Substance Use and Withdrawal
Alcohol, opioids, stimulants and nicotine
Alcohol withdrawal timeline (after the last drink)
| Time | What happens |
|---|---|
| 6–24 h | Tremor, anxiety, sweating, nausea, insomnia, tachycardia and hypertension |
| 12–48 h | Hallucinations (usually with clear consciousness) |
| 6–48 h | Seizures (peak ~24 h) |
| 48–96 h | Delirium tremens: confusion, hallucinations, fever, severe autonomic instability. Can be fatal |
Use CIWA-Ar to score severity; give benzodiazepines (chlordiazepoxide, diazepam, or lorazepam in liver disease) per protocol. Thiamine before glucose (prevents Wernicke's encephalopathy: confusion, ataxia, eye movement problems → Korsakoff: memory loss, confabulation). Seizure precautions; quiet, well-lit room; fluids and electrolytes (Mg²⁺, K⁺).
Alcohol use disorder: long term
- Naltrexone (reduces cravings; not with opioids; liver tests).
- Acamprosate (start after withdrawal; adjust for kidneys).
- Disulfiram: any alcohol (including mouthwash, cough syrup, some sauces) → flushing, vomiting, low BP. Only for motivated patients.
- Mutual support (AA), motivational interviewing; screen with AUDIT; SBIRT.
Opioids
- Overdose: pinpoint pupils, slow breathing, unresponsive → naloxone (available over the counter), rescue breaths/CPR. Fentanyl may need repeat doses; naloxone is still given when xylazine may be present (xylazine also causes sedation and wounds).
- Withdrawal (rarely fatal in adults): yawning, runny nose, tearing, dilated pupils, gooseflesh, cramps, diarrhea, vomiting, anxiety. Score with COWS.
- Medications for opioid use disorder: buprenorphine (start once in withdrawal, or it triggers sudden withdrawal; any DEA-registered prescriber since 2023), methadone (clinic; QT), naltrexone (after 7–10 days opioid-free).
Stimulants (cocaine, methamphetamine)
Intoxication: high BP and HR, hyperthermia, chest pain (MI), paranoia, agitation, seizures → benzodiazepines, cooling. Withdrawal ("crash"): exhaustion, oversleeping, hunger, depression and suicide risk, cravings.
Cannabis
Heavy use can cause cannabinoid hyperemesis syndrome: cyclic vomiting relieved by hot showers.
Nicotine
Combine counseling with medication: varenicline (most effective), nicotine replacement (patch + short-acting form), bupropion. Ask every patient about tobacco and vaping.