What is the most important information I should know about nifedipine?
You may not be able to use this medicine if your heart cannot pump blood properly, or if you also take rifampin.
Tell your doctor about all your current medicines and any you start or stop using. Many drugs can interact, and some drugs should not be used together.
What is nifedipine?
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.
What should I discuss with my healthcare provider before taking nifedipine?
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.
How should I take nifedipine?
Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.
Swallow the tablet or capsule whole and do not crush, chew, or break it.
Take the extended-release tablet on an empty stomach.
Your dose needs may change if you switch to a different brand, strength, or form of this medicine. Avoid medication errors by using only the form and strength your doctor prescribes.
Your blood pressure will need to be checked often and you may need other medical tests.
Keep using this medicine even if you feel well. Use all your heart or blood pressure medications as directed and read all medication guides you receive. Do not change your dose or stop taking your medicine without your doctor's advice.
You may have very low blood pressure while taking this medication. Call your doctor if you are sick with vomiting or diarrhea, or if you are sweating more than usual.
If you need surgery, tell the surgeon ahead of time that you are using nifedipine. You may need to stop using the medicine at least 36 hours before surgery.
Some tablets are made with a shell that is not absorbed or melted in the body. Part of this shell may appear in your stool. This is normal and will not make the medicine less effective.
Store in the original container at room temperature, away from moisture, heat, and light.
What happens if I miss a dose?
Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
Take the extended-release tablet without food.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
Overdose symptoms may include irregular heartbeats, severe dizziness, or fainting.
What should I avoid while taking nifedipine?
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.
What are the possible side effects of nifedipine?
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.
What other drugs will affect nifedipine?
If you have been using a beta-blocker medication (such as atenolol, carvedilol, metoprolol, propranolol, sotalol, and others), you should not stop using it suddenly. Follow your doctor's instructions about tapering your dose. Stopping a beta-blocker too quickly can cause serious heart problems that will not be prevented by nifedipine.
Tell your doctor about all your other medicines, especially other heart or blood pressure medications.
When you start or stop taking other medications, your doctor may need to adjust your nifedipine dose. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.
Many drugs can affect nifedipine, and some drugs should not be used at the same time. Tell your doctor about all your current medicines and any medicine you start or stop using. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.
Where can I get more information?
Your pharmacist can provide more information about nifedipine.
