Might cause CNS depression. Normeperidine (active metabolite and CNS stimulant) may accumulate and precipitate anxiety, tremors, or seizures (risk increases with renal dysfunction and cumulative dose). Might cause hypotension (use with caution in hypovolemia, cardiovascular disease (including acute MI), or drugs which may exaggerate hypotensive effects (including phenothiazines or general anesthetics)). May obscure diagnosis or clinical course of acute abdominal conditions. Use with caution in adrenal insufficiency, including Addison’s disease. Use with caution in biliary tract dysfunction (acute pancreatitis might cause constriction of sphincter of Oddi). Use with caution in CNS depression or coma. Potential for drug dependency. Tolerance, psychological and physical dependence might occur with prolonged use. Use with extreme caution in head injury, intracranial lesions, or elevated intracranial pressure (exaggerated elevation of intracranial pressure might occur). Use with caution in hepatic disorders, in morbidly obese patients, in prostatic hyperplasia and/or urinary stricture, and in toxic psychoses. Avoid use in renal impairment. Use with caution 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, since critical respiratory depression might occur. Use not recommended in sickle-cell disease (increased risk of normeperidine-induced seizures). Use with caution in supraventricular tachycardias. Use with caution in thyroid dysfunction. Effects may be potentiated when used with other sedative drugs or ethanol. Use with caution in debilitated patients (greater potential for critical respiratory depression). Avoid use in the elderly. Some preparations contain sulfites (might cause allergic reaction). Use not recommended for management of chronic pain. 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.