Nifedipine

💊 What is Nifedipine used for?

• •The label says nifedipine extended-release tablets are used to treat high blood pressure (hypertension). They may be used alone or with other blood pressure medicines.

How it works

The label describes nifedipine as a calcium channel blocker and a vasodilator. It reduces peripheral vascular resistance, which means it relaxes and widens blood vessels. The label notes that its blood pressure effect is usually modest and well tolerated in most patients.

How it is usually taken

• •The label says the tablet should be swallowed whole and taken on an empty stomach, once daily. Do not chew, divide, or crush the tablet, and do not bite it. The label says it should not be taken with food. The label also says grapefruit juice should be avoided with this medicine. Dosing is adjusted to each person's needs, so follow the instructions from your prescriber or pharmacist.

Comes as

• •60 mg extended-release tablets (mustard yellow, unscored, round, film-coated; sold in bottles of 100)

⚠️ Nifedipine side effects

🛑 Who should not take Nifedipine, and who should be careful

The label says not to take it if

• 🚨The label says you should not take it with strong CYP3A inducers such as rifampin, because it may significantly reduce the medicine's effectiveness.
• 🚨The label says it must not be used in cases of cardiogenic shock.
• 🚨The label says it is not to be used if you have a known allergy (hypersensitivity) to any ingredient in the tablet.

Tell your doctor before taking it if

• •Tell your prescriber about all medicines you take, especially other blood pressure medicines and beta-blockers. The label says excessive low blood pressure may be more likely with beta-blockers.
• •The label says that if you are stopping a beta-blocker, its dose should be tapered rather than stopped suddenly before starting nifedipine.
• •Tell your care team if you have liver disease (cirrhosis). The label says the medicine clears more slowly in people with cirrhosis.
• •Tell your care team if you have tight aortic stenosis, because the label says these patients may be at greater risk of heart failure.
• •Tell your care team if you have severe obstructive coronary artery disease, because the label mentions a higher risk of worsening angina or heart attack in this group.
• •Tell your surgical team if you are planning surgery using high-dose fentanyl anesthesia. The label says at least 36 hours should be allowed for nifedipine to wash out of the body before surgery, if the patient's condition permits.
• •The label says that if your blood pressure is already low or you are taking medicines that lower blood pressure, your blood pressure should be carefully monitored when starting or adjusting the dose.

🔀 Nifedipine with other medicines, food and alcohol

The label says to discuss these with your doctor or pharmacist

• •Grapefruit and grapefruit juice: the label says grapefruit juice should be avoided because it may increase the amount of nifedipine in the body.
• •CYP3A inhibitors: the label lists ketoconazole, fluconazole, itraconazole, clarithromycin, erythromycin, nefazodone, fluoxetine, saquinavir, indinavir, nelfinavir, and ritonavir as medicines that may increase nifedipine levels. The label says careful monitoring and dose adjustment may be needed.
• •Strong CYP3A inducers: the label lists rifampin, rifabutin, phenobarbital, phenytoin, carbamazepine, and St. John's Wort as medicines that may reduce how well nifedipine works. Rifampin is contraindicated with this medicine.
• •Quinidine: the label says heart rate should be monitored when quinidine is added to nifedipine treatment.
• •Flecainide: the label says there is too little experience with this combination to recommend using them together.
• •Beta-blockers: the label says the risk of severe low blood pressure and fluid needs may be higher when nifedipine is combined with a beta-blocker, especially during surgery with high-dose fentanyl.
• •Other blood pressure medicines: the label says co-administration with drugs that affect blood pressure may cause additive effects.
• •Intravenous magnesium sulfate: the label says blood pressure should be carefully monitored in pregnant women receiving this combination.

Alcohol and food

The label says the tablet should be taken on an empty stomach and not with food. The label says grapefruit juice should be avoided. The label does not mention alcohol.

🤰 Nifedipine in pregnancy and breastfeeding

Pregnancy

The label lists this medicine as Pregnancy Category C. In animal studies (rodents, rabbits, and monkeys), nifedipine caused a range of harmful effects on embryos and fetuses at some doses. The label says that from the clinical evidence available, a specific prenatal risk has not been identified. However, it notes reports of increased perinatal asphyxia, cesarean delivery, prematurity, and intrauterine growth retardation. Blood pressure should be carefully monitored in pregnant women when nifedipine is combined with IV magnesium sulfate.

Breastfeeding

The label says nifedipine is excreted in human milk. Nursing mothers are advised not to breastfeed their babies while taking the drug.

🗓️ Storage, missed doses and taking too much

Storage

The label says to protect the tablets from light and moisture and store them at 25°C (77°F). Brief temperature changes between 15°C and 30°C (59°F and 86°F) are permitted. The label says the tablets should be kept in tight, light-resistant containers.

If a dose is missed

The label does not say.

If too much is taken

The label says experience with overdose is limited. Symptoms of severe overdose include loss of consciousness, a drop in blood pressure, heart rhythm problems, metabolic acidosis, low oxygen (hypoxia), and cardiogenic shock with pulmonary edema. The label says an overdose causing marked low blood pressure needs active cardiovascular support, including monitoring, elevating the legs, and treatments such as calcium infusion, pressor agents, and fluids. The label also mentions gastric lavage after oral ingestion, if needed.

🗒️ Questions to ask about Nifedipine

• Should I take this tablet at the same time each day, and how do I make sure I take it on an empty stomach?
• Are any of my current medicines, such as beta-blockers or antibiotics, known to interact with nifedipine?
• Will I need my blood pressure checked often when I start this medicine or when my dose changes?
• What should I do if I have chest pain or feel faint after starting this medicine?
• Do I need to stop or taper a beta-blocker before starting nifedipine?
• Do I need to tell my surgeon about this medicine before a procedure?
• What should I know about swelling in my legs while taking this medicine?

❓ Nifedipine: frequently asked questions