A young adult stops using intravenous heroin after daily use for several months. He first notices yawning, lacrimation, rhinorrhoea, and sweating, followed by mydriasis, gooseflesh, abdominal cramps, and diarrhoea. Approximately how long after the last dose did this syndrome begin, and when will it peak?

• A Onset 30 to 60 minutes, peak at 6 hours
• B Onset 6 to 12 hours, peak at 24 to 72 hours ✓
• C Onset 24 to 48 hours, peak at day 5
• D Onset 3 to 5 days, peak in the second week

Explanation

For short-acting opioids such as heroin and morphine, the abstinence syndrome begins 6 to 12 hours after the last dose, peaks at 24 to 72 hours, and largely resolves over 7 to 10 days. The timeline shifts later for long-acting agents: methadone withdrawal typically starts 24 to 48 hours after the last dose and lasts longer, which is the key fact that eliminates option C.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

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Written and medically reviewed by the StethoPrep medical team.