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. 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 any of these unlikely but serious side effects occur: swelling of the ankles/feet, shortness of breath, unusual weakness/tiredness. Tell your doctor right away if any of these rare but very serious side effects occur: fast/slow/irregular heartbeat, fainting, mental/mood changes, swollen/tender gums, 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, 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 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.

HOW TO USE: Take this medication by mouth on an empty stomach, usually once daily or as directed by your doctor. Do not crush or chew this medication. Doing so can release all of the drug at once, increasing the risk of side effects. Also, do not split the tablets unless they have a score line and your doctor or pharmacist tells you to do so. Swallow the whole or split tablet without crushing or chewing. Your doctor may gradually increase your dose. Follow your doctor's instructions carefully. Dosage is based on your medical condition and response to treatment. Avoid eating grapefruit or drinking grapefruit juice while being treated with this medication unless your doctor instructs you otherwise. Grapefruit juice can increase the amount of certain medications in your bloodstream. Consult your doctor or pharmacist for more details. Use this medication regularly in order to get the most benefit from it. Remember to use it at the same time each day. Keep taking this medication even if you feel well. Most people with high blood pressure do not feel sick. Do not suddenly stop taking this medication without consulting your doctor. Your condition may become worse when the drug is suddenly stopped. Your dose may need to be gradually decreased. Tell your doctor if your condition worsens (e.g., increase in your routine blood pressure readings).

PRECAUTIONS: Before taking this medication, tell your doctor or pharmacist if you are allergic to it; or to other calcium channel blockers (e.g., felodipine, amlodipine); 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 problems (e.g., congestive heart failure, aortic stenosis), liver problems, 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. 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). 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.

DRUG INTERACTIONS: See also 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. Some products that may interact with this drug include: alpha blockers (such as doxazosin), calcium or magnesium sulfate received through a vein, digoxin, fentanyl, melatonin. Other medications can affect the removal of nifedipine from your body, which may affect how nifedipine works. Examples include apalutamide, cimetidine, enzalutamide, mitotane, quinupristin/dalfopristin, St. John's wort, rifamycins (such as rifabutin, rifampin), drugs used to treat seizures (such as carbamazepine, phenytoin), among others. Some products have ingredients that could raise your heart rate or blood pressure. 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).

OVERDOSE: 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 their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe dizziness, fainting, fast/slow/irregular heartbeat.