May impair ability to drive or operate machinery. Emotionally unstable patients or patients with history of opiate abuse; closely monitor these patients during long-term therapy. Impaired respiration due to other drugs, uraemia, bronchial asthma, severe infection, cyanosis, respiratory obstruction. MI patients who exhibit nausea and vomiting and in those about to undergo biliary tract surgery. Head injury, intracranial lesions or pre-existing increased intracranial pressure. Renal or hepatic impairment. Elderly and debilitated patients. Pregnancy and lactation. Lactation: Insignificant amount distributed in milk; use with caution