Nimodipine

Pronunciation: nye-MOE-di-peen.

Generic name: nimodipine
Brand names: Nymalize, Nimotop
Drug class: Dihydropyridine calcium channel blocker
Form: Capsule or oral solution (prefilled oral syringe) in the United States; tablets and a separate, differently formulated infusion solution for central intravenous use exist in some other countries as distinct licensed products.
Route: Oral, nasogastric, or gastric tube only (enteral). Never intravenous or any other parenteral route.
Legal status: Prescription-only medicine

Supply Rules Vary

Trade names by country: United States · Canada · Australia

Australia: Nimotop (5) · Full directory

What nimodipine is and how it works

Nimodipine is a calcium channel blocker used specifically to improve neurological outcome after a subarachnoid hemorrhage (bleeding around the brain, usually from a ruptured brain aneurysm), by reducing the incidence and severity of ischemic deficits related to blood-vessel narrowing (vasospasm). (1) (3)

Nimodipine is started in hospital, usually within 96 hours of the bleed, and continued for a defined 21-day course. It must only ever be given by mouth or through a feeding tube — never injected — because injecting it has caused death and serious harm.

Mechanism of action: how nimodipine works

Nimodipine is a dihydropyridine calcium channel blocker that inhibits calcium ion transfer into vascular smooth muscle cells, with relatively greater effect on cerebral arteries than systemic arteries, thought to relate to high lipophilicity and blood-brain-barrier penetration. Bioavailability after oral dosing averages about 13% due to high first-pass metabolism, and elimination is mediated by CYP3A4. (2) (1)

What nimodipine is used for

Subarachnoid hemorrhage from a ruptured intracranial (berry) aneurysm

Nimodipine improves neurological outcome by reducing the incidence and severity of ischemic deficits in adult patients with subarachnoid hemorrhage from a ruptured intracranial berry aneurysm, regardless of the patient's post-hemorrhage neurological grade (Hunt and Hess Grades I-V). It is not approved for brain bleeds caused by trauma or for non-aneurysmal hemorrhage. (1) (2)

Before taking nimodipine

Do not take / not appropriate for

Never allow nimodipine capsules or oral solution to be given intravenously or by any other injected (parenteral) route, including via a central line or IV push. Deaths and serious, life-threatening events (severe hypotension, bradycardia, cardiovascular collapse, cardiac arrest) have occurred when the contents of nimodipine capsules were injected. (all patients and all care settings) (1) (3)

Tell your clinician about

Any liver disease or cirrhosis, since nimodipine levels are increased and the dose usually needs to be reduced.
All other medicines, especially azole antifungals, certain HIV/HCV protease inhibitors, certain macrolide antibiotics (such as clarithromycin), and other strong CYP3A4 inhibitors or inducers, because these can significantly increase or reduce nimodipine's effect.
Any blood-pressure-lowering medicines, since nimodipine can add to their effect.
Pregnancy, plans for pregnancy, or breastfeeding.

(1) (2)

How to take nimodipine

Take nimodipine only by mouth, or have it given through a nasogastric or gastric feeding tube if you cannot swallow — never by injection.
The usual course is 60 mg every 4 hours for 21 consecutive days, started within 96 hours of the subarachnoid hemorrhage.
Take on an empty stomach — about 1 hour before a meal or 2 hours after a meal — because food reduces absorption.
If given via feeding tube, this is done by trained staff using the oral syringe supplied and labeled 'for oral use only,' followed by a saline flush; this is not a step for patients or family members to perform themselves.
Complete the full course as directed even if you feel well, and do not change the dose, route, or schedule yourself.

(1) (2) (3)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5)

Missed dose

Take the missed dose as soon as you remember, unless it is almost time for the next dose, in which case skip the missed dose and continue the regular schedule. Do not take a double dose. If you are unsure, ask the care team.

Overdose

There have been no reported cases of overdose from taking nimodipine by mouth as directed. If too much has been taken, or if nimodipine may have been given by injection in error, seek emergency medical care immediately or call a poison control center (in the United States, 1-800-222-1222); overdose or incorrect administration can cause dangerously low blood pressure requiring urgent treatment. (2) (3)

Side effects

Nimodipine is given during a serious hospital admission, so effects are monitored closely by the care team. The most common effect is low blood pressure.

Low blood pressure (hypotension)

What to notice: The most frequently reported adverse reaction; blood pressure is monitored closely during treatment.

What to do: Care team monitors and manages this; report dizziness or lightheadedness to staff. (2)

Headache, nausea, diarrhea, or slow/fast heartbeat

What to notice: Reported adverse reactions in clinical trials.

