Nifedipine is a calcium channel blocker that is used to treat hypertension (high blood pressure) or angina (chest pain).

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

You should not use nifedipine if you are allergic to it. You may not be able to use nifedipine if your heart cannot pump blood properly.

Some medicines can cause unwanted or dangerous effects when used with nifedipine. Your doctor may change your treatment plan if you also use:

• St. John's wort;
• an antibiotic--rifabutin, rifampin; or
• seizure medicine--carbamazepine, oxcarbazepine, phenobarbital, phenytoin.

Tell your doctor if you have ever had:

• a heart attack;
• very low blood pressure;
• severe narrowing of the aortic valve in your heart (aortic stenosis);
• congestive heart failure;
• cirrhosis or other liver disease;
• kidney disease; or
• diabetes.

Older adults may be more sensitive to the effects of this medicine.

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

You should not breastfeed while using nifedipine.

Nifedipine capsules or tablets may contain lactose. Tell your doctor if you have galactose intolerance, or severe problems with lactose (milk sugar).

Nifedipine is not approved for use by anyone younger than 18 years old.

Use Afeditab CR (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Call your doctor at once if you have:

• worsening chest pain;
• pounding heartbeats or fluttering in your chest;
• a light-headed feeling, like you might pass out;
• swelling in your hands or lower legs; or
• upper stomach pain, jaundice (yellowing of the skin or eyes).

You may have more severe or more frequent episodes of angina when you first start taking nifedipine or whenever your dose is changed.

Common side effects may include:

• swelling;
• flushing (warmth, redness, or tingly feeling);
• headache, dizziness;
• nausea, heartburn; or
• feeling weak or tired.

This is not a complete list of 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.

Grapefruit may interact with nifedipine and lead to unwanted side effects. Avoid the use of grapefruit products.

Avoid taking an herbal supplement containing St. John's wort.

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.