Examples

How It Works

Nifedipine is a calcium channel blocker medicine that slows smooth muscle function. Muscles need calcium to function properly, and a calcium channel blocker interferes with the supply of calcium to the muscle. This allows the smooth muscle wall of the blood vessels to relax and widen, reducing blood pressure.

Why It Is Used

Nifedipine is sometimes used in late pregnancy to control moderate to severe high blood pressure.¹

Among the general population, nifedipine is used to treat migraines, high blood pressure, and heart problems.

How Well It Works

Nifedipine effectively lowers high blood pressure.² The capsule form works quickly, lowering blood pressure after 30 minutes, and it is used under medical supervision for severe high blood pressure. The tablet form becomes effective within a few hours and is used for moderate to severe high blood pressure.¹

Side Effects

Side effects of nifedipine include:

• Fluid retention.
• Constipation.
• Low blood pressure.
• Dizziness, lightheadedness, and nervousness.
• Skin flushing or redness.
• Headache.
• Nausea.
• Muscle cramps or tremors.

Rapid lowering of blood pressure with this medicine may affect blood flow to the placenta and fetus. It is therefore done under close medical supervision.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Nifedipine is not as commonly used as methyldopa but is used about as often as labetalol for treating high blood pressure during pregnancy.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

References

Citations

1. Magee LA (2001). Antihypertensives. Best Practice and Research: Clinical Obstetrics and Gynaecology, 15(6): 827–845.
2. Duley L (2005). Pre-eclampsia and hypertension, search date November 2004. Online version of Clinical Evidence (14): 1776–1790.