Enhanced or antagonized hypertensive effect, on carbohydrate metabolism or effect on bronchial β₂ receptors of β₁ & β₂ receptors. Enhanced antihypertensive effects w/ ACEIs, Ca-channel blockers, clonidine & drugs that cause hypotension eg, aldesleukin & general anesth, & NSAIDs. May precipitate bradycardia & heart attack w/ other cardiac depressants eg, antiarrhythmics & rate-limiting Ca channel blockers. Exaggerated hypertensive response & inhibited bronchodilator effects w/ adrenaline. Reduced response on anaphylaxis of adrenaline. Reduced response to insulin & oral hypoglycemic agents in diabetic patients. Reduced absorption w/ Al salts & bile-acid resins eg, colestyramine. Increased metabolism w/ barbiturates & rifampicin. Decreased metabolism w/ cimetidine, erythromycin, fluvoxamine & hydralazine. Decreased hepatic clearance w/ cimetidine & hydralazine.