Practical guidelines for the use of converting enzyme inhibitors in congestive heart failure

Acceptability of perindopril in mild-to-moderate chronic congestive heart failure. Results of a long-term open study in 320 patients

The long-term acceptability of perindopril in mild-to-moderate chronic heart failure (CHF) was evaluated in a multicenter open study. A total of 320 patients with a mean age of 62 +/- 1 years and CHF of New York Heart Association (NYHA) class I (2 patients), II (204 patients), or III (114 patients) were included after a 2-week run-in period during which time vasodilators were stopped and diuretic and/or digoxin therapy stabilized. Perindopril treatment was started at 2 mg, increasing to 4 mg once daily after 2 weeks if supine systolic blood pressure remained > 100 mm Hg. After this dose titration period, follow-up visits were scheduled at monthly intervals for the first 3 months, then at 3-month intervals with a maximum period of follow-up being 30 months. At the time of analysis, mean duration of treatment was 276 days and 208 patients were treated > or = 6 months. Of the 320 patients, 10 (3.1%) died, 9 (2.8%) were withdrawn for worsening heart failure, and 38 (11.9%) for nonfatal adverse events, including cough (2.8%), dizziness or orthostatic discomfort (1.9%), angina pectoris (1.6%), and cutaneous signs (1.3%). Exercise test duration increased from 516 +/- 14 to 659 +/- 19 sec after 6 months of treatment (p < 0.01). At 6 months, 55.6% of patients improved by at least 1 NYHA class. Supine systolic blood pressure decreased slightly from 137 +/- 2 to 132 +/- 1 mm Hg (p < 0.01) and plasma creatinine levels remained stable from 100 +/- 2 to 102 +/- 2 mumol/liter after 6 months of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Tolerability of enalapril in congestive heart failure

This report reviews the tolerability profile of enalapril, an angiotensin-converting enzyme (ACE) inhibitor, in the treatment of patients with congestive heart failure. Data have been collected from 546 patients treated with enalapril for up to 9 months in clinical trials other than the Cooperative North Scandinavian Enalapril Survival Study. Results in patients treated with enalapril (n = 193) or placebo (n = 195) in double-blind, controlled clinical trials show that the incidences of death, serious adverse experiences, and adverse experiences requiring discontinuation of double-blind therapy, as well as the overall incidence of such experiences, were similar in the 2 groups. However, certain adverse experiences that are related to the mechanism of action of ACE inhibitors were seen more often after enalapril than after placebo treatment. Dizziness and hypotension were the most frequent adverse experiences reported in patients with heart failure treated with enalapril. The most frequent laboratory adverse experiences were increases in blood urea nitrogen and serum creatinine levels. hyperkalemia was also seen in patients receiving enalapril. It is possible to identify patients at risk of these experiences before initiating treatment with enalapril and to take certain measures (such as withholding or reducing the dose of diuretic drugs and discontinuing potassium supplements or potassium-sparing diuretic drugs) to reduce the likelihood that hypotension, increases in blood urea nitrogen and serum creatinine levels, or hyperkalemia will occur. Angioedema, a recognized adverse effect of ACE inhibitors, was not seen in the clinical trials reviewed here. Cough , another recognized adverse effect of these agents, was seen infrequently and rarely resulted in the discontinuation of enalapril.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical pharmacokinetics in heart failure. An updated review

Pharmacokinetics is the study of the effect that the body has on drug absorption, distribution, metabolism and excretion. The pharmacokinetics of a specific drug are assessed by the volume of distribution, bioavailability, clearance and elimination half-life. Elimination half-life is directly related to the volume of distribution and inversely related to clearance. Any 1 or more of these parameters may be altered by physiological changes such as ageing, or disease states such as congestive heart failure. Congestive heart failure is associated with hypoperfusion to various organs including the sites of drug clearance, i.e. the liver and kidneys. It also leads to organ congestion as seen in the liver and gut. The main changes in drug pharmacokinetics seen in congestive heart failure are a reduction in the volume of distribution and impairment of clearance. The change in elimination half-life consequently depends on whether both clearance and the apparent volume of distribution change, and the extent of that change. Pharmacokinetic changes are not always predictable in congestive heart failure, but it seems that the net effect of reduction in the volume of distribution and impairment of clearance is that plasma concentrations of drugs are usually higher in patients with congestive heart failure than in healthy subjects. The changes in pharmacokinetics assume importance only in the case of drugs with a narrow therapeutic ratio (e.g. digoxin) and some of the antiarrhythmics such as lignocaine (lidocaine), procainamide and disopyramide. This necessitates reduction in both the loading and maintenance doses. Prolongation of the elimination half-life leads to delay in reaching steady-state, and therefore dose increments must be made more gradually. Plasma concentration measurements of the drugs concerned are a good guide to therapy and help to avoid toxicity. Pharmacokinetic changes are of less importance in the case of drugs with immediate clinical response, e.g. diuretics and intravenous vasodilators such as nitrates and phosphodiesterase inhibitors. The dose in the latter group can be titrated to the desired effect. Not all adverse reactions to drugs that may occur in heart failure are the result of alterations in pharmacokinetics; rather, some may be due to important drug interactions. An interaction may occur directly e.g. reduction of renal clearance of digoxin by captopril and quinidine; or indirectly, e.g. through diuretic-induced hypokalaemia, which exacerbate arrhythmias associated with digoxin and antiarrhythmics such as quinidine and procainamide.