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  • Print publication year: 2019
  • Online publication date: July 2019

Chapter L - Chapter

from Drugs: An A–Z Guide


Labetalol is a combined α- and β-adrenoceptor antagonist. The proportion of β-blockade to α-blockade when given orally is 3:1, and 7:1 when given IV. It lowers the blood pressure by blocking α-adrenoceptors in arterioles and thereby reduces the peripheral resistance. Concurrent β-blockade protects the heart from reflex sympathetic drive, normally induced by peripheral vasodilatation.