VPT 321: Veterinary Neuropharmacology (2+1)

α and β- adrenergic receptor antagonists

α AND β - ADRENERGIC RECEPTOR ANTAGONIST

Labetolol

• Labetolol at lower doses blocks only β receptors but at higher doses blocks both α and β receptors.
• Though it non selectively blocks β₁ and β₂ receptors, its α- receptor blockade is limited to only α₁-receptors.
• Labetolol produces fall in blood pressure without producing peripheral vasoconstriction.
• Used for treating hypertension. It is also an important experimental tool.