nimodipine
Nimotop

Available forms
Available by prescription only
Capsules: 30 mg

Indications and dosages
 Improvement of neurologic deficits after subarachnoid hemorrhage from ruptured congenital aneurysms. Adults: 60 mg P.O. q 4 hours for 21 days. Therapy should begin within 96 hours of subarachnoid hemorrhage.
≡ Dosage adjustment. For adults with hepatic impairment, 30 mg P.O. q 4 hours.
 Migraine headache ◇. Adults: 120 mg P.O. daily in divided doses, 1 hour before or at least 2 hours after meals.

Pharmacodynamics
Neuronal-sparing action: Inhibits calcium ion influx across cardiac and smooth muscle cells, thus decreasing myocardial contractility and oxygen demand, and dilates coronary arteries and arterioles. Although exact mechanism unknown, it’s believed that dilation of the small cerebral resistance vessels with increased collateral circulation is possible.

Pharmacokinetics
Absorption: Well absorbed after oral administration. However, because of extensive first-pass metabolism, bioavailability is only about 3% to 30%.
Distribution: More than 95% protein-bound.
Metabolism: Extensively metabolized in liver. Drug and metabolites undergo enterohepatic recycling.
Excretion: Less than 1% excreted as parent drug. Elimination half-life is 1 to 9 hours.

Contraindications and precautions
No known contraindications. Use cautiously in patients with hepatic failure.

Interactions
Drug-drug. Antihypertensives: Enhances hypotensive effect. Monitor patient’s blood pressure.
Calcium channel blockers: May enhance CV effects of these drugs. Monitor patient closely.
Phenytoin: Increases phenytoin levels. Monitor serum phenytoin levels.
Drug-food. Any food: Decreases absorption. Give drug 1 hour before or 2 hours after meals.

Adverse reactions
CNS: headache, psychic disturbances.
CV: decreased blood pressure, flushing, edema, tachycardia.
GI: nausea, diarrhea, abdominal discomfort.
Musculoskeletal: muscle cramps.
Respiratory: dyspnea.
Skin: dermatitis, rash.

Effects on lab test results
None reported.

Overdose and treatment
Overdose may cause nausea, weakness, drowsiness, confusion, bradycardia, and decreased cardiac output.
 Calcium gluconate I.V. has been used to treat calcium channel blocker overdose.

Special considerations
• Unlike other calcium channel blockers, nimodipine isn’t used for angina pectoris or hypertension.
• Use lower doses in patients with hepatic cirrhosis. Start therapy at 30 mg P.O. every 4 hours, and closely monitor blood pressure and heart rate.
• If patient can’t swallow capsules, puncture ends of liquid-filled capsule with an 18G needle and draw the contents into syringe. Instill dose into patient’s nasogastric tube and rinse tube with 30 ml of normal saline solution.
Pediatric patients
• Safety and efficacy in children haven’t been established.
Breast-feeding patients
• Substantial amounts of drug may appear in breast milk. Advise against breast-feeding during therapy.

Patient education
• Advise patient to rise from supine position slowly to avoid dizziness and hypotension, especially at start of therapy.
• Food decreases absorption. Advise patient to take drug 1 hour before or 2 hours after meals.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use