Nimodipine (Nymalize)

ED / ICU / Transport

• Aneurysmal subarachnoid hemorrhage (aSAH) from a ruptured intracranial berry aneurysm: FDA-labeled to improve neurologic outcome by cutting the incidence and severity of ischemic deficits. That covers every Hunt and Hess grade, from I to V. Start within 96 hr of onset.
• Standard care in aSAH: per the 2023 AHA/ASA guideline (Class 1, LOE A), early enteral nimodipine is beneficial. It helps prevent delayed cerebral ischemia and improves functional outcomes.
• Interfacility transfer: the 21-day course does not stop for the ride. It carries through transport and handoff. Plan the every-4-hour doses around the transfer.

Other Uses

• IV or intra-arterial nimodipine for refractory vasospasm (off-label): no IV nimodipine is marketed in the US. All US labeling is enteral only, so see Contraindications for the IV warning. Intra-arterial vasodilator therapy for severe vasospasm with DCI is a specialist neuro-interventional procedure. It is not bedside or transport care. The 2023 AHA/ASA guideline rates it 2b, B-NR ("may be reasonable"). It also notes that intra-arterial nimodipine is not available in all geographic regions.

The US label lists no other indication.

Doses vary by protocol; follow local protocols and medical direction.

Available Forms

• Nymalize oral solution, 6 mg/mL: 60 mg per 10 mL unit-dose prefilled oral syringe (the usual 60 mg dose); 30 mg per 5 mL prefilled oral syringe, also in an ENFit connector version; 60 mg per 10 mL in an 8 oz (237 mL) bottle. Only the 30 mg/5 mL syringe has an ENFit connector. The 60 mg/10 mL syringe does not. Check tube-connector compatibility with pharmacy before giving 60 mg doses through an ENFit-only tube.
• Nimodipine capsules, 30 mg soft gelatin (generic, several manufacturers): 60 mg is two capsules. That is where the IV boxed warning comes from: the capsule labeling.
• Transport: send the dispensed product with the patient; confirm the strength on the label at handoff.

Adult Dosing

Pediatric Dosing

Preparation & Administration

• Dilution: none. The oral solution goes in as supplied, from the labeled prefilled oral syringe.
• Route and syringe: enteral only. Use the labeled oral syringe. Never connect it to IV tubing or a needle.
• NG or gastric tube (Nymalize): for each dose, the syringe is refilled with 10 mL of 0.9% saline, and any remaining contents are flushed from the tube into the stomach.
• NG or gastric tube (capsule labeling): the contents go into the tube, and a 30 mL wash of 0.9% saline follows.
• Capsules that cannot be swallowed: each end gets a hole from an 18-gauge needle, and the liquid is drawn into a syringe that cannot accept a needle, labeled "Not for IV Use". Give by mouth or tube.
• Food: give 1 hr before or 2 hr after meals. In the capsule study, breakfast cut peak level by 68% and bioavailability by 38%.
• Storage: Store at 20–25°C (68–77°F), protected from light. Do not refrigerate.

Contraindications

• IV or any parenteral route: never. Injected capsule contents have been followed by deaths and serious events, including cardiac arrest, cardiovascular collapse, hypotension and bradycardia.
• Strong CYP3A4 inhibitors (capsule labeling: contraindicated): clarithromycin, telithromycin, ketoconazole, itraconazole, voriconazole, HIV protease inhibitors (for example ritonavir, indinavir, nelfinavir, saquinavir) and nefazodone. The Nymalize label lists no contraindications. It does say to avoid these drugs.

Precautions

• Hypotension: About 5% of nimodipine-treated patients had hypotension in SAH trials, against 1% on placebo. About 1% stopped the drug because of it.
• Cirrhosis: Exposure runs higher, and so do adverse reactions. Use the 30 mg dose and monitor BP and pulse.
• Other antihypertensives: diuretics, beta-blockers, ACE inhibitors, ARBs, other calcium channel blockers, alpha-blockers, PDE5 inhibitors and methyldopa all stack on the BP-lowering effect.
• Heart failure and AV conduction: as a calcium channel blocker, nimodipine may worsen heart failure or affect AV conduction in susceptible patients. SAH trials did not see these effects.
• Older adults: a single-dose study in 59- to 79-year-olds showed about 2-fold higher exposure. The label advises cautious dosing.

Hold / Reassess If

• Hypotension: reduce or hold per protocol. The US label sets no threshold.
• Falling heart rate or new ECG change: obtain a 12-lead ECG and reassess the dose.
• New focal deficit after a BP drop: urgent team review of the BP target.
• Strong CYP3A4 inhibitor or inducer started or stopped: reassess the dose and BP.

