Nifedipine

Generic Name: nifedipine (nye FEH dih peen)
Brand names: Adalat CC, Procardia, Procardia XL, Adalat, Nifedical XL, Nifediac CC, Afeditab CR

What is nifedipine?

Nifedipine is in a class of drugs called calcium channel blockers. Nifedipine 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 lower hypertension (high blood pressure) and to treat angina (chest pain).

Nifedipine may also be used for purposes other than those listed in this medication guide.

What is the most important information I should know about nifedipine?

Do not stop taking nifedipine without first talking to your doctor, even if you begin to feel better. If you stop taking the medication, your condition could become worse. Do not crush, chew, or break any form of nifedipine. Swallow the pills whole. Do not consume grapefruit or grapefruit juice during treatment with nifedipine. Nifedipine can interact with grapefruit and grapefruit juice, and the interaction may have dangerous effects. You should discuss the use of grapefruit and grapefruit juice with your doctor.

What should I discuss with my healthcare provider before taking nifedipine?

Before taking nifedipine, tell your doctor if you have

• kidney disease;

• liver disease;

• another disease of the heart or blood vessels such as sick sinus syndrome, aortic stenosis, heart failure, low blood pressure, or coronary artery disease.

You may not be able to take nifedipine, or you may require a dosage adjustment or special monitoring during treatment if you have any of the conditions listed above.

Nifedipine is in the FDA pregnancy category C. This means that it is not known whether nifedipine will be harmful to an unborn baby. Do not take nifedipine without first talking to your doctor if you are pregnant or could become pregnant during treatment. Nifedipine passes into breast milk. Do not take nifedipine without first talking to your doctor if you are breast-feeding a baby. If you are over 65 years of age, you may be more likely to experience side effects from nifedipine. Your doctor may prescribe a lower dose of this medication.

How should I take nifedipine?

Take nifedipine exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.

Take each dose with a full glass of water. Adalat CC should be taken on an empty stomach. Do not crush, chew, or break any form of nifedipine. Swallow the pills whole. Do not consume grapefruit or grapefruit juice during treatment with nifedipine. Nifedipine can interact with grapefruit and grapefruit juice, and the interaction may have dangerous effects. You should discuss the use of grapefruit and grapefruit juice with your doctor.

Occasionally, the Procardia XL tablet shell may be seen in the stool. This is not harmful. The medicine has been absorbed by the body and the tablet shell is designed to be eliminated in the stool.

Do not stop taking nifedipine without first talking to your doctor, even if you begin to feel better. If you stop taking the medication, your condition could become worse. Store nifedipine at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the missed dose and take only the next regularly scheduled dose. Do not take a double dose of this medication.

What happens if I overdose?

Seek emergency medical attention.

Symptoms of a nifedipine overdose include dizziness, weakness, chest pain, shortness of breath, fainting, an unusually fast or slow heartbeat, coma, slurred speech, and confusion.

What should I avoid while taking nifedipine?

Do not consume grapefruit or grapefruit juice during treatment with nifedipine. Nifedipine can interact with grapefruit and grapefruit juice, and the interaction may have dangerous effects. You should discuss the use of grapefruit and grapefruit juice with your doctor.

Follow any recommendations your doctor makes about diet or exercise.

Use caution when you stand or sit up from a lying position, especially if you wake up during the night. You may become dizzy when changing positions. Use alcohol cautiously. Alcohol may further lower blood pressure and increase drowsiness or dizziness while taking nifedipine.

Nifedipine side effects

If you experience any of the following serious side effects, stop taking nifedipine and contact your doctor immediately or seek emergency medical treatment:

• an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives);

• unusually fast or slow heartbeats;

• severe dizziness or fainting;

• psychosis;

• yellowing of the skin or eyes (jaundice); or

• swelling of the legs or ankles.

Other, less serious side effects may be more likely to occur. Continue to take nifedipine and talk to your doctor if you experience

• headache, fatigue, or tiredness;

• flushing;

• insomnia;

• vivid or abnormal dreams;

• nausea or constipation; or

• increased urination.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome. You may report side effects to FDA at 1-800-FDA-1088.

Nifedipine Dosing Information

Usual Adult Dose for Hypertension:

Initial dose:
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:
Extended release tablets: 30 mg orally once a day
Immediate release capsules: 10 mg orally 3 times a day

Usual Adult Dose for Angina Pectoris Prophylaxis:

Initial dose:
Extended release tablets: 30 to 60 mg orally once a day
Immediate release capsules: 10 mg orally 3 times a day

Dosage can be increased gradually every 7 to 14 days.

Maintenance dose:
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.

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:
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 Hypertrophic Cardiomyopathy:

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

What other drugs will affect nifedipine?

Before taking nifedipine, tell your doctor if you are taking any of the following drugs:

• another heart medication to treat the same or another condition;

• cimetidine (Tagamet, Tagamet HB);

• erythromycin (E-Mycin, E.E.S., Eryc, Ery-Tab, others);

• itraconazole (Sporanox) or ketoconazole (Nizoral);

• carbamazepine (Tegretol);

• phenytoin (Dilantin); or

• rifampin (Rifadin, Rimactane) or rifabutin (Mycobutin).

You may not be able to take nifedipine, or you may require a dosage adjustment or special monitoring if you are taking any of the medicines listed above.

Drugs other than those listed here may also interact with nifedipine or affect your condition. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines, including herbal products.

Where can I get more information?

• Your pharmacist has additional information about nifedipine written for health professionals that you may read.

• Remember, keep this and all other medicines out of the reach of children. Never share your medicines with others and only use this medication for the condition prescribed.

Where can I buy nifedipine?

You can buy nifedipine by any brand name such as Adalat at any reputable online pharmacy.