Diltiazem
- Class: Non-dihydropyridine calcium channel blocker
- Used for: high blood pressure and arrhythmia
- Say it: dil-TYE-uh-zem
- Forms: tablet, capsule, injection
Remember the name – DIL → dilate
DILTIAZEM DILATES the vessel and slows the beat — it does both jobs at once.
Unlike amlodipine, it acts on the heart as well as the vessels. That is why it controls rate in atrial fibrillation, and why it must never be stacked on a beta blocker without care.
DILTIAZEM DILATES the vessel and slows the beat — it does both jobs at once.
Unlike amlodipine, it acts on the heart as well as the vessels. That is why it controls rate in atrial fibrillation, and why it must never be stacked on a beta blocker without care.
Mnemonic: -dipines hit the hose; diltiazem and verapamil hit the heart
Dihydropyridines work on vessel walls only. The non-dihydropyridines also act on the heart's rate and conduction, which is why only they are used for rate control.
Dihydropyridines work on vessel walls only. The non-dihydropyridines also act on the heart's rate and conduction, which is why only they are used for rate control.
Side effects
Common: ankle swelling, headache, constipation
Serious: slow heart rate, heart block
Typical dose
120–360 mg daily
Immediate-release is three times daily, modified-release once. The two are not interchangeable.
Check yourself
Why can Diltiazem slow the heart when amlodipine does not?
- It also blocks calcium channels in the heart's conduction system
- It is really a beta blocker
- It is given at a much higher dose
- It blocks sodium channels in the heart
Show answer
A. It also blocks calcium channels in the heart's conduction system
The calcium channels in the AV node and in the vessel wall are not identical, and the two families prefer different ones. Amlodipine is vessel-selective, so it has no useful effect on rate.
See it, don't memorize it
The app has the mechanism comic and a patient case for Diltiazem – plus the name link, the class mnemonic, pronunciation you can hear, and a self-check, for the top 100 drugs. One purchase, no subscription, no account.