Treating certain kinds of angina (chest pain). It may also be used for other conditions as determined by your doctor.

Nifedipine is a calcium channel blocking agent. It works by interfering with the normal action of calcium in blood vessel constriction (relaxes the blood vessels) and heart muscle contraction (heart may beat with less force and pump out less blood) and nerve conduction in the heart (heart may beat more slowly and more regularly). Calcium channel blockers are used to dilate (widen) the arteries of the heart and other arteries (reduce angina chest pain and reduce elevated blood pressure), and stabilize the heart rhythm in conditions in which the heart is beating too fast or in an irregular rhythm (antiarrhythmic effects).

Its main uses are in angina pectoris (especially Prinzmetal's angina) and hypertension, although a large number of other uses have recently been found for this agent, such as Raynaud's phenomenon, premature labor, and painful spasms of the esophagus in cancer and tetanus patients.

Do NOT use Nifedipine if:

• you are allergic to any ingredient in Nifedipine

Contact your doctor or health care provider right away if any of these apply to you.

Before using Nifedipine :

Some medical conditions may interact with Nifedipine. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have heart valve problems, heart failure, heart shock, heart disease, had a heart attack, swelling of the hands or feet, a slow heart rate, low blood pressure, or fluid in your lungs
• if you have recently had or will be having surgery, or if you have recently stopped taking a beta-blocker (eg, propranolol)

Some MEDICINES MAY INTERACT with Nifedipine. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Barbiturates (eg, phenobarbital), carbamazepine, or rifampin because they may decrease Nifedipine 's effectiveness
• Beta-blockers (eg, propranolol), cimetidine, cyclosporine, fluconazole, fluoxetine, imatinib, itraconazole, ketanserin, magnesium salts (eg, injectable magnesium sulfate), quinazolines (eg, metolazone), quinidine, or ranitidine because side effects, including very low blood pressure, may occur
• Beta-blockers (eg, propranolol), cyclosporine, digoxin, hydantoins (eg, phenytoin), ketanserin, lithium, theophylline, vinca alkaloids (eg, vincristine) because the actions and side effects of these medicines may be increased
• Quinidine, theophylline, or vinca alkaloids (eg, vincristine) because their effectiveness may be decreased by Nifedipine

This may not be a complete list of all interactions that may occur. Ask your health care provider if Nifedipine may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Nifedipine :

Use Nifedipine as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Take Nifedipine by mouth with or without food.
• Do not eat grapefruit or drink grapefruit juice while you use Nifedipine.
• Swallow Nifedipine whole. Do not break, crush, or chew before swallowing.
• If you miss a dose of Nifedipine , take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Nifedipine.

Important safety information:

• Nifedipine may cause dizziness or lightheadedness. These effects may be worse if you take it with alcohol or certain medicines. Use Nifedipine with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
• Proper dental care is important while you are taking Nifedipine. Brush and floss your teeth and visit the dentist regularly.
• Use Nifedipine with caution in the ELDERLY; they may be more sensitive to its effects.
• PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Nifedipine while you are pregnant. It is not known if Nifedipine is found in breast milk. If you are or will be breast-feeding while you use Nifedipine , check with your doctor. Discuss any possible risks to your baby.

Possible side effects of Nifedipine :

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Constipation; dizziness; flushing; giddiness; headache; heat sensation; heartburn; lightheadedness; nausea; weakness.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); irregular pulse; shortness of breath; swelling of the feet or hands; tender, bleeding, or swollen gums.