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.

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 this medication. 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.

Before taking this medication, 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 this medication 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.

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.

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.

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