What to do: Report to the care team; do not adjust the dose yourself. (2) (1)

Signs of significant low blood pressure

What to notice: Dizziness, lightheadedness, fainting, or a noticeably irregular or very slow/fast heartbeat.

What to do: Tell the care team immediately; blood pressure and pulse are monitored throughout treatment, and the dose may need adjustment by the clinician. (2)

Serious warnings

Death or serious harm from injecting nimodipine (wrong-route medication error) — emergency

Symptoms: Not a patient-recognized symptom pattern — this is a fatal administration-route error. If nimodipine has been drawn into a syringe designed for injection, or if there is any doubt about the route just used, treat it as an emergency.

Action: Nimodipine must only ever be given enterally (by mouth or feeding tube). If an injection has occurred or is suspected, this is a medical emergency requiring immediate resuscitation and supportive care by the treating team; call for emergency help immediately. Nimodipine oral syringes are labeled 'for oral use only' specifically to prevent this error. (1) (2)

Severe hypotension — urgent

Symptoms: Marked dizziness, fainting, or collapse.

Action: Seek immediate medical attention; the care team may need to give cardiovascular support and adjust treatment. Do not attempt to manage this yourself. (2)

Interactions

Medicine or test	Effect	Action
Strong CYP3A4 inhibitors (e.g., clarithromycin, telithromycin, certain HIV protease inhibitors such as indinavir/nelfinavir/ritonavir/saquinavir, certain HCV protease inhibitors, azole antifungals such as ketoconazole/itraconazole/posaconazole/voriconazole, conivaptan, delavirdine, nefazodone)	Can significantly increase nimodipine blood levels and the risk of serious low blood pressure.	Concomitant use should generally be avoided; this decision is made by the prescribing team, not the patient. (2)
Moderate/weak CYP3A4 inhibitors (e.g., cimetidine, fluconazole, erythromycin, diltiazem, verapamil, amiodarone, fluoxetine, oral contraceptives) and grapefruit/grapefruit juice	May increase nimodipine levels and the risk of hypotension.	Blood pressure is monitored more closely; dose reduction may be made by the clinician. Avoid grapefruit and grapefruit juice. (2)
Strong CYP3A4 inducers (e.g., carbamazepine, phenobarbital, phenytoin, rifampin, St. John's wort)	May significantly reduce nimodipine's blood level and effectiveness.	Concomitant use should generally be avoided; managed by the prescribing team. (2)
Other blood-pressure-lowering medicines	May increase the blood-pressure-lowering effect of nimodipine or vice versa.	Blood pressure is monitored and doses adjusted by the clinical team. (2)

Pregnancy, breastfeeding, kidney/liver function, age

Patients with cirrhosis or significant liver impairment

Nimodipine blood levels are increased (bioavailability roughly doubles) in patients with cirrhosis, raising the risk of side effects. A lower dose (30 mg every 4 hours instead of 60 mg) and closer blood-pressure/pulse monitoring are used in this group. (2)

Pregnancy

There is not enough human data to establish nimodipine's risk in pregnancy. Animal studies showed adverse effects on development at some doses. Use is a decision the treating team makes based on the seriousness of the underlying subarachnoid hemorrhage. (2)

Breastfeeding

Nimodipine has been detected in human milk; there are no human data on effects on a breastfed infant. This should be discussed with the treating team, weighing the benefits of breastfeeding against the mother's clinical need for nimodipine. (2)

Children

Safety and effectiveness in pediatric patients have not been established. (2)

Older adults

Blood levels of nimodipine can be higher in older adults; dosing in elderly patients is approached cautiously by the clinical team, reflecting a greater likelihood of reduced liver, kidney, or heart function or other medicines being taken. (2)

Monitoring

Before starting

Confirm the diagnosis of aneurysmal subarachnoid hemorrhage and the timing window (start within 96 hours of the bleed).
Review liver function, current blood pressure, and all other medicines for CYP3A4 interactions before the first dose.
Ensure the administration route is enteral only, and that oral syringes are clearly labeled 'for oral use only' to prevent an injection error.

During treatment

Monitor blood pressure and pulse closely throughout the 21-day course, especially at treatment start and with any interacting medicine.
Watch for and act on signs of hypotension promptly.
Confirm the route of every dose is enteral, never intravenous, at every administration.
The prescriber will decide whether to reduce the dose in patients with cirrhosis per the labeled adjustment and monitor blood pressure/pulse more closely in this group.