Common

• Decreased blood pressure is the most common adverse event. It hit 4.4% of nimodipine-treated patients in SAH trials.
• Headache, nausea, diarrhea, rash and edema each showed up in more than 1% of SAH trial patients at some doses (Nymalize section 6.1 table): headache 1.2% at 60 mg; nausea 1.2% at 60 mg; diarrhea 4.2% at 30 mg; rash 2.4% at 0.35 mg/kg and 1.2% at 90 mg; edema 1.2% at 90 mg.
• Tachycardia, EKG abnormality and bradycardia appeared in about 1% or more of trial patients at some doses (bradycardia 1.0% at 60 mg).

Serious / Life-Threatening

Overdose & Toxicity Management

• Signs: No overdose has been reported with oral nimodipine. Expect vasodilation and marked systemic hypotension.
• Immediate: Stop the drug. Support BP with pressor agents per protocol (label).
• Specific treatment: treat as calcium channel blocker overdose per toxicology protocol. See calcium chloride and glucagon.
• Dialysis: not likely to help. Nimodipine is highly protein-bound.
• Accidental IV or parenteral dose: monitor BP, heart rate and rhythm continuously. Expect pressor need. Treat as above.

Clinically Significant Interactions

No IV compatibility question arises. Nimodipine is not given IV.

• Pediatrics: safety and effectiveness are not established. Specialist use only. See the Pediatric Dosing table, since no pediatric dose is listed.
• Pregnancy: there are no adequate human data. Rabbit studies showed malformations and stunted fetuses at doses below the human dose (body-surface basis). Rat studies showed embryotoxicity at higher doses. The label asks patients to tell the prescriber if pregnant. Weigh the benefit with the treating team.
• Lactation: nimodipine shows up in human milk. There are no data on effects on the breastfed infant. Weigh the maternal need against infant exposure.
• Older Adults: a single-dose study in 59- to 79-year-olds showed about 2-fold higher exposure than in younger adults. The label advises cautious dosing.
• Renal Impairment: no specific adjustment is established. Less than 1% of the dose comes out unchanged in the urine.
• Hepatic Impairment: in cirrhosis, peak levels about double. Reduce to 30 mg every 4 hr, with close BP and heart-rate monitoring. The capsule label applies the same reduction to severely disturbed liver function.
• Obesity / Dosing Weight: dosing is fixed in mg. Labeling makes no weight-based adjustment.

• Scope: enteral dosing falls to the team managing the tube. It varies by state and agency protocol.
• Storage & Stability: 20–25°C (68–77°F). Protect from light. Do not refrigerate. Keep the carton. Do not leave it in a hot vehicle or in direct sun.
• Carried Concentration: one concentration (6 mg/mL) comes in two syringe volumes. Check the 60 mg/10 mL or 30 mg/5 mL syringe against the order. That check prevents a half-dose or double-dose error.
• Infusions in Transport: none. Do not connect any nimodipine syringe to IV tubing or a line.
• Altitude / Environment: no label data.
• Handoff Essentials: time of the last dose and the next due time (every 4 hr), day of the 21-day course, route (NG or oral), BP trend and response to any change, and cirrhosis status.

Mechanism of Action

• Target: dihydropyridine blockade. Less calcium gets into vascular smooth muscle, so it contracts less.
• Cerebral effect: in animal studies it acts more on cerebral arteries than on systemic ones. It is highly lipophilic, so it crosses the blood-brain barrier. Up to 12.5 ng/mL was measured in CSF of treated patients.
• Clinical effect: It reduces the incidence and severity of ischemic deficits after aSAH. The label says there is no arteriographic evidence that it prevents or relieves vasospasm.
• Consequence: Systemic vasodilation. That is what causes the hypotension that limits therapy.

Pharmacokinetics

• Half-life: terminal half-life is 8–9 hr, with an early phase of 1–2 hr. That is why doses are every 4 hr. Three-times-daily dosing for 7 days shows no accumulation.
• Metabolism: It is metabolized by CYP3A4, with high first-pass metabolism. Oral bioavailability is about 13%.
• Active metabolites: There are numerous metabolites. They are inactive or much less active than the parent drug.
• Elimination: almost all of it leaves as metabolites. Less than 1% is excreted unchanged in urine.
• Protein binding: over 95%, whatever the concentration. Dialysis is not likely to help.

Generic Name

Nimodipine

Brand Names

Nymalize (oral solution, US). Generic oral solution and 30 mg capsules are also marketed

Pharmacologic Class

Dihydropyridine calcium channel blocker

Therapeutic Class

Neuroprotective agent for aneurysmal SAH (enteral only)

Controlled Substance

Not controlled

ISMP High-Alert

No: not on the ISMP acute-care high-alert list

Look-Alike / Sound-Alike

None on the ISMP confused-drug-names list checked; name is similar to nicardipine (see Pearls)

Error-Prone Abbreviations to Avoid

None