Propranolol

Name

• Propranolol.

Class of drug

• Beta-1 and beta-2 adrenoceptor antagonist.

Uses

Action

• A beta-adrenoceptor antagonist. It antagonizes beta-1 adrenoceptors, blocking their chronotropic and inotropic effects on the heart, and beta-2 adreoceptors, blocking their vasodilatory actions.
• Highly lipid-soluble and crosses into the central nervous system (CNS). It is rapidly metabolized by the liver (high first-pass effect).
• An effective antihypertensive drug in humans, acting through reducing cardiac output, altering the baroreceptor reflex sensitivity and blocking peripheral adrenoceptors.

Indications

• Management of cardiac arrhythmias    (sinus tachycardia, atrial fibrillation or flutter, supraventricular tachycardia, premature ventricular depolarization), hypertrophic cardiomyopathy or obstructive heart disease.
• Control of the cardiac features of thyrotoxicosis prior to surgery in patients with hyperthyroidism    .
• May be used to control the pulse rate in patients with phaeochromocytoma    ; always use with phenoxybenzamine    for this indication, as beta-blockade without concurrent alpha-blockade may lead to a hypertensive crisis.

Adverse reactions

Other reported reactions

• Bradycardia.
• Impaired AV conduction.
• Myocardial depression.
• Heart failure.
• Syncope.
• Glucose intolerance.
• Bronchospasm.
• Diarrhea.
• Peripheral vasoconstriction.
• Depression and lethargy (the result of propranolol's high lipid-solubility and its penetration into the CNS).
• May reduce glomerular filtration rate and therefore excacerbate any pre-existing renal impairment.