May cause CNS depression. May cause hypotension (use with caution in hypovolemia, cardiovascular disease (including acute myocardial infarction), circulatory shock, or drugs which may exaggerate hypotensive effects (including phenothiazines or general anesthetics)). May cause orthostatic hypotension and syncope in ambulatory patients. Use with caution in hypersensitivity reactions to other phenanthrene derivative opioid agonists (codeine, hydrocodone, hydromorphone, levorphanol, oxycodone, oxymorphone). May cause respiratory depression. May obscure diagnosis or clinical course of acute abdominal conditions. May worsen gastrointestinal ileus due to effects on GI motility. Some dosage forms contraindicated in paralytic ileus. Use with caution in adrenal insufficiency, including Addison’s disease, and in biliary tract dysfunction and acute pancreatitis. Use may cause constriction of sphincter of Oddi, diminishing biliary and pancreatic secretions. Some dosage forms contraindicated in post biliary tract surgery. Use with caution in CNS depression or coma. Potential for drug dependency exists. Tolerance, psychological and physical dependence may occur with prolonged use. Use with extreme caution in head injury, intracranial lesions, or elevated intracranial pressure. Some dosage forms contraindicated with increased intracranial pressure or head trauma. Use with caution in severe hepatic impairment, in morbidly obese patients, in prostatic hyperplasia and/or urinary stricture, in renal impairment, and in pre-existing respiratory compromise (hypoxia and/or hypercapnia), chronic obstructive pulmonary disease or other obstructive pulmonary disease, and kyphoscoliosis or other skeletal disorder which may alter respiratory function (critical respiratory depression may occur). Some dosage forms may be contraindicated in severe respiratory disorders. Use with caution in seizure disorders (may cause seizures if high doses used), and in thyroid dysfunction. Effects may be potentiated when used with other sedative drugs, CNS depressants, antihistamines, psychotropic drugs, or ethanol. Use with caution in the elderly. Infants under 3 months of age more susceptible to respiratory depression. Should not be administered with alcoholic beverages or ethanol-containing products; may disrupt extended-release characteristic of product. Some intravenous preparations contain sulfites which may cause allergic reactions in sulfite-sensitive patients. Concurrent use of agonist/antagonist analgesics may precipitate withdrawal symptoms and/or reduced analgesic efficacy in patients following prolonged therapy with μ-opioid agonists. Abrupt discontinuation following prolonged use may also lead to withdrawal symptoms.