Metoprolol, propanolol, esmolol, atenolol, timolol, carvedilol

- Decrease SA and AV nodal activity by ↓ cAMP, ↓ Ca²⁺ currents. Suppress abnormal pacemakers by ↓ slope of phase 4.- AV node particularly sensitive – ↑ PR interval. - Esmolol very short acting.

Clinical use:- SVT- Ventricular rate control for atrial fibrillation and atrial flutter.

Adverse effects:- Impotence- Exacerbation of COPD and asthma- Bradycardia, AV block, HF- CNS effects (sedation, sleep alterations)- May mask signs of hypoglycemia- Metoprolol can cause dyslipidemia.- Propanolol can exacerbate vasospasm in Prinzmetal angina.- β-blockers (except the nonselective α- and β-antagonists carvedilol and labetalol) cause unapposed α₁-agonist if given alone for pheochromocytome or cocaine toxicity. - Treat β-blocker overdose with saline, atropine, glucagon.