5. Adverse effects: Severe respiratory depression can occur and result in death from acute opioid poisoning. A serious effect of the drug is stoppage of respiratory exchange in patients with emphysema or cor pulmonale. [If used in such individuals, respiration must be carefully monitored.] Other effects include vomiting, dysphoria, and histamine-enhanced hypotensive effects. The elevation of intracranial pressure, particularly in head injury, can be serious. Morphine enhances cerebral and spinal ischemia. In benign prostatic hyperplasia, impaired renal function.morphine may cause acute urinary retention. Patients with adrenal insufficiency or myxedema may experience extended and increased effects from the opioids. Morphine should be used cautiously in patients with bronchial asthma, liver failure, or