Related Experiment Video
Updated: Aug 4, 2026
08:32
Disrupting Reconsolidation of Fear Memory in Humans by a Noradrenergic β-Blocker
Published on: December 18, 2014
Propranolol in hypertension: a dose-response study
British Medical Journal
|July 17, 1976
Summary
Propranolol at 120 mg/day and 240 mg/day effectively reduced blood pressure in hypertensive patients. Lower doses of propranolol (60 mg/day) showed no significant benefit over placebo.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Hypertension is a prevalent cardiovascular condition requiring effective pharmacologic management.
- Beta-blockers, such as propranolol, are commonly used antihypertensive agents.
- Understanding dose-response relationships is crucial for optimizing treatment efficacy and safety.
Purpose of the Study:
- To evaluate the efficacy and safety of different propranolol dosages in treating hypertension.
- To compare the blood pressure-lowering effects of propranolol against a placebo.
- To assess the impact of propranolol on adverse reactions and patient weight.
Main Methods:
- A double-blind, randomized crossover trial was conducted.
- Twenty-four hypertensive outpatients participated in the study.
- Patients received propranolol (60 mg/day, 120 mg/day, 240 mg/day) and placebo for four weeks each.
Main Results:
- Propranolol 60 mg/day did not significantly reduce blood pressure compared to placebo.
- Both propranolol 120 mg/day and 240 mg/day significantly lowered lying blood pressure by approximately 20/10 mm Hg.
- No significant differences were observed in weight changes or adverse reactions across all treatment groups.
Conclusions:
- Higher doses of propranolol (120 mg/day and 240 mg/day) are effective in reducing blood pressure in hypertensive patients.
- The 60 mg/day dose of propranolol is not superior to placebo for blood pressure control.
- Propranolol demonstrated a favorable safety profile with no significant adverse effects or weight gain noted at the studied doses.
Related Concept Videos
01:27Adrenergic Antagonists: Pharmacological Actions of β-Receptor Blockers
β-receptor blockers significantly impact the cardiovascular system by counteracting catecholamine-induced sympathetic responses. These medications decrease heart rate, contractility, and cardiac output, potentially leading to cardiac depression, life-threatening bradycardia, and death. Therapeutically, β-blockers function as mild antihypertensives and are utilized in treating angina pectoris and cardiac arrhythmias. However, nonselective β-blockers inhibit β2-receptors in bronchial smooth...
01:31Adrenergic Antagonists: ɑ and β-Receptor Blockers
Third-generation β-blockers, such as labetalol and carvedilol, represent a significant advancement in managing cardiovascular conditions. Unlike conventional β-blockers, which can induce peripheral vasoconstriction, third-generation drugs block α1 adrenoceptors. This promotes vasodilation through several mechanisms, such as increased nitric oxide production, inhibition of calcium ion entry, opening of potassium ion channels, and antioxidant action. Labetalol, for instance, is clinically...
01:17Antihypertensive Drugs: Action of β1 Blockers
β1-receptors are primarily located in the heart and kidneys. In cardiac myocytes, these receptors interact with neurotransmitters released by the sympathetic nervous system during heightened activity or danger. As a result, β1-receptors get activated, initiating a series of biochemical processes. Excessive activation of beta receptors due to chronic stress can abnormally increase heart rate and contractility, resulting in high blood pressure or hypertension. To counteract this, β1-blockers...
01:28Antihypertensive Drugs: Types of β-Blockers
β receptors are classified into three subclasses: β1, β2, and β3. β1 receptors are primarily located in the heart and kidneys. When they get activated, they increase heart rate, contractility, and renin release. This process enhances blood pressure and aids in stress management. In contrast, β2 receptors are situated mainly in the lungs, blood vessels, and skeletal muscles. Upon activation, they trigger smooth muscle relaxation, causing bronchodilation and vasodilation. This widens airways and...
01:23Antihypertensive Drugs: Vasodilators
Vasodilators, primarily affecting the smooth muscles within arterial and venous walls, are commonly used for hypertension treatment. Medications such as minoxidil and hydralazine primarily target arteries and arterioles, while sodium nitroprusside acts on arterioles and venules. Minoxidil, functioning as a prodrug, is metabolized by hepatic sulfotransferase into its active form, minoxidil sulfate, after oral administration. This metabolite binds to the sulfonylurea receptor (SUR) component of...
01:22Heart Failure Drugs: β-Blockers
β-adrenergic antagonists, commonly known as β-blockers, block the effects of sympathetic neurotransmitters such as noradrenaline (NA) and adrenaline (ADR). They have several beneficial effects in heart failure treatment. They reduce heart rate, the force of contraction, and cardiac muscle relaxation. They also slow the atrial-ventricular conduction rate and raise the threshold for arrhythmias. The concentration of β-blockers determines their effects on bronchodilation, vasodilation, and...