Nifedipine (/nəˈfɛdəpin/ nə-FEH-də-peen), sold under the brand name Procardia among others, is a calcium channel blocker medication used to manage angina, high blood pressure, Raynaud's phenomenon, and premature labor. It is one of the treatments of choice for Prinzmetal angina. It may be used to treat severe high blood pressure in pregnancy. Its use in preterm labor may allow more time for steroids to improve the baby's lung function and provide time for transfer of the mother to a well-qualified medical facility before delivery. It is a calcium channel blocker of the dihydropyridine type. Nifedipine is taken by mouth and comes in fast- and slow-release formulations.

Common side effects include lightheadedness, headache, feeling tired, leg swelling, cough, and shortness of breath. Serious side effects may include low blood pressure and heart failure. Nifedipine is considered safe in pregnancy and breastfeeding.

Nifedipine was patented in 1967 and approved for use in the United States in 1981. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication. In 2023, it was the 120th most commonly prescribed medication in the United States, with more than 5 million prescriptions.

The approved uses are for the long-term treatment of hypertension and angina pectoris. In hypertension, recent clinical guidelines generally favour diuretics and ACE inhibitors, although calcium channel antagonists, along with thiazide diuretics, are still favoured as primary treatment for patients over 55 and black patients.

Nifedipine given as sublingual administration has previously been used in hypertensive emergencies. It was once frequently prescribed on an as-needed basis to patients taking MAOIs for real or perceived hypertensive crises. This was found to be dangerous, and has been abandoned. Sublingual administration of nifedipine promotes a hypotensive effect via peripheral vasodilation. It can cause an uncontrollable decrease in blood pressure, reflex tachycardia, and a steal phenomenon in certain vascular beds. There have been multiple reports in the medical literature of serious adverse effects with sublingual nifedipine, including cerebral ischemia/infarction, myocardial infarction, complete heart block, and death. As a result of this, in 1985 the FDA reviewed all data regarding the safety and effectiveness of sublingual nifedipine for the management of hypertensive emergencies, and concluded that the practice should be abandoned because it was neither safe nor effective. An exception to the avoidance of this practice is in the use of nifedipine for the treatment of hypertension associated with autonomic dysreflexia in spinal cord injury.

Nifedipine has been used frequently as a tocolytic (agent that delays premature labor). A Cochrane review has concluded that it has benefits over placebo or no treatment for prolongation of pregnancy. It also has benefits over beta-agonists and may also have some benefits over atosiban and magnesium sulfate, although atosiban results in fewer maternal adverse effects. No difference was found in the rate of deaths among babies around the time of birth, while data on longer-term outcomes is lacking.

Raynaud's phenomenon is often treated with nifedipine. A 2005 meta-analysis showed modest benefits (33% decrease in attack severity, 2.8–5 reduction in absolute number of attacks per week); it does conclude that most included studies used low doses of nifedipine.

Topical nifedipine has been shown to be as effective as topical nitrates for anal fissures.