Patients w/ or family history of QT prolongation, electrolyte abnormalities, CHF, bradyarrhythmias, conduction disturbances. Monitor patients w/ history of constipation or signs of subacute intestinal obstruction. Correct hypokalemia & hypomagnesemia prior to administration. Caution when driving or operating machines. End stage renal disease undergoing haemodialysis. Not to be used in pregnancy. Lactation. Childn.