Substance Use Disorders
This domain tests recognition of dependence, safe management of withdrawal, and understanding of substitution and harm-reduction approaches. Egyptian practice frequently encounters tramadol, cannabis, alcohol and prescription benzodiazepine misuse, so assessment should always include a detailed substance history and urine screening.
Diagnostic rules
ICD-10 dependence requires three or more of six features within a year: strong compulsion to use, impaired control, withdrawal symptoms, tolerance, salience of use over other activities, and persistent use despite harm. Harmful use means use causing physical or psychological damage without meeting dependence criteria. DSM-5 substance use disorder uses eleven criteria and grades severity: mild at two to three, moderate at four to five, severe at six or more.
Withdrawal and its dangers
Alcohol withdrawal follows a predictable timetable: tremor and autonomic overactivity within 6-24 hours, seizures at 24-72 hours, and delirium tremens at 48-96 hours. Delirium tremens is a medical emergency with substantial mortality. Manage with benzodiazepines titrated to a validated scale such as CIWA-Ar, intravenous fluids, and thiamine before any glucose load to prevent Wernicke encephalopathy (ophthalmoplegia, ataxia, confusion). Untreated Wernicke encephalopathy can progress to Korsakoff syndrome.
Opioid overdose presents with pinpoint pupils, respiratory depression and reduced consciousness; naloxone reverses it. Opioid substitution with methadone or buprenorphine reduces mortality; buprenorphine can precipitate withdrawal if given too soon after a full agonist.
Worked example
A 47-year-old man with a long drinking history is admitted with confusion, tremor and visual hallucinations 72 hours after his last drink. Reasoning: the timing and features indicate delirium tremens rather than alcohol intoxication. Management is a benzodiazepine regimen, thiamine, fluid and electrolyte correction, monitoring for arrhythmia and aspiration, and treatment of any infection or injury, not a standing antipsychotic alone.
Traps that cost marks
Giving glucose before thiamine. Using antipsychotics as the main treatment for delirium tremens. Equating tolerance with dependence. Failing to screen for hepatitis B and C and HIV. Missing dual diagnosis and treating only the psychosis. Forgetting that benzodiazepine withdrawal can cause seizures.