Norepinephrine stimulates the nerves that control the muscles of the heart by binding to the β1- and β2-adrenergic receptors. Carvedilol blocks the binding to those receptors, which both slows the heart rhythm and reduces the force of the heart's pumping. This lowers blood pressure and reduces heart failure. Norepinephrine also binds to the α1-adrenergic receptors on blood vessels, causing them to constrict and raise blood pressure. Carvedilol blocks this binding to the α1-adrenergic receptors too, which also lowers blood pressure.
Relative to other beta blockers, carvedilol has minimal inverse agonist activity (Vanderhoff et al., 1998). This suggests that carvedilol has a reduced negative chronotropic and inotropic effect compared to other beta blockers, which may decrease its potential to worsen symptoms of heart failure. However, to date this theoretical benefit has not been established in clinical trials, and the current version of the ACC/AHA guidelines on congestive heart failure management does not give preference to carvedilol over other beta-blockers.
Carvedilol is indicated in the management of congestive heart failure (CHF), as an adjunct to conventional treatments (ACE inhibitors and diuretics). The use of carvedilol has been shown to provide additional morbidity and mortality benefits in CHF (Packer et al., 2002).
Comparative effectiveness of carvedilol and propranolol on glycemic control and insulin resistance associated with L-thyroxin-induced hyperthyroidism--an experimental study.(Clinical report)
May 01, 2007; Abstract: The present study was undertaken to investigate the effectiveness of adrenergic antagonists Carvedilol and...