Читать книгу Practical Cardiovascular Medicine - Elias B. Hanna - Страница 200

1 Non-dihydropyridines (non-DHPs) decrease cardiac inotropism and chronotropism and have a vasodilatory effect (afterload reduction). Also, they dilate the coronary arteries.Examples: diltiazem and verapamil. Verapamil has more negative inotropic effect and slightly more AV and SA nodal depressant effect than diltiazem.Non-DHPs are contraindicated in bradycardia or systolic HF. Avoid non-DHPs, particularly verapamil, in combination with a β-blocker. Diltiazem may be combined with a β-blocker in rate-uncontrolled AF.Doses: diltiazem 30–90 mg TID–QID, diltiazem ER 120–480 mg Qday; verapamil 80–120 mg TID–QID, verapamil ER 180–480 mg/d.

2 Dihydropyridines (DHPs) are more pure and powerful vasodilators than non-DHPs, with minimal ino- and chronotropic effects.Only the long-acting formulations are used. Short-acting DHPs may cause reflex tachycardia, which leads to ischemia.DHPs are not contraindicated in bradycardia or HF, except for nifedipine which has some negative inotropic effect and is preferably avoided in HF; other DHPs have minimal to no negative inotropic effects.In contrast to non-DHPs, DHPs are preferably combined with a β-blocker to counteract any potential reflex tachycardia.DHPs are the first-choice antianginal therapy in patients with bradycardia and the second choice in patients already on β-blockers.Examples are amlodipine 2.5-10 mg Qday, felodipine 2.5-10 mg Qday, and nifedipine XL 30-90 mg Qday.