Which sign indicates morphine overdose?

• A. Dilated pupils
• B. Pinpoint pupils
• C. Sweating only
• D. Hypertension

Answer: (B)

Pinpoint pupils are the telltale sign of morphine overdose. Opioids like morphine activate mu receptors in the brainstem and parasympathetic pathways, which leads to excessive pupil constriction (miosis). This constriction is a classic, highly characteristic finding in opioid toxicity and is often accompanied by slowed breathing and reduced consciousness due to respiratory depression. Dilated pupils would suggest different drug effects (sympathetic or anticholinergic), sweating alone isn’t specific for overdose, and hypertension isn’t typical for opioid overdoses, which more commonly involve low blood pressure. So the pinpoint constriction of the pupils best signals morphine overdose.