Which of the following is NOT a common side effect of opioid medications?

Opioids characteristically cause: (1) constipation (via mu-receptor activation in the GI tract, reducing peristalsis - does NOT develop tolerance); (2) nausea and vomiting (via activation of the chemoreceptor trigger zone); (3) respiratory depression (the most dangerous adverse effect, via mu-receptors in the brainstem); (4) euphoria and sedation; (5) miosis (pinpoint pupils); (6) urinary retention; and (7) xerostomia. Opioids are NOT associated with causing drug-induced fever (pyrexia). In fact, some opioids may slightly lower body temperature. Fever in an opioid-using patient should prompt investigation for infection.