Amlodipine
A long-acting dihydropyridine calcium channel blocker used for high blood pressure and angina.
Drug card
- How it works
- Blocking L-type calcium channels in artery walls, so arteries widen
- Used for
- High blood pressure
- Stable and vasospastic angina
- Known for
- Ankle and leg swelling (edema), dose-related
- Flushing
- 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 amlodipine work?
Amlodipine blocks calcium entry into vascular smooth muscle more than into heart muscle. It is absorbed slowly (peak at 6 to 12 hours) and has a half-life of 30 to 50 hours, so it starts gently, sudden drops in pressure are unlikely, and steady levels take 7 to 8 days. The liver metabolizes it extensively.
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 amlodipine used for?
- High blood pressure
- Stable and vasospastic angina
Side effects
Side effects of amlodipine
- Ankle and leg swelling (edema), dose-relatedKnown for
- FlushingKnown for
- Headache
- Dizziness
- Palpitations
- Tiredness
- Sleepiness
- Constipation
- Gum overgrowth (gingival hyperplasia), rare
- Worse angina or a heart attack on starting (rare)Serious
- Jaundice and raised liver enzymes (rare)Serious
- Pancreatitis (rare)Serious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Severe liver impairment: the half-life stretches to about 56 hours, so doses are raised slowly.
- CYP3A4 inhibitors such as diltiazem or ketoconazole raise its levels; watch for low blood pressure and edema.
- Severe aortic stenosis: symptomatic low blood pressure is possible.
Good to know: Its very long half-life gives a slow, steady effect, unlike the 2-hour half-life of nifedipine.
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
Amlodipine 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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