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Hemodynamic effects of combined beta-adrenoceptor blockade and precapillary vasodilatation in hypertension
Insights
Carvedilol effectively lowers blood pressure in patients with essential hypertension. This new compound offers an attractive hemodynamic profile, showing benefits in both acute and prolonged treatment for hypertension.
Area of Science:
- Pharmacology
- Cardiovascular Medicine
- Hypertension Research
Background:
- Carvedilol is a novel compound combining nonselective beta-adrenoceptor blockade without intrinsic sympathomimetic activity (ISA) and precapillary vasodilation.
- Essential hypertension remains a significant global health concern requiring effective therapeutic agents.
Purpose of the Study:
- To investigate the acute hemodynamic effects of orally administered carvedilol in patients with essential hypertension.
- To compare the acute and short-term effects of carvedilol with propranolol in essential hypertension patients.
Main Methods:
- Acute hemodynamic effects were assessed using invasive (dye-dilution) and noninvasive (forearm plethysmography) techniques.
- A randomized, double-blind, placebo-controlled trial compared carvedilol (25 mg and 50 mg) with propranolol (80 mg twice daily) in 30 essential hypertension patients.
- Blood pressure, total peripheral resistance (TPR), and forearm resistance were measured.
Main Results:
- Carvedilol significantly reduced systolic and diastolic blood pressure in all studied groups (p < 0.05 - 0.001).
- Acute administration of carvedilol (50 mg) reduced forearm resistance by 16% (p < 0.05), while propranolol caused a significant increase.
- After 4 weeks, both carvedilol and propranolol significantly reduced blood pressure similarly, but carvedilol did not reduce blood flow, unlike propranolol.
Conclusions:
- Oral carvedilol demonstrates a useful antihypertensive effect, both acutely and during prolonged treatment.
- Carvedilol possesses an attractive hemodynamic profile, offering vasodilation in addition to beta-blockade.
- Carvedilol presents a favorable alternative for managing essential hypertension compared to traditional beta-blockers like propranolol.
Abstract:
Carvedilol (BM14190) is a new compound with combined properties of nonselective beta-adrenoceptor blockade, devoid of ISA, and precapillary vasodilatation. Its acute hemodynamic effects were studied with invasive technique (dye-dilution using Cardio-Green) in 10 patients taking 25 mg orally and noninvasive (fore-arm plethysmography) in 10 patients taking 25 mg and in 10 patients taking 50 mg orally, all with essential hypertension. Significant reductions of systolic and diastolic blood pressures (p less than 0.05 - 0.001) were observed in all groups. TPR did not change acutely whereas resistance in the fore-arm was reduced by 16% (p less than 0.05). When a comparison with propranolol (80 mgx2) was made in a randomized, double-blind placebo controlled trial comprising 30 patients with essential hypertension, carvedilol acutely reduced blood pressure significantly 13/6 mm Hg (25 mg) and 17/10 mm Hg (50 mg) in contrast to propranolol. Resistance in the fore-arm (plethysmography) fell significantly with carvedilol 50 mg whereas propranolol caused a significant rise. After 4 weeks both compounds had reduced blood pressure significantly and to the same extent. Blood flow was still reduced with propranolol in contrast to the findings with carvedilol. We conclude that carvedilol given orally has a useful antihypertensive effect both acutely and during prolonged treatment. It has an attractive hemodynamic profile.