Calcium channel blocker

Nimodipine (Nymalize)

Also called Nymalize, Nimotop

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Indications

Aneurysmal SAH, all grades: improves neurologic outcome by reducing the incidence and severity of ischemic deficits; start within 96 h and give for 21 days (label; AHA/ASA 2023 Class 1)
Prevention of delayed cerebral ischemia and infarction after aneurysmal SAH, by mouth or tube (NCS 2023, strong recommendation)

Mechanism of action

Nimodipine is a dihydropyridine that blocks L-type calcium channels and so inhibits calcium entry into vascular smooth muscle (label). In animals it acts more on cerebral than on other arteries, perhaps because it is lipophilic enough to cross the blood–brain barrier; CSF levels up to 12.5 ng/mL have been measured (label). The trials showed fewer and milder ischemic deficits without arteriographic evidence that it prevents or relieves large-artery spasm, and the precise mechanism in SAH is unknown (label); an effect on small vessels and neurons is the usual explanation.

Pharmacology

Neurologic: in good-grade patients, severe spasm-related deficits 1 of 56 vs 8 of 60 and 2 of 31 vs 10 of 39 with placebo (label)
Neurologic: in a 554-patient trial of all grades, the combined rate of infarction and severely disabling outcome fell; severe disability 12 vs 31 patients, deaths 43 vs 60 (label)
Cardiovascular: systemic vasodilation; hypotension in about 5% vs 1% with placebo (label); bradycardia about 1%
CNS and GI: headache and nausea, each about 1% (label)

Pharmacokinetics

Peak	0.25–1.05 h for the solution; generally within 1 h for capsules (labels)
Half-life	1–2 h early, which sets the every-4-h schedule; terminal 8–9 h (label)
Bioavailability	About 13%, from heavy first-pass metabolism (label)
Protein binding	Over 95% (label)
Metabolism	CYP3A4 (label)
Elimination	As metabolites; under 1% unchanged in urine (label)
Organ failure	Cirrhosis: 30 mg every 4 h with close BP and pulse checks (labels)
Routes	Enteral only: the 6 mg/mL solution by mouth or tube, flushed with 10 mL saline (Nymalize label); capsule contents drawn into an oral syringe and flushed down the tube with 30 mL saline (capsule label)

Chemistry

Isopropyl 2-methoxyethyl 1,4-dihydro-2,6-dimethyl-4-(m-nitrophenyl)-3,5-pyridinedicarboxylate, C₂₁H₂₆N₂O₇, MW 418.5: a dihydropyridine like nicardipine and clevidipine (label)
Yellow crystalline solid, practically insoluble in water (label), hence liquid-filled 30 mg capsules and an oral solution
Nymalize: 6 mg/mL in polyethylene glycol 400, glycerin, ethanol and methylparaben, in single-dose oral syringes (60 mg/10 mL, 30 mg/5 mL) or an 8 oz bottle; room temperature, protect from light, do not refrigerate (label)

Adverse effects and cautions

Safety

Boxed warning (capsules): never give IV or by any other parenteral route; injected capsule contents have caused deaths and life-threatening events, including cardiac arrest, cardiovascular collapse, hypotension and bradycardia (label). Draw it up only in an oral syringe that cannot take a needle, labeled not for IV use
Hypotension: monitor BP and treat it so the full dose can continue; splitting to 30 mg every 2 h is practice, not label
Strong CYP3A4 inhibitors (clarithromycin, azole antifungals, HIV protease inhibitors, nefazodone) are contraindicated with the capsules; avoid grapefruit (label)
Strong CYP3A4 inducers (rifampin, carbamazepine, phenobarbital, phenytoin, St. John's wort) can sharply cut levels and efficacy: generally avoid (label)
Adds to the effect of other antihypertensives (label)

In the one-pagers

Neuro: ICP and StrokeAneurysmal subarachnoid hemorrhage: Nimodipine 60 mg enterally every 4 h for 21 days improves outcome without preventing spasm; if BP falls, 30 mg every 2 h. Never give capsule contents IV (FDA warning after deaths).

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Sources

FDA label: Nimodipine capsules (Bionpharma, 2022)
FDA label: Nymalize (Azurity, 2024)
AHA/ASA aSAH guideline (Hoh 2023)
NCS aSAH guideline (Treggiari 2023)

For education and exam preparation only. Follow your institution’s protocols. Typical adult values for study. Follow your local protocols and medical direction.