(2) (1)

Storage

Store at controlled room temperature (20°C to 25°C / 68°F to 77°F), protect from light, and do not refrigerate or freeze. Keep out of reach of children. Follow the specific product's storage instructions on the label.

Study the drug class: Dihydropyridine calcium channel blockers

Professional information

Clinician-facing context only. Use the current local product information, dosing table, and administration protocol.

United States (FDA label — oral capsule and Nymalize oral solution)

Indication: Subarachnoid hemorrhage (Hunt and Hess Grades I-V)

Dose summary: 60 mg (or equivalent oral-solution volume) every 4 hours for 21 consecutive days, started within 96 hours of SAH onset, given 1 hour before or 2 hours after meals. Enteral administration only (oral, nasogastric, or gastric tube); never IV. Reduce to 30 mg every 4 hours in patients with cirrhosis.

Renal context: No specific renal-impairment dosing adjustment is described in the U.S. label; hepatic impairment (cirrhosis) requires a labeled dose reduction as above. (2) (1)

United Kingdom (EMC SmPC — Nimotop tablets and separate 0.02% solution for infusion)

Indication: Ischaemic neurological deficits following aneurysmal subarachnoid haemorrhage

Dose summary: UK product information includes both an oral tablet regimen (two tablets at 4-hourly intervals) and a separate, differently formulated intravenous infusion product administered via a central catheter under close monitoring — a distinct licensed product from the U.S. oral-only formulations. Do not extrapolate U.S. oral dosing to the UK infusion product or vice versa; use the exact local product information.

Renal context: Not extracted in this pass; refer to the current UK SmPC. (4)

Mechanism of action

Hepatic guidance

Bioavailability approximately doubles in patients with cirrhosis; reduce to 30 mg every 4 hours with closer blood-pressure/pulse monitoring, per the U.S. label.

Overdose note

No reports of overdose from oral administration. Expected effects relate to excessive vasodilation and marked systemic hypotension; manage with cardiovascular support and vasopressors. Nimodipine is highly protein-bound, so dialysis is unlikely to help. (2) (1)

Frequently asked questions

Why is it so important that nimodipine is never given by injection?

The oral capsule and oral-solution formulations are not designed or tested for injection. Deaths and serious, life-threatening events (severe low blood pressure, slow heart rate, cardiovascular collapse, cardiac arrest) have occurred when the contents of nimodipine capsules were drawn up and given intravenously in error. Nimodipine must only ever be swallowed or given through a feeding tube, using oral syringes clearly labeled 'for oral use only.' (1) (2)

Does nimodipine ever get given intravenously anywhere?

In the United States, no nimodipine product is approved for IV use — only oral capsules or oral solution. Some other countries separately license a differently formulated IV infusion solution for hospital use under close monitoring; this is a distinct, specially manufactured product, not the same as injecting an oral capsule or oral solution, which remains dangerous regardless of country. (4) (2)

Can I take nimodipine with food?

No — take it on an empty stomach, about 1 hour before or 2 hours after a meal, because food significantly reduces how much is absorbed. (2)

What is the mechanism of action of nimodipine?

What is the generic name of Nimodipine?

The generic name is nimodipine. It is sold under brand names including Nymalize, Nimotop. (1) (2)

What class of drug is nimodipine?

Nimodipine is classed as: Dihydropyridine calcium channel blocker. (1) (2)

References

NIMODIPINE capsule, liquid filled — prescribing informationDailyMed, U.S. National Library of Medicine · United States · accessed 2026-07-23 · source 1
NYMALIZE (nimodipine) oral solution — full prescribing informationFDA (accessdata.fda.gov) · United States · dated Revised 12/2020 · accessed 2026-07-23 · source 2
Nimodipine: MedlinePlus Drug InformationMedlinePlus, U.S. National Library of Medicine · United States · accessed 2026-07-23 · source 3
Nimotop 30mg Tablets — Summary of Product Characteristics (SmPC)electronic Medicines Compendium (UK) · United Kingdom · accessed 2026-07-23 · source 4
NIMOTOP nimodipine 30 mg tablets blister pack (ARTG 43100)Therapeutic Goods Administration (TGA), Australia · Australia · accessed 2026-07-23 · source 5

Brand names by country

Single-ingredient nimodipine names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

Nymalize30 mg/5mL, 60 mg0mL · azurity pharmaceuticals, inc.

Canada

NIMOTOP

Australia

Nimotop (5)current register product example · 30 mg tablets · See current TGA ARTG record

View brands in additional countries.