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Opioid use disorder
Opioid toxicity is recognised by a triad — pinpoint pupils, respiratory depression and reduced consciousness — and treated with naloxone; opioid withdrawal is not life-threatening in a healthy adult, and the treatment that saves lives in the long term is maintenance with methadone or buprenorphine.
Why it matters in the exam
Exam questions present an unconscious person with slow breathing and pinpoint pupils — and the first step is supporting breathing and naloxone. Remember that naloxone acts for a shorter time than long-acting opioids (methadone) or large amounts of fentanyl, so repeated doses or an infusion and observation may be needed. In a dependent patient start with a low dose and increase gradually, so as not to provoke acute withdrawal, and give the patient and family take-home naloxone.
The withdrawal syndrome includes dilated pupils, yawning, tearing and runny nose, piloerection, diarrhoea, muscle and abdominal pain and anxiety. Treatment is buprenorphine — started only when there is moderate withdrawal (on the COWS scale), otherwise it precipitates withdrawal itself — or methadone (which prolongs the QT), and for symptoms clonidine or lofexidine. Maintenance with methadone or buprenorphine reduces mortality and is better than detoxification alone. Long-acting naltrexone suits only after 7–10 days without opioids. In pregnancy treatment is with methadone or buprenorphine and not detoxification, because detoxification raises the risk of relapse and harm to the fetus; the newborn may develop a withdrawal syndrome and is observed.
Key points
- Toxicity: pinpoint pupils, respiratory depression, reduced consciousness → naloxone.
- Naloxone is short-acting — observation and repeated doses.
- Withdrawal: dilated pupils, yawning, runny nose, diarrhoea; not life-threatening in a healthy adult.
- Maintenance with methadone or buprenorphine reduces mortality.
- Pregnancy: methadone or buprenorphine, not detoxification.
Summary table
| Situation | Signs | Treatment | Exam notes |
|---|---|---|---|
| Toxicity | Pinpoint pupils, slow breathing, reduced consciousness | Ventilation and naloxone (IV, IM or intranasal); repeat doses as needed | Naloxone is shorter-acting than long-acting opioids — observe |
| Withdrawal | Dilated pupils, yawning, tearing, runny nose, piloerection, diarrhoea, pain | Buprenorphine or methadone; clonidine or lofexidine for symptoms | Usually not life-threatening in a healthy adult |
| Starting buprenorphine | Moderate withdrawal on the COWS scale | Buprenorphine in rising doses | Starting too early → precipitated withdrawal |
| Maintenance treatment | Established use disorder | Long-term methadone or buprenorphine | Reduces mortality; methadone prolongs the QT |
| Naltrexone | After 7–10 days without opioids | Long-acting injectable naltrexone | Given too early → acute withdrawal |
| Pregnancy | Opioid use in pregnancy | Methadone or buprenorphine; not detoxification | Neonatal withdrawal syndrome — observation |
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Sources
- ASAM National Practice Guideline for the Treatment of Opioid Use Disorder, 2020 focused update — Pharmacotherapy; overdose
- WHO guidelines, 2009, with later WHO guidance — Psychosocially assisted pharmacological treatment of opioid dependence
- ACOG Committee Opinion No. 711, 2017 — Opioid Use and Opioid Use Disorder in Pregnancy
- Kaplan and Sadock's Synopsis of Psychiatry, 12th edition (2021) — Opioid-Related Disorders
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.