Nifedipine: Uses, Doses, Side Effects, and Practical Tips

Nifedipine is a calcium channel blocker used to lower blood pressure and treat angina. You will see immediate release and extended release forms; the ER tablets are usually taken once daily, while immediate release comes in 10 to 20 mg doses several times a day. Common brand names include Procardia and Adalat, but generic nifedipine is widely available and cheaper.

How it works: nifedipine relaxes the smooth muscle in blood vessels, which lowers resistance and reduces blood pressure. That can help chest pain by improving blood flow to the heart. It acts faster than many blood-pressure pills in immediate release form, which is why ER versions are preferred for steady control.

Typical doses and when to take it

For adults with high blood pressure the usual ER dose is 30 to 90 mg once daily. Immediate release tablets often use 10 to 20 mg every 4 to 6 hours, but doctors now favor ER for safety and steady control. For chronic stable angina, doses range from 30 to 60 mg ER daily, adjusted to effect. If you are prescribed ER tablets, swallow whole and do not crush or chew; follow the label about food—some ER formulations are best taken with meals, others on an empty stomach.

Side effects, interactions, and safety tips

The most common side effects are ankle swelling, headache, flushing, dizziness, and palpitations. Peripheral edema happens because blood vessels dilate; raising your legs, wearing compression stockings, or switching to a different drug can help. Serious but rare problems include severe low blood pressure or fast heartbeat. If you feel sudden chest pain, faint, or have a racing pulse, get medical help.

Avoid grapefruit and grapefruit juice—these boost nifedipine levels and can cause extra side effects. Also watch for interactions with strong CYP3A4 inhibitors such as ketoconazole, clarithromycin, and some HIV drugs. Combining nifedipine with other blood-pressure meds can lower blood pressure too much; your doctor will adjust doses. Nifedipine is metabolized by the liver, so people with liver problems need lower doses and closer follow-up.

Special situations: nifedipine is sometimes used in pregnancy to relax the uterus as a tocolytic and to control high blood pressure in pregnancy under close supervision. Do not use immediate release nifedipine as a first choice in a hypertensive emergency—current guidance favors controlled IV therapies and supervised care. Historically, sublingual nifedipine was used in emergencies, but that practice is discouraged because it can cause unpredictable drops in blood pressure.

Practical tips: keep a blood pressure log, check ankles for new swelling, and report severe dizziness or chest pain. Always tell your prescriber about other meds, supplements, and grapefruit. If you miss a dose, take it when you remember unless it is close to the next dose—do not double up. If you are thinking of stopping nifedipine, ask your doctor; sudden changes can worsen angina or blood pressure control.

Keep a current medication list, bring it to appointments, and ask the pharmacist about any potential interactions now.