Nimotop (nimodipine) is a calcium channel blocker specifically formulated for the improvement of neurological outcome by reducing the incidence and severity of ischemic deficits in patients with subarachnoid hemorrhage (SAH) from ruptured congenital intracranial aneurysms, irrespective of their post-ictus neurological condition. Its primary mechanism of action is the selective relaxation of vascular smooth muscle in cerebral arteries, mitigating the profound vasoconstriction that often leads to delayed cerebral ischemia, a major cause of morbidity and mortality following SAH. This targeted cerebroselectivity distinguishes it from other calcium antagonists, making it a cornerstone of prophylactic neurovascular management in eligible patient populations. Administration typically commences within 96 hours of the hemorrhage and continues for a 21-day course, aligning with the highest risk period for vasospasm.

Features

• Active Ingredient: Nimodipine (30 mg per soft gelatin capsule).
• Pharmacologic Class: Dihydropyridine calcium channel blocker.
• Formulation: Oral soft gelatin capsules or liquid-filled capsules for nasogastric tube administration.
• Primary Indication: To improve neurological outcome by reducing the incidence and severity of ischemic deficits in patients with subarachnoid hemorrhage from ruptured congenital intracranial aneurysms who are in good neurological condition post-ictus (e.g., Hunt and Hess Grades I-III).
• Mechanism: Selective inhibition of calcium ion influx across L-type channels in cerebrovascular smooth muscle, leading to vasodilation.
• Bioavailability: Approximately 13% following oral administration due to significant first-pass metabolism.
• Half-life: Terminal elimination half-life is 8-9 hours.
• Metabolism: Extensively metabolized via the cytochrome P450 system (primarily CYP3A4).
• Excretion: Approximately 50% excreted in urine as metabolites, and 32% in feces.

Benefits

• Reduces Risk of Cerebral Ischemia: Prophylactic administration significantly lowers the incidence of cerebral infarctions resulting from vasospasm.
• Improves Neurological Outcomes: Clinically proven to lead to better overall neurological recovery and functional status at follow-up assessments.
• Cerebroselective Action: Exerts a preferential effect on cerebral arteries over systemic vasculature at recommended doses, focusing therapy where it is most needed.
• Standard of Care: Represents an evidence-based, guideline-recommended pharmacological intervention in the management of aneurysmal SAH.
• Multiple Administration Routes: The liquid-filled capsule formulation allows for reliable dosing in intubated or dysphagic patients via nasogastric tube.

Common use

Nimotop is exclusively indicated for the improvement of neurological outcome by reducing the incidence and severity of ischemic deficits in patients with subarachnoid hemorrhage (SAH) from ruptured congenital intracranial aneurysms. Its use is most established in patients who are in good neurological condition post-ictus, such as those classified as Hunt and Hess Grades I-III. Treatment is prophylactic and should be initiated as soon as possible following the diagnosis of aneurysmal SAH, ideally within 96 hours of the onset of bleeding. It is not indicated for the treatment of high blood pressure outside of this specific neurovascular context. Its application is a standard component of post-operative or post-coiling management to prevent delayed cerebral ischemia, a serious and common complication of SAH.

Dosage and direction

The standard dosage for oral administration is 60 mg (two 30 mg capsules) every 4 hours for 21 consecutive days.

For patients who are unable to swallow the capsules (e.g., intubated, with a depressed gag reflex), the liquid contents of the capsules can be extracted for administration via a nasogastric tube. Using an 18-gauge needle, puncture the capsule and withdraw the contents into a syringe. The contents should then be emptied into the nasogastric tube funnel and flushed through with 30 mL of normal saline (0.9%).

Treatment should be initiated within 96 hours of the onset of subarachnoid hemorrhage. It is critical to adhere to the strict 4-hour dosing schedule to maintain consistent therapeutic plasma levels. If the capsule is taken on an empty stomach, consistency is important; however, taking it with food may help minimize potential gastrointestinal side effects. Do not administer intravenously or by any parenteral route—the formulation is for oral/nasogastric use only.

Precautions

• Hypotension: Nimotop can cause hypotension, which may be more pronounced in patients with pre-existing low blood pressure or those who are volume-depleted. Blood pressure should be monitored regularly, especially during the initiation of therapy.
• Liver Impairment: Nimodipine is extensively metabolized by the liver. Patients with impaired hepatic function (e.g., cirrhosis) may have significantly increased bioavailability and decreased clearance, leading to elevated plasma levels and an increased risk of adverse effects. Dose reduction may be necessary.
• CYP3A4 Inhibitors: Concomitant use with strong inhibitors of the CYP3A4 enzyme system can drastically increase nimodipine plasma concentrations,potentiating its effects and side effects. This combination should be avoided.
• Grapefruit Juice: Patients should avoid grapefruit juice during treatment, as it inhibits CYP3A4 metabolism and can increase nimodipine bioavailability.
• Pregnancy and Lactation: Nimotop should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is not known whether nimodipine is excreted in human milk; a decision should be made whether to discontinue nursing or discontinue the drug.
• Pediatric Use: Safety and effectiveness in pediatric patients have not been established.
• Geriatric Use: Elderly patients may exhibit increased bioavailability and a higher incidence of side effects, particularly hypotension. Caution is advised.

