Nifedipine

Nifedipine

Generic Name: nifedipine (nye FED i peen)

Brand names: Adalat CC, Afeditab CR, Nifediac CC, Nifedical XL, Procardia, Procardia XL, Adalat

What is nifedipine?

Nifedipine is in a class of drugs called calcium channel blockers. It relaxes (widens) your blood vessels (veins and arteries), which makes it easier for the heart to pump and reduces its workload.

Nifedipine is used to treat hypertension (high blood pressure) and to treat angina (chest pain).

Nifedipine may also be used for other purposes not listed in this medication guide.

Important information about nifedipine

You should not use nifedipine if you are allergic to it.

Before taking nifedipine, tell your doctor if you have kidney or liver disease (especially cirrhosis), coronary artery disease, congestive heart failure, or digestive problems.

If you need surgery, tell the surgeon ahead of time that you are using nifedipine. You may need to stop using the medicine for a short time.

Many drugs can interact with nifedipine. Tell your doctor about all other medications you use.

Do not stop taking nifedipine without first talking to your doctor, even if you feel fine. Stopping suddenly may make your condition worse. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

Before taking nifedipine

You should not use nifedipine if you are allergic to it.

If you have any of these other conditions, you may need a dose adjustment or special tests:

kidney disease;

liver disease (especially cirrhosis);

coronary artery disease;

congestive heart failure; or

digestive problems.

FDA pregnancy category C. It is not known whether nifedipine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication. Nifedipine can pass into breast milk and may harm a nursing baby. Do not use nifedipine without telling your doctor if you are breast-feeding a baby.

See also: Nifedipine pregnancy and breastfeeding warnings (in more detail)

How should I take nifedipine?

Take nifedipine exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Your doctor may occasionally change your dose of nifedipine to make sure you get the best results.

Take the Adalat CC tablet on an empty stomach. Do not crush, chew, or break an extended-release tablet. Swallow it whole. Breaking the pill may cause too much of the drug to be released at one time.

Some tablet forms of nifedipine are made with a shell that is not absorbed or melted in the body. Part of the tablet shell may appear in your stool. This is a normal side effect of nifedipine and will not make the medication less effective.

Call your doctor if you have ongoing vomiting or diarrhea, or if you are sweating more than usual. These conditions can lead to severely low blood pressure.

If you need surgery, tell the surgeon ahead of time that you are using nifedipine. You may need to stop using the medicine for a short time. Do not stop taking nifedipine without first talking to your doctor, even if you feel fine. Stopping suddenly may make your condition worse. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

Your blood pressure will need to be checked often and you may need other blood tests at your doctor's office. Visit your doctor regularly.

Store nifedipine at room temperature away from moisture and heat.

See also: Nifedipine dosage (in more detail)

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra nifedipine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include severe dizziness, pounding heartbeats, nausea, vomiting, and feeling like you might pass out.

What should I avoid while taking nifedipine?

Grapefruit and grapefruit juice may interact with nifedipine and lead to potentially dangerous effects. Discuss the use of grapefruit products with your doctor. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall. Drinking alcohol can lower your blood pressure further and may increase certain side effects of nifedipine.

Nifedipine side effects

Get emergency medical help if you have any of these signs of an allergic reaction to nifedipine: hives; difficult breathing; swelling of your face, lips, tongue, or throat. Call your doctor at once if you have a serious side effect such as:

worsening angina;

feeling like you might pass out;

feeling short of breath, swelling in your hands or feet;

fast or pounding heartbeats;

numbness or tingly feeling;

jaundice (yellowing of the skin or eyes); or

chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling.

Less serious nifedipine side effects may include:

headache, dizziness;

drowsiness, tired feeling;

nausea, constipation, diarrhea, stomach pain;

sleep problems (insomnia);

mild rash or itching;

joint pain, leg cramps;

warmth, redness, or tingly feeling under your skin; or

urinating more than usual.

This is not a complete list of nifedipine side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Nifedipine side effects (in more detail)

Nifedipine Dosing Information

Usual Adult Dose for Hypertension:

Initial dose:

Nifedipine Extended release tablets: 30 to 60 mg orally once a day

Dosage can be increased gradually every 7 to 14 days.

