In the article on esomeprazole (April 30, 2001, vol. 43, page 36), part of the second sentence in the Adverse Effects paragraph, "or digoxin (Lanoxin, and others)"should be deleted. Esomeprazole may increase serum concentrations of digoxin, probably by increasing absorption.

View Table 3: Some Drug Interactions with DAAs for HCV Infection

The angiotensin-converting enzyme (ACE) inhibitors captopril (Capoten - Squibb) and enalapril (Vasotec - Merck) are now widely used to treat chronic congestive heart failure that has not responded adequately to digitalis and diuretics (Medical Letter, 30:13, Jan 29, 1988). Recently, some cardiologists have debated whether ACE inhibitors should also be used as first-line agents for treatment of this condition (WW Parmley et al, J Am Coll Cardiol, 12:265, July 1988).

Every pharmaceutical drug is a dose-dependent poison. This article describes the clinical presentation and treatment of some dangerous overdoses commonly reported in adults.

The drugs of choice for treatment of common cardiac arrhythmias are listed in Tables 1 and 2. Some drugs are recommended for indications that have not been approved by the FDA.

Spironolactone, an aldosterone receptor antagonist, has been FDA-approved for many years for treatment of edema, hypertension and primary hyperaldosteronism. Recently, it was reported to improve morbidity and mortality in patients with severe heart failure.

Among patients with chronic heart failure, those with a left ventricular ejection fraction (LVEF) ≤40% are considered to have heart failure with reduced ejection fraction (HFrEF). Patients with a LVEF ≥50% are considered to have heart failure with preserved ejection fraction (HFpEF). Those with a LVEF of 41-49% are an intermediate group more similar to patients with HFpEF.

Flecainide (Tambocor -3M Pharmaceuticals), first introduced in 1985 for treatment of ventricular arrhythmias, was recently approved by the US Food and Drug Administration for oral use to prevent supraventricular arrhythmias. The indications for using flecainide to treat ventricular arrhythmias were limited after a controlled trial found that post-myocardial infarction patients with asymptomatic ventricular arrhythmias who took the drug had twice as high a mortality rate as patients who took placebo (DS Echt et al, N Engl Med, 324:781, 1991).

View Table: Mechanisms of Drug Interactions

Carvedilol (Coreg - SmithKline Beecham and Boehringer-Mannheim), a betaadrenergic and alpha-adrenergic blocker approved by the FDA for treatment of hypertension in 1995, but not marketed at that time, has now been approved and marketed for treatment of mild or moderate (NYHA class II or III) heart failure stabilized on other drugs. It is being promoted as an add-on drug that reduces the morbidity and mortality of the disease.