A 25-year-old heroin user presents in opioid withdrawal with lacrimation, rhinorrhoea, yawning, piloerection, mydriasis, and diarrhoea scoring 24 on COWS. He requests medication. Which agent specifically addresses the noradrenergic-mediated symptoms of opioid withdrawal?
- A Methadone (full opioid agonist)
- B Clonidine (alpha-2 adrenergic agonist) ✓
- C Buprenorphine (partial opioid agonist)
- D Naltrexone (opioid antagonist)
Explanation
The autonomic symptoms of opioid withdrawal — lacrimation, rhinorrhoea, piloerection, diaphoresis, diarrhoea, and tachycardia — are primarily mediated by rebound hyperactivity of the locus coeruleus (noradrenergic system), which is normally inhibited by opioids via mu-receptor activation. Clonidine, an alpha-2 agonist, suppresses locus coeruleus firing and attenuates these noradrenergic withdrawal symptoms. It does NOT address opioid craving, mood symptoms, or myalgia. Methadone and buprenorphine act at opioid receptors to suppress both autonomic and subjective withdrawal comprehensively. Naltrexone is used for relapse prevention after detoxification, not acute withdrawal management (it would precipitate severe withdrawal).
Reference: Kaplan & Sadock's Synopsis of Psychiatry, 11th ed.
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Written and medically reviewed by the StethoPrep medical team.