?-Blockers in Hypertension: A Reassessment of the Benefit of Combined ?-/?-Blockade

Clinical updates on carvedilol: a first choice beta-blocker in the treatment of cardiovascular diseases

IMPORTANCE OF THE FIELD

Carvedilol, a non-selective beta-blocker, has recently drawn attention because of its therapeutic benefits over other prescribed analogues for the treatment of cardiovascular diseases (CVDs).

AREAS COVERED IN THIS REVIEW

The present review attempts to present the clinical efficacy of carvedilol in comparison to other available beta-blockers. The literature search was carried out in three electronic databases (Unbound Medline, Pubmed and Sciencedirect) and internet search engines (Scirus and Google Scholar) without time constraints to ensure maximum literature coverage.

WHAT THE READER WILL GAIN

A relatively large number of comparative studies have revealed that carvedilol has advantage over traditional beta-blockers with respect to hemodynamic and metabolic effects, due to its unique non-selective alpha-/beta-adrenoceptor affinity. Such results indicate its safe and effective therapeutic application particularly in patients with complicated CVDs, even in pediatric and geriatric patients.

TAKE HOME MESSAGE

The therapeutic profile of carvedilol indicates its suitability for treatment of complicated CVDs than other non-selective beta-blockers. However, there is a limitation in terms of its dose due to its low bioavailability (approximately 25%). Therefore, there is still need for bioavailability enhancement and dose reduction to further improve the therapeutic efficacy of the drug.

Treatment with metoprolol succinate, a selective beta adrenergic blocker, lowers blood pressure without altering insulin sensitivity in diabetic patients

Insulin resistance is a risk factor for cardiovascular disease. Therapies to lower blood pressure should not decrease insulin sensitivity, especially among high-risk patients such as diabetics. This study examined the effect of the beta1-selective adrenergic receptor-blocking agent extended-release metoprolol succinate (ER metoprolol) on insulin sensitivity in type 2 diabetic patients with suboptimal blood pressure control. Diabetic patients with average blood pressure levels >130/85 mm Hg despite antihypertensive therapy had insulin sensitivity quantified by insulin clamp. ER metoprolol was then added to their ongoing therapy. Following 12 weeks of ER metoprolol plus other therapy, the insulin clamp study was repeated. There were no significant changes in measures of insulin sensitivity, plasma lipids, or hemoglobin A1c with use of ER metoprolol. When beta-blocker therapy is considered, it appears that this agent can be used to treat hypertension without adverse effects on insulin sensitivity in patients with type 2 diabetes, at least over the period of time treated.