This medication is used to prevent certain types of chest pain (angina). It may allow you to exercise more and decrease the frequency of angina attacks. Nifedipine belongs to a class of medications known as calcium channel blockers. It works by relaxing blood vessels so blood can flow more easily. This medication must be taken regularly to be effective. It should not be used to treat attacks of chest pain when they occur. Use other medications (such as sublingual nitroglycerin) to relieve attacks of chest pain as directed by your doctor. Consult your doctor or pharmacist for details.

Older adults should discuss the risks and benefits of this medication with their doctor or pharmacist, as well as other possibly safer forms of nifedipine (such as the long-acting tablets).

This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

This drug may also be used for a certain blood circulation disorder (Raynaud's syndrome).

Take this medication by mouth with or without food as directed by your doctor, usually 3 times daily. Swallow this medication whole. Do not crush, chew, or break the capsule.

The dosage is based on your medical condition and response to treatment. Your doctor may gradually increase your dose. Follow your doctor's instructions carefully.

Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor or pharmacist says you may do so safely. Grapefruit can increase the chance of side effects with this medicine. Ask your doctor or pharmacist for more details.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.

Tell your doctor if your condition gets worse (for example, your chest pain worsens or is more frequent).

Dizziness, flushing, weakness, swelling ankles/feet, constipation, and headache may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.

Remember that this medication has been prescribed because your doctor 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 right away if you have any serious side effects, including:

• fast/irregular/pounding heartbeat
• fainting
• vision changes

Although this medication is effective in preventing chest pain (angina), some people who already have severe heart disease may rarely develop worsening chest pain or a heart attack after starting this medication or increasing the dose. Get medical help right away if you experience:

• worsening chest pain
• symptoms of a heart attack (such as chest/jaw/left arm pain, shortness of breath, unusual sweating)

A very serious allergic reaction to this drug is rare. However, get medical help right away 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 or at www.fda.gov/medwatch.

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

Before taking this medication, tell your doctor or pharmacist if you are allergic to it; 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:

• certain heart problems (such as heart failure, aortic stenosis)
• liver problems
• kidney problems

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Older adults may be more sensitive to the side effects of this drug, especially dizziness, constipation, or swelling ankles/feet.

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

This medication passes into breast milk. Consult your doctor before breastfeeding.

See also the How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Other medications can affect the removal of nifedipine from your body, which may affect how nifedipine works. Examples include apalutamide, enzalutamide, mitotane, St. John's wort, rifamycins (such as rifabutin, rifampin), drugs used to treat seizures (such as carbamazepine, phenobarbital, phenytoin), among others.

Some products have ingredients that could raise your heart rate or worsen your chest pain. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products, diet aids, or NSAIDs such as ibuprofen/naproxen).

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests (such as blood pressure, liver/kidney function, electrocardiogram) may be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).