HYPOTENSION AND CARDIAC ARREST HAVE BEEN REPORTED WITH THE CONCOMITANT USE OF PROPRANOLOL AND HALOPERIDOL. ALUMINUM HYDROXIDE GEL REDUCES INTESTINAL ABSORPTION OF PROPRANOLOL. CIMETIDINE DECREASE THE HEPATIC METABOLISM OF IT. THEOPHYLLINE CLEARANCE IS REDUCED WHEN USED CONCOMITANTLY WITH PROPRANOLOL
CONCURRENT USE WITH VERAPAMIL & LIGNOCAINE CAUSE BRADYCARDIA, MYOCARDIAL DEPRESSION OR A.V. BLOCK. SEVERE HYPOTENSION & HEART FAILURE OCCUR WHEN USED WITH NIFEDIPINE. ANTIHYPERTENSIVE EFFECT ANTAGONISED BY INDOMETHACIN. CATECHOLAMINE DEPLETING AGENTS LIKE RESERPINE HAS ADDITIVE ACTION OF BETA BLOCKERS LIKE SINUS BRADYCARDIA & HYPOTENSION. EXAGGERATED HYPERTENSIVE RESPONSES HAVE BEEN REPORTED FROM THE COMBINED USE OF BETA- ADRENERGIC ANTAGONISTS AND ALPHA-ADRENERGIC STIMULANTS,INCLUDING THOSE CONTAINED IN PROPRIETARY COLD REMEDIES AND VASOCONSTRICTIVE NASAL DROPS. CAN MASK THE HYPOGLYCAEMIC SYMPTOMS IN DIABETICS WHEN CONCURRENTLY USED WITH ANTIDIABETIC AGENTS. CONCOMITANT ADMINISTRATION OF CHLORTHALIDONE, HYDROCHLORTHIAZIDE, THEOPHYLINE OR DIGOXIN WITH CELIPROLOL MAY REDUCE ITS EXTENT OF ABSORPTION.
ANAESTHETICS THAT CAUSE MYOCARDIAL DEPRESSION, SUCH AS CYCLOPROPANE AND TRICHLOROETHYLENE. THE ANTIHYPERTENSIVE EFFECT OF BETA BLOCKERS MAY BE IMPAIRED BY CONCURRENT ADMINISTRATION OF SOME NSAIDS. BETA BLOCKERS MAY EXACERBATE THE REBOUND HYPERTENSION WHICH CAN FOLLOW THE WITHDRAWAL OF CLONIDINE. IF THE TWO DRUGS ARE COADMINISTERED, THE BETA BLOCKER SHOULD BE WITHDRAWN SEVERAL DAYS BEFORE THE GRADUAL WITHDRAWAL OF CLONIDINE. IF REPLACING CLONIDINE BY BETA-BLOCKER THERAPY, THE INTRODUCTION OF BETA BLOCKERS SHOULD BE DELAYED FOR SEVERAL DAYS AFTER CLONIDINE ADMINISTRATION HAS STOPPED. PHENYTOIN, PHENOBARBITONE, AND RIFAMPIN ACCELERATE PROPRANOLOL CLEARANCE. CHLORPROMAZINE, WHEN USED WITH PROPRANOLOL, RESULTS IN INCREASED PLASMA LEVELS OF BOTH DRUGS. ETHANOL SLOWS THE RATE OF ABSORPTION OF PROPRANOLOL. PINDOLOL HAS BEEN SHOWN TO INCREASE SERUM THIORIDAZINE LEVELS WHEN BOTH DRUGS ARE CO-ADMINISTERED. PINDOLOL LEVELS MAY ALSO BE INCREASED