[Pharmacology of adrenergic beta receptor blockaders]

Betablockers may be classified according to their cardio selectivity, intrinsic sympathomimetic action and direct vasodilating action. All beta blockers reduce renin plasma levels, the effect being inversely proportional to the intrinsic sympathomimetic property. The hypotensive effect is related more to vasodilation than to a decrease in cardiac output. The hypotensive action is mediated by presynaptic beta receptors which normally stimulate noradrenaline secretion by nerve endings. Adverse effects, interaction with other drugs, and effects on risk factors of beta blockers are also reviewed.