Maximum dose:

Adalat (R) CC: 90 mg/day

Procardia XL (R): 120 mg/day

Usual Adult Dose for Migraine Prophylaxis:

Initial dose:

Nifedipine Extended release tablets: 30 mg orally once a day

Nifedipine Immediate release capsules: 10 mg orally 3 times a day

Usual Adult Dose for Angina Pectoris Prophylaxis:

Initial dose:

Nifedipine Extended release tablets: 30 to 60 mg orally once a day

Nifedipine Immediate release capsules: 10 mg orally 3 times a day

Dosage can be increased gradually every 7 to 14 days.

Maintenance dose:

Nifedipine Immediate release capsules: 10 to 30 mg orally 3 to 4 times a day

Maximum dose:

Extended release tablets:

Adalat (R) CC: 90 mg/day

Procardia XL (R): 120 mg/day

Immediate release capsules: 180 mg/day

Usual Adult Dose for Congestive Heart Failure:

Initial dose:

Procardia XL (R): 30 to 60 mg orally once a day

Adalat (R) CC: 30 mg orally once a day

Usual Adult Dose for Premature Labor:

The tocolytic properties of nifedipine have been evaluated in several studies. Doses used in these studies have ranged from 10 to 40 mg as an initial "one time" dose. Subsequent dosages have ranged from 10 to 20 mg every 6 to 8 hours as needed and tolerated to delay delivery.

Nifedipine Immediate release capsules are not approved by the FDA for the treatment of premature labor. In addition, their use in patients with hypertension is not recommended because of data that have revealed evidence of increased risk of adverse cardiovascular events associated with the use of short-acting nifedipine in patients with hypertension. Elderly patients with coronary artery disease may be at particular risk (unlikely to pertain to pregnant women).

Usual Pediatric Dose for Hypertensive Emergency:

Children:

Nifedipine Immediate release capsules: 0.25 to 0.5 mg/kg/dose (maximum 10 mg/dose) repeated every 4 to 6 hours if necessary

Maximum dose: 1 to 2 mg/kg/day

Initial doses less than or equal to 0.25 mg/kg/dose may result in a less dramatic decrease in blood pressure and be safer than larger initial doses. Some centers use initial doses of 0.1 mg/kg/dose.

Usual Pediatric Dose for Hypertension:

Nifedipine Extended release tablets:

Children: 0.25 to 0.5 mg/kg/day in 1 to 2 divided doses; dose should be titrated to effect

Maximum dose: 3 mg/kg/day up to 120 mg/day (or 180 mg/day in some centers)

Adolescents:

Initial dose: 30 mg orally once a day

Usual Pediatric Dose for Hypertrophic Cardiomyopathy:

Children: 0.6 to 0.9 mg/kg/24 hours in 3 to 4 divided doses

What other drugs will affect nifedipine?

Tell your doctor about all other medicines you use, especially:

acarbose (Precose);

cimetidine (Tagamet);

fentanyl (Actiq, Duragesic, Fentora) or other narcotic pain medications;

digoxin (Lanoxin);

nefazodone;

St. John's wort;

rifabutin (Mycobutin), rifampin (Rifadin, Rifater, Rifamate) or rifapentine (Priftin);

a blood thinner such as warfarin (Coumadin);

an antibiotic such as clarithromycin (Biaxin), dalfopristin/quinupristin (Synercid), or erythromycin (E.E.S., EryPed, Ery-Tab, Erythrocin);

antifungal medication such as fluconazole (Diflucan), itraconazole (Sporanox), or ketoconazole (Nizoral);

a beta-blocker such as atenolol (Tenormin, Tenoretic), carvedilol (Coreg), labetalol (Normodyne, Trandate), metoprolol (Lopressor, Toprol), nadolol (Corgard), propranolol (Inderal, InnoPran), sotalol (Betapace), timolol (Blocadren), and others;

a heart rhythm medication such as quinidine (Quin-G) or flecaininde (Tambocor);

HIV/AIDS medicine such as atazanavir (Reyataz), delavirdine (Rescriptor), fosamprenavir (Lexiva), indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Norvir), Kaletra, or saquinavir (Invirase);

medicines used to prevent organ transplant rejection, such as sirolimus (Rapamune) or tacrolimus (Prograf);

other heart or blood pressure medications such as benazepril (Lotensin), diltiazem (Cartia, Cardizem), doxazosin (Cardura), or verapamil (Calan, Covera, Isoptin, Verelan); or

seizure medication such as carbamazepine (Carbatrol, Tegretol), phenobarbital (Solfoton), or phenytoin (Dilantin).

This list is not complete and other drugs may interact with nifedipine. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

Where can I get more information?

Your pharmacist can provide more information about nifedipine.