MAY POTENTIATE SYSTEMIC TOXICITY OF OTHER AMIDE LOCAL ANAESTHETICS, LIGNOCAINE AND MEPIVACAINE. CLEARANCE REDUCED WITH CIMETIDINE, PROPRANOLOL AND RANITIDINE . CONCURRENT ADMINISTRATION WITH ANTIARRHYTHMICS, BETABLOCKERS & I.V. PROPRANOLOL REDUCED CLEARANCE OF BUPIVACAINE BY 35% LEADING TO INCREASED CHANCES OF TOXICITY. PHENYTOIN MAY INCREASED RISK OF MYOCARDIAL DEPRESSION. LONG TERM ADMINISTRATION OF PHENYTOIN MAY INCREASE DOSAGE REQUIREMENT OF LIGNOCAIN. LIGNOCAIN MAY COMPETITIVELY ENHANCE THE NEUROMUSCULAR BLOCKING ACTIVITY OF SUXOMETHONIUM. HYPOKALEMIA PRODUCED BY ADMINISTRATION OF ACETAZOLAMIDE, LOOP DIURETICS & THIAZIDE DIURETICS ANTAGONISES THE EFFECT OF LIGNOCAIN. HISTORY OF LIGNOCAIN TOXICITY WHEN USED WITH MAXILETINE; HEART FAILURE, CARDIAC ARREST & SEIZURE WITH AMIODARONE & TOCAINIDE USE ; DELIRIUM WITH PROCAINAMIDE USE ARE THERE IN THE LITERATURE.