SIDE EFFECTS: Headache, dizziness, nausea, flushing, constipation, leg/muscle cramps, or sexual problems may occur. To reduce dizziness and lightheadedness, get up slowly when rising from a sitting or lying position. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

An empty tablet shell may appear in your stool. This is harmless since your body has already absorbed the medication.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: swelling of the ankles/feet, shortness of breath, unusual weakness/tiredness.

Tell your doctor immediately if any of these rare but very serious side effects occur: fast/slow/irregular heartbeat, fainting, mental/mood changes, swollen/tender gums, vision changes, severe constipation, severe stomach/abdominal pain, black stools.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Read the Procardia XL (nifedipine extended release tablets) Side Effects Center for a complete guide to possible side effects »

PRECAUTIONS: Before taking this medication, tell your doctor or pharmacist if you are allergic to it; or to other calcium channel blockers (e.g., amlodipine, felodipine); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: heart diseases (e.g., congestive heart failure, aortic stenosis), liver problems, esophagus/stomach/intestine problems (e.g., narrowing/stricture, motility disorders, obstruction), kidney problems, a certain metabolic disorder (porphyria).

Before having surgery, tell your doctor or dentist that you are taking this medication.

This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

Nifedipine passes into breast milk. While there have been no reports of harm to nursing infants, consult your doctor before breast-feeding.