morphine sulfate, an opioid analgesic. ▪ INDICATIONS: It is prescribed for relief of moderate to severe pain, including that from myocardial infarction and dyspnea caused by left heart failure, and as a preanesthetic. ▪ CONTRAINDICATIONS: Drug dependence or known hypersensitivity to this drug prohibits its use. ▪ ADVERSE EFFECTS: Among the more serious adverse effects are increased intracranial pressure, cardiovascular disturbances, respiratory depression, and drug dependence. Nausea, vomiting, constipation, and xerostomia are common.