bowel motility in some patients.

Serious or Rare Side Effects

• Severe hypotension: marked drop in blood pressure requiring medical attention.
• Cardiac arrhythmias: irregular heart rhythms, especially in patients with pre‑existing cardiac disease.
• Hepatic enzyme elevation: abnormal liver function tests.
• Allergic reactions: rash, pruritus, or anaphylaxis in rare cases.
• Thrombocytopenia: low platelet count observed in isolated reports.

Before initiating Nimotop, clinicians should consider several safety measures.

• Blood pressure monitoring: check for hypotension, especially after the first dose.
• Concomitant antihypertensives: adjust other blood‑pressure‑lowering drugs to avoid excessive drops.
• Hepatic impairment: use with caution; liver function may affect drug clearance.
• Renal impairment: dose adjustment may be required in severe renal dysfunction.
• Abrupt discontinuation: taper slowly to prevent rebound hypertension.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Nimotop can interact with several medicines that affect its metabolism or haemodynamic profile.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): may raise nimodipine plasma levels and increase toxicity.
• Potent antihypertensives (e.g., beta‑blockers, other calcium‑channel blockers): can cause severe hypotension.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampicin, carbamazepine): may reduce efficacy by lowering drug concentrations.
• Grapefruit juice: can modestly increase systemic exposure.
• Non‑steroidal anti‑inflammatory drugs (NSAIDs): may blunt the antihypertensive effect.
• Diuretics: may potentiate volume‑depletion‑related hypotension.