Substance Use and Addictive Disorders
What this domain tests
This domain tests the DSM-5 substance use disorder criteria and severity bands, withdrawal timelines and their emergencies, and substitution treatments. Regional patterns - tramadol, pregabalin, khat, synthetic cannabinoids - appear in local vignettes.
Core rules and concepts
- DSM-5 SUD: eleven criteria over twelve months; two to three = mild, four to five = moderate, six or more = severe. Tolerance and withdrawal alone, in a patient taking prescribed medication as directed, do not constitute a disorder.
- Alcohol withdrawal timeline: tremor from 6–24 hours, seizures at 12–48 hours, delirium tremens at 48–96 hours. Manage with benzodiazepines guided by CIWA-Ar, plus parenteral thiamine before any glucose load; untreated Wernicke encephalopathy (ophthalmoplegia, ataxia, confusion) can progress to Korsakoff syndrome.
- Opioid: methadone or buprenorphine substitution; naloxone reverses overdose. Alcohol relapse prevention: naltrexone, acamprosate, or supervised disulfiram.
- Benzodiazepine dependence: taper gradually; abrupt cessation risks seizures and delirium.
- Regional agents: tramadol (seizure and serotonin risk), pregabalin, khat (cathinone), synthetic cannabinoids.
Worked example
A 45-year-old presents 36 hours after his last drink with tremor, pulse 120, sweating and visual hallucinations but no seizure. This is alcohol withdrawal with autonomic hyperactivity and perceptual disturbance; management is CIWA-Ar-guided benzodiazepine, thiamine, fluids and electrolyte correction, with a delirium review.
Traps that cost marks
- Equating withdrawal with dependence.
- Giving glucose before thiamine.
- Prescribing disulfiram to an impulsive patient who may drink.
- Missing Wernicke because the patient is "just drunk".