Contraindications

Nimotop is contraindicated in patients with a known hypersensitivity to nimodipine, any other calcium channel blocker, or any component of the capsule formulation. Its concomitant use with strong CYP3A4 inhibitors in the plasma concentration range that leads to interactions is also contraindicated. This includes drugs such as ketoconazole, itraconazole, clarithromycin, ritonavir, and nefazodone.

Possible side effect

The most common side effects are related to its pharmacological effect of vasodilation, particularly a decrease in blood pressure.

• Common (>1%): Decreased blood pressure, headache, nausea.
• Less Common (0.1% - 1%): Edema (swelling), diarrhea, rash, vomiting, bradycardia (slow heart rate), tachycardia (fast heart rate), flushing, dizziness.
• Rare (<0.1%): Gastrointestinal hemorrhage, thrombocytopenia, leukopenia, elevated liver enzymes (ALT, AST), depression, drowsiness.
• Serious: Profound hypotension requiring intervention, ileus (intestinal obstruction), hepatitis. If signs of a severe allergic reaction (e.g., anaphylaxis, Stevens-Johnson syndrome) occur, discontinue immediately and initiate appropriate treatment.

Drug interaction

Nimodipine is a substrate of the CYP3A4 enzyme system. Interactions are primarily pharmacokinetic.

• Strong CYP3A4 Inhibitors (CONTRAINDICATED): Ketoconazole, itraconazole, clarithromycin, ritonavir, nefazodone. Concomitant use can increase nimodipine AUC by up to 8-fold, drastically increasing the risk of severe hypotension and other adverse effects.
• Moderate/Weak CYP3A4 Inhibitors: Diltiazem, verapamil, erythromycin, fluconazole, amiodarone. Use with caution and monitor for increased effects of nimodipine (hypotension, headache). A dose reduction of Nimotop may be required.
• CYP3A4 Inducers: Rifampin, carbamazepine, phenytoin, St. John’s Wort. These drugs may increase the metabolism of nimodipine, potentially reducing its plasma concentration and therapeutic efficacy.
• Other Antihypertensives: Beta-blockers, ACE inhibitors, other calcium channel blockers, diuretics. Concomitant use may potentiate the hypotensive effects of nimodipine.
• Grapefruit Juice: Inhibits CYP3A4 and should be avoided during therapy.

Missed dose

If a dose is missed, it should be taken as soon as it is remembered. However, if it is almost time for the next scheduled dose, the missed dose should be skipped. Do not double the dose to make up for a missed one. Maintaining the regular 4-hour dosing interval is more important than catching up on a single missed dose. Inform the treating medical team of any missed doses.

Overdose

Overdose would be expected to manifest as profound systemic vasodilation leading to significant hypotension and reflex tachycardia. Other symptoms could include bradycardia (especially in patients on beta-blockers), dizziness, drowsiness, nausea, and gastrointestinal discomfort. In case of suspected overdose, medical attention must be sought immediately. Treatment is primarily supportive and symptomatic. This includes cardiovascular monitoring, Trendelenburg positioning, and administration of intravenous fluids. For severe, refractory hypotension, vasopressor agents (e.g., dopamine, norepinephrine) may be required. As nimodipine is highly protein-bound, dialysis is not likely to be of benefit.

Storage

Store Nimotop capsules at controlled room temperature, 20°C to 25°C (68°F to 77°F), with excursions permitted between 15°C and 30°C (59°F and 86°F). Keep the bottle tightly closed and protect from light and moisture. Dispense in the original, light-resistant container. Keep out of reach of children and pets. Do not use after the expiration date printed on the packaging.

Disclaimer

This information is for educational and informational purposes only and does not constitute medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any new treatment. Never disregard professional medical advice or delay in seeking it because of something you have read here. The content has been compiled from various sources and may not be entirely error-free or encompass all possible uses, directions, precautions, or interactions.

Reviews

• Neurologist, Academic Medical Center: “Nimotop remains a non-negotiable part of our protocol for aneurysmal SAH. While the evidence is strongest for good-grade patients, we see a tangible reduction in symptomatic vasospasm and cerebral infarction rates. The key is strict adherence to the 4-hour dosing schedule for the full 21 days.”
• Neurocritical Care Pharmacist: “Managing drug interactions is crucial, especially in an ICU setting where polypharmacy is common. We have a strict protocol to hold any strong CYP3A4 inhibitors during the Nimotop course. The nasogastric tube administration option is invaluable for our intubated patients.”
• Clinical Trial Data (Meta-Analysis): “Pooled analysis of randomized controlled trials continues to demonstrate a significant benefit of nimodipine in reducing poor outcomes (death and severe disability) following aneurysmal subarachnoid hemorrhage, with a relative risk reduction of approximately 30%.”
• Neurosurgery Resident: “It’s one of the few drugs in our arsenal with a proven mortality and morbidity benefit in this devastating condition. The hypotension can be a management challenge, but it’s usually manageable with fluid administration and occasionally pressor support.”