Nifedipine
A dihydropyridine calcium channel blocker used for angina, high blood pressure and Raynaud's phenomenon.
Drug card
- How it works
- Blocking L-type calcium channels in artery walls, so arteries widen
- Used for
- High blood pressure
- Angina, especially vasospastic (Prinzmetal) angina
- Raynaud's phenomenon
- Known for
- Ankle swelling (edema), dose-related
- Flushing and a feeling of heat
- Gum overgrowth (gingival hyperplasia)
- Its name
- -dipine means a dihydropyridine calcium channel blocker
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does nifedipine work?
Nifedipine blocks calcium entry into arteriolar and coronary smooth muscle, widening arteries and stopping coronary spasm. Its half-life is only about 2 hours and CYP3A4 clears it, so slow-release tablets are used for steady control; the immediate-release capsule gives about four times the swing between peak and trough levels.
Like other dihydropyridine calcium channel blockers: They block L-type (slow) calcium channels, mainly in arteriolar smooth muscle, so less calcium enters, the muscle relaxes and peripheral resistance falls. They act far more on vessels than on heart muscle, so at usual doses they barely depress the heart; instead the fall in pressure can set off a reflex rise in heart rate.
Uses
What is nifedipine used for?
- High blood pressure
- Angina, especially vasospastic (Prinzmetal) angina
- Raynaud's phenomenon
Side effects
Side effects of nifedipine
- Ankle swelling (edema), dose-relatedKnown for
- Flushing and a feeling of heatKnown for
- Gum overgrowth (gingival hyperplasia)Known for
- Headache
- Dizziness and lightheadedness
- Fast heartbeat (tachycardia), palpitations
- Low blood pressure, mainly when starting
- Constipation
- Worse angina or a heart attack on starting (rare)Serious
- Heart failure, mostly with a beta blocker (rare)Serious
- Raised liver enzymes and cholestasis (rare)Serious
- Blistering skin reactions such as Stevens-Johnson (rare)Serious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- CYP3A4 inducers such as phenytoin cut its levels by about 70%; grapefruit juice roughly doubles them.
- Extended-release tablets can rarely block the bowel, especially when the gut is narrowed or moves slowly.
- Taper a beta blocker rather than stopping it suddenly; nifedipine does not prevent withdrawal angina.
Good to know: Immediate-release forms swing blood levels widely, so slow-release forms are used for daily control; the NHS also lists it for Raynaud's.
Remember it
A way to remember it
DHP
- D
- Dilated arteries
- H
- Headache and flushing
- P
- Puffy ankles
The class's own initials: they dilate arteries, and that dilation brings headache, flushing and swollen ankles.
Written for biofideX
Its name
-dipine means dihydropyridine calcium channel blocker
Marks nifedipine relatives such as amlodipine. Verapamil (-pamil) and diltiazem (-tiazem) block calcium channels too but are not dihydropyridines.
- Every drug name stem
Its class
Dihydropyridine calcium channel blockers
Other dihydropyridine calcium channel blockers with a card:
Easily mixed up with non-dihydropyridine calcium channel blockers.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Blood pressure
Nifedipine is one of 27 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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