Substance Intoxication and Withdrawal

Overview & ER Approach - Tox Triage Tactics

• Intoxication: Reversible syndrome due to substance. Withdrawal: Symptoms on cessation/reduction.
• ER Approach:
  • Prioritize ABCDE (Airway, Breathing, Circulation, Disability [GCS, pupils, glucose!], Exposure).
  • History (📌 SAMPLE), exam (vitals, neuro, toxidromes).
  • Investigations: Bedside glucose (critical!), ECG, consider tox screen.
• Tox Triage:
  • Identify toxidromes (e.g., Opioid, Sympathomimetic).
  • Management: Supportive care, decontamination (activated charcoal if <1 hr, specific criteria), antidotes.

⭐ Always consider and rule out hypoglycemia in any patient presenting with altered mental status, especially in suspected intoxication. oka

Alcohol: Intoxication & Withdrawal - The Ethanol Enigma

• Intoxication: Slurred speech, ataxia, nystagmus, impaired judgment, ↓LOC. Supportive care.
• Withdrawal (AWS):
  • Early (6-12h): Tremor, anxiety, insomnia, GI upset, palpitations.
  • Seizures: Generalized tonic-clonic (12-48h).
  • Hallucinosis: Auditory/visual (12-48h), clear sensorium.
  • Delirium Tremens (DTs): (48-96h). Confusion, agitation, fever, tachycardia, HTN. Mortality up to 5%.
  • Assessment: 📌 CIWA-Ar scale (>8-10 needs meds).
  • Treatment: Benzodiazepines (Lorazepam, Diazepam). Thiamine 100mg IV/IM.

    ⭐ Administer IV Thiamine before glucose in suspected Wernicke's encephalopathy to prevent precipitation or worsening of the condition.

• Wernicke's Encephalopathy (WE): Triad: Confusion, ophthalmoplegia (nystagmus, CN VI palsy), ataxia. Thiamine deficiency.

Opioids & Sedatives: Intox & Withdrawal - Nod & Numbness

Opioids:

• Intoxication: 📌 Triad: Miosis (pinpoint pupils), respiratory depression, coma. Other: ↓BP, ↓HR, euphoria. Rx: Naloxone (0.4-2mg IV, repeat PRN).
• Withdrawal: Flu-like symptoms (lacrimation, rhinorrhea, myalgia, N/V/D), mydriasis, piloerection, yawning. Rx: COWS scale, symptomatic (clonidine), buprenorphine/methadone.

Sedative-Hypnotics (Benzodiazepines - BZD, Barbiturates - BARB):

• Intoxication: Drowsiness, slurred speech, ataxia, nystagmus, ↓respiration (esp. BARB or BZD + alcohol).
  • BZD Rx: Flumazenil (0.2mg IV q1min, max 3mg). ⭐

    Flumazenil is generally contraindicated in chronic benzodiazepine users or suspected co-ingestion of tricyclic antidepressants due to the high risk of precipitating intractable seizures.

  • BARB Rx: Supportive, alkalinize urine (phenobarbital), hemodialysis.
• Withdrawal: ⚠️ Life-threatening: Anxiety, insomnia, tremors, ↑HR, ↑BP, sweating, seizures, delirium. Rx: CIWA-B scale, long-acting BZD taper (e.g., diazepam).

Stimulants, Hallucinogens & Toxidromes - Mind-Altering Mayhem

• Stimulants (Cocaine, Amphetamines): Agitation, psychosis, mydriasis, diaphoresis, ↑HR, ↑BP. Manage: Benzodiazepines.
• Hallucinogens:
  • LSD: Visual hallucinations, synesthesia.
  • PCP: Aggression, rotatory nystagmus, ataxia.

  ⭐ Rotatory nystagmus is a pathognomonic sign highly suggestive of Phencyclidine (PCP) intoxication.

  • Cannabis: Euphoria, conjunctival injection.

Key Toxidromes:

High‑Yield Points - ⚡ Biggest Takeaways

• Alcohol withdrawal: Delirium Tremens (DTs) is life-threatening; treat with benzodiazepines (e.g., chlordiazepoxide, lorazepam).
• Opioid withdrawal: Presents with lacrimation, rhinorrhea, yawning, myalgia; naloxone for acute overdose.
• Cocaine/Amphetamine intoxication: Sympathetic overdrive (tachycardia, hypertension, agitation); manage with benzodiazepines.
• Benzodiazepine withdrawal: High risk of seizures; flumazenil for overdose (use with extreme caution).
• Cannabis intoxication: Conjunctival injection, increased appetite, altered perception; withdrawal causes irritability.
• LSD intoxication: Characterized by perceptual distortions, hallucinations, and potential flashbacks; primarily supportive care.
• Methanol poisoning: Causes visual disturbances and anion gap metabolic acidosis; treat with fomepizole or ethanol.