Dihydropyridines

Nifedipine
Amlodipine
Nimodipine

Indications

Hypertension, stable angina, Prinzmetal's angina, Raynaud's phenomenon.

Mechanism

Ca++ channel blocker. Main effect is in reducing peripheral resistance (↓pre-load). Also reduces myocardial contractility (negatively inotropic, ↓work of heart).

How given

Conventional liquid filled capsules should no longer be used. Only use extended release tablets once daily.

Adverse effects

Most are negatively inotropic and worsen heart failure (except amlodipine—PRAISE study). Dependent oedema (10–30%) disappears on lying flat, not affected by diuretics, hypotension, syncope (dose dependent). Headache, flushing.