“Addressing the Challenges of Other (or Unknown) Substance Withdrawal”
Emergency Medicine • Addiction Care • Harm Reduction
Addressing the Challenges of Other (or Unknown) Substance Withdrawal
This practical guide helps clinicians manage patients presenting with withdrawal where the specific substance is unknown. It emphasises safety-first assessment, syndrome-based treatment, targeted investigations and linkage to addiction services.
Why this category matters
Patients may present unconscious, confused, or without reliable history — in settings where toxicology is delayed or unavailable. Treating by syndrome (opioid-like, sedative-hypnotic, stimulant, anticholinergic, serotonergic) and prioritising resuscitation reduces harm while investigations proceed.
Initial assessment — ABC + focused history
- Airway, Breathing, Circulation: treat life‑threatening features first. Give naloxone for suspected opioid respiratory depression without waiting for confirmation.
- Rapid observations: GCS, respiratory rate, oxygen saturation, temperature, heart rate, blood pressure, capillary glucose.
- Exposure & focused exam: look for injection marks, pupil size, diaphoresis, tremor, bowel sounds, skin findings (track marks, burns), focal neurology.
- Collateral & scene information: companions, paramedics, pharmacy/clinic records, labeled containers — even small clues help narrow likely substances.
Recognising syndrome patterns (practical clues)
| Syndrome | Key clinical clues | Immediate focus |
|---|---|---|
| Opioid-like | Pinpoint pupils, respiratory depression, reduced consciousness | Naloxone, airway support, oxygen, monitor for re-sedation |
| Sedative-hypnotic/benzodiazepine | Slurred speech, ataxia, somnolence; withdrawal: tremor, agitation, seizures | Airway support; for withdrawal use benzodiazepine protocols/taper; consider flumazenil only rarely and with caution |
| Alcohol withdrawal | Tremor, autonomic hyperactivity, hallucinations, seizures, delirium tremens | Thiamine, benzodiazepine seizure prevention/taper, monitoring, ICU if severe |
| Stimulant | Tachycardia, hypertension, agitation, hyperthermia, diaphoresis | Cooling, benzodiazepines for agitation, cardiovascular monitoring |
| Anticholinergic | Dry skin, dilated pupils, urinary retention, hyperthermia, delirium | Physostigmine in specialist settings, cooling, benzodiazepines for agitation |
| Serotonergic | Hyperreflexia, clonus, agitation, hyperthermia | Cyproheptadine (when indicated), benzodiazepines, cooling, treat complications |
| Unknown/mixed | Overlapping features, delayed tox screen | Syndrome-based care, broad monitoring, avoid harmful antidote empiricism |
Investigations — essential & targeted
- Immediate: capillary glucose, pulse oximetry, ECG, ABG if respiratory compromise suspected.
- Blood tests: CBC, electrolytes, renal & liver function, CK, coagulation, serum osmolality, ethanol level, blood alcohol panel.
- Toxicology: urine drug screen and serum toxicology where available (interpret clinically — many NPS won’t be detected).
- Other: pregnancy test in females of childbearing age, chest x‑ray if aspiration suspected, CT head for head injury or focal neurology.
General management principles
- Safety first: airway protection, treat seizures, control severe agitation to avoid harm.
- Supportive care: oxygen, IV fluids, correction of electrolytes, monitoring urine output and temperature control.
- Syndrome-based pharmacotherapy: use antidotes when strongly indicated (naloxone for opioids); use benzodiazepines for alcohol/benzo withdrawal and stimulant agitation.
- Avoid dangerous combinations: for example, do not give large benzodiazepine doses to patients with suspected mixed opioid-sedative overdose without monitoring respiratory function.
- Escalation: involve critical care early for refractory or severe cases (status epilepticus, refractory hypoxia, severe autonomic instability).
Specific management notes
Opioid overdose / withdrawal
- Give naloxone IV/IM/IN titrated to restore adequate respiration (repeat or infusion may be needed for long-acting opioids).
- When withdrawal is expected after naloxone, support symptoms and consider opioid agonist therapy referral once stable.
Alcohol & benzodiazepine withdrawal
- Administer thiamine, correct hypoglycaemia if present.
- Symptom-triggered benzodiazepine protocols or fixed-dose tapers; consider ICU for DTs or seizures.
Stimulant toxicity/withdrawal
- Benzodiazepines are first-line for agitation and sympathomimetic effects; manage hyperthermia aggressively.
- Cardiac monitoring for arrhythmia and treatment of hypertensive emergencies as needed.
Anticholinergic & serotonergic syndromes
- Differentiate: anticholinergic (dry, red, warm, mydriasis, decreased bowel sounds) vs serotonergic (wet, hyperreflexia, clonus).
- Physostigmine is specialist-managed for anticholinergic toxicity; cyproheptadine for serotonin syndrome when indicated.
Disposition & follow-up planning
- Admit to observation/ward or ICU based on severity and need for monitoring.
- Provide brief motivational intervention when patient stabilises and link to addiction services for further assessment and treatment.
- Offer harm reduction: naloxone kit for peers/family, safer-use advice, vaccination for BBVs and referral to needle/syringe programs where available.
- Document capacity assessments and arrange substitute decision-makers if needed.
Red flags — urgent actions
- Respiratory depression or arrest — immediate airway, naloxone and critical care involvement.
- Generalised seizures or status epilepticus — give benzodiazepines and escalate to ICU.
- Severe hyperthermia (>40°C), rhabdomyolysis or arrhythmia — aggressive cooling, IV fluids and critical care.
- Unexplained reduced consciousness with focal signs — urgent CT head to exclude structural causes.
Case vignette
Patient: P., 34, found drowsy and shallow breathing after a party; no witnesses to substance used. On arrival: RR 6, pinpoint pupils, SpO₂ 78%.
Actions: airway supported, naloxone 0.4 mg IV given with partial reversal, oxygen and monitoring. Urine toxicology sent, patient observed for recurrent sedation; after stabilisation, brief intervention provided and referral to addiction clinic arranged. Naloxone kit provided to friend on discharge.
தமிழில் — சுருக்கம்
எந்தப் பொருள் காரணமாக வெண்பிழை ஏற்பட்டது தெரியாத போது, முதலில் உயிர்காக்கும் சிகிச்சை (ஆதார், הנשா), பின் அறிகுறி அடிப்படையில் சிகிச்சை மற்றும் பாதுகாப்பு நடவடிக்கைகள் முக்கியம். நிரந்தர சிகிச்சைக்காக போதைபொருள் பழக்கம் சேவைகளுடன் இணைத்தல் அவசியம்.
Key takeaways
- When substance identity is unknown, manage by clinical syndrome and prioritise resuscitation and safety.
- Use naloxone liberally for suspected opioid respiratory depression; benzodiazepines for alcohol/benzo withdrawal and stimulant agitation.
- Conduct targeted investigations but treat clinically — many novel substances will not appear on routine screens.
- Link patients to addiction and harm-reduction services after stabilization; document capacity and involve family/caregivers.