Emotionally unstable patients or history of narcotic abuse. Physical dependence. Avoid abrupt discontinuation & prolonged use. Head injury & increased intracranial pressure; bradycardia. Impaired resp, renal or hepatic function. Patients w/ MI & to undergo surgery of the biliary tract. May impair mental or physical abilities required to perform potentially dangerous tasks eg, driving or operating machinery. Women delivering premature infants. Pregnancy. Childn & neonate.