Heart failure, chronic calcium channel blockers

Chronic heart failure is typically managed by reduction in physical activity, low dietary intake of sodium (less than 1500 mg sodium per day), and treatment with vasodilators, diuretics and inotropic agents. Drugs that may precipitate or exacerbate CHF—nonsteroidal antiinflammatory drugs (NSAIDs), alcohol, (3-blockers, calcium channel-blockers and some antiarrhythmic drugs—should be avoided if possible. Patients with CHF complain of dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, fatigue, and dependent edema. 

Amlodipine is a long-acting dihydropyridine calcium channel blocker. It has an adverse effects profile similar to those of other dihydropyridines, but at a lower frequency (1). Along with felodipine (2), but unlike other calcium channel blockers, it may also be safer in severe chronic heart failure when there is concurrent angina or hypertension (3). 

Felodipine is a dihydropyridine derivative with diuretic properties (1). Its diuretic properties are not unique but are shared by other dihydropyridines. Its vasodilator-related adverse effects include flushing, headache, and tachycardia (2,3). Reduced arterial oxygen saturation has been seen in patients given intravenous felodipine for pulmonary hypertension (4,5). Along with amlodipine, but unlike other calcium channel blockers, felodipine may be safer in severe chronic heart failure accompanied by angina or hypertension. 

Eactors involved in precipitating decompensation have been evaluated prospectively in patients admitted to the hospital with heart faUure. ° These studies consistently show that noncompliance with drugs or diet is a common cause of heart failure exacerbation. Eor example, 43% of patients admitted with an acute decompensation of chronic heart failure were assessed as having dietary sodium excess, 34% had excess fluid intake (defined as >2.5 L/day), and about 24% had drug noncompliance that may have contributed to their decompensation (although not necessarily defined as the primary cause of decompensation). Use of inappropriate medications such as antiar-rhythmic agents or calcium channel blockers also was an important precipitant of exacerbations. 

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