Angiotensin II receptor antagonists in chronic heart failure: where do they fit?

Formulation and evaluation of mucoadhesive buccal films of enalapril maleate

Enalapril maleate is used in the treatment of hypertension and angina pectoris. It shows low bioavailability due to high hepatic first pass metabolism. Hence the present work was undertaken to formulate mucoadhesive buccal films of enalapril maleate with an objective to improve therapeutic efficacy, patient compliance and the bioavailability. In the present study ten formulations of mucoadhesive drug delivery system of enalapril maleate were prepared as buccal films, by solvent casting technique. Sodium carboxymethylcellulose, hydroxylpropylmethylcellulose, hydroxyethylcellulose and polyvinyl pyrrolidone K-90 were used as mucoadhesive polymers. Prepared films were evaluated for their weight, thickness, surface pH, swelling index, drug content uniformity, in vitro residence time, folding endurance in vitro release and permeation studies. Films exhibited controlled release over more than 10 h in permeation studies. It was concluded that the films containing 20 mg of enalapril maleate in sodium carboxymethylcellulose 2% w/v and hydroxyethyl cellulose 2% w/v (formulation F5), showed good swelling, a convenient residence time and promising controlled drug release, thus can be selected for the development of buccal film for effective therapeutic uses.

Complementary and Incremental Mortality Risk Prediction by Cortisol and Aldosterone in Chronic Heart Failure

BACKGROUND

In patients with systolic heart failure, high levels of circulating aldosterone are associated with an adverse prognosis, and mineralocorticoid receptor blockade improves survival. The prognostic significance of cortisol that may also bind and activate the mineralocorticoid receptor in chronic heart failure is unknown.

METHODS AND RESULTS

Serum levels of cortisol and aldosterone were quantified in a prospective cohort study of 294 consecutive patients with chronic heart failure [48% were in New York Heart Association functional class III or IV; 58% had systolic heart failure]. During a median follow-up of 803 days (interquartile range, 314 to 1098), 79 patients died (27.3% mortality rate). Cortisol and aldosterone were independent predictors of increased mortality risk in Cox regression analyses adjusted for age, sex, New York Heart Association functional class, C-reactive protein, N-terminal pro-brain natriuretic peptide, sodium, and hypercholesterolemia. The hazard ratio for highest versus lowest tertile of cortisol was 2.72 [95% confidence interval [CI], 1.38 to 5.36; P=0.004], and the hazard ratio for aldosterone was 2.19 (95% CI, 1.23 to 3.93; P=0.008). Patients with both cortisol and aldosterone levels above the respective medians had a 3.4-fold higher mortality risk compared with subjects with both corticosteroids below the median (95% CI, 1.54 to 7.46; P=0.0001). Addition of cortisol and aldosterone levels to the fully adjusted model significantly improved the discriminatory power [increase in Harrell's C-statistic from 0.80 (95% CI, 0.70 to 0.90) to 0.86 (95% CI, 0.79 to 0.94; P<0.001 for change].

CONCLUSIONS

In patients with chronic heart failure, higher serum levels of both cortisol and aldosterone were independent predictors of increased mortality risk that conferred complementary and incremental prognostic value.

Drug Treatment of Congestive Heart Failure

Congestive heart failure (CHF), a syndrome with several pathologic backgrounds, is associated with a series of neuroendocrine (neurohumoral) processes that are triggered by the underlying problem of cardiac pump failure. Several important pathophysiologic systems are stimulated, including the reninangiotensin-aldosterone system (RAAS), the sympathetic nervous system (SNS), the release of vasopressin from the hypothalamus/pituitary axis, and the release of atrial-brain natriuretic peptides from the heart. These neuroendocrine mechanisms are not only highly relevant from diagnostic and pathophysiologic viewpoints, but are also realistic targets for drug treatment. Over the years, it has become clear that drug treatment of CHF with inotropic agents, aiming at the improvement of pump failure, offers but modest benefit. It appears to be preferable to use drugs to target the neuroendocrine processes, and this approach will be the goal of this review. Accordingly, the following therapeutic principles may be applied: 1. Suppression of the hyperactivity of the RAAS, by means of angiotensin-converting enzyme (ACE) inhibitors or angiotensin type 1-receptor antagonists (AT,-blockers); 2. Antagonism of the effects of aldosterone, by means of spironolactone and (possibly) other aldosterone antagonists; 3. Suppression of the hyperactivity of the SNS by means of f-blockers, and (possibly) centrally acting agents such as clonidine, which cause peripheral sympatho-inhibition; and 4. Vasopressin antagonists. The validity of these various concepts will be the subject of the present review.