Sedative-Hypnotic Toxicology Infographic | Introduction to Medical Pharmacology

Step	Action	Key Points
1 — Airway	Supplemental oxygen; intubate if airway unprotected or ventilation inadequate	Do not await drug identification. Use capnography — pulse oximetry alone is delayed indicator of hypoventilation.
2 — Reversal	Flumazenil in carefully selected cases only	Contraindicated if dependent, prior TCA co-ingestion, seizure history. No reversal agent for barbiturates, Z-drugs, or propofol.
3 — Supportive care	Maintain ventilation, treat hypotension, correct hypothermia	Foundation of management. Monitor for aspiration and rhabdomyolysis.
4 — Phenobarbital	Multiple-dose activated charcoal + urinary alkalinization	Multi-dose activated charcoal (every 4–6 hours) interrupts enterohepatic recirculation. Sodium bicarbonate targets urine pH 7.5–8.0 for ion-trapping.

Co-Ingestant Warning

Isolated benzodiazepine overdose rarely causes fatal respiratory arrest. Opioid co-ingestion produces additive to synergistic respiratory depression — benzodiazepines are co-detected in 30 to 75 percent of opioid overdose fatalities. Mixed overdose is the rule, not the exception, in clinical series.

6–24 Hours

Early Withdrawal

Tremor, anxiety, tachycardia, hypertension, diaphoresis
Mild to moderate CIWA-Ar scores
Oral benzodiazepines typically sufficient

24–48 Hours

Seizure Risk Peak

Generalized tonic-clonic seizures peak in this window
Status epilepticus in ~3% of withdrawing patients
Adequate benzodiazepine or phenobarbital dosing is primary prevention

48–96 Hours

Delirium Tremens

Confusion, agitation, visual hallucinations, hyperthermia
Mortality 5–15% with treatment; >35% untreated
Medical emergency

Agent	Best For	Rationale
Diazepam or chlordiazepoxide	Medically stable patients, no hepatic disease	Self-tapering long half-life. Reduces management complexity. Preferred first-line.
Lorazepam or oxazepam (LOT agents)	Hepatic disease, elderly, high accumulation risk	Glucuronidation only, no active metabolites. Predictable offset. More frequent dosing required.
Phenobarbital loading (IV)	Moderate to severe withdrawal, benzodiazepine-refractory	Directly activates GABA-A channels (bypasses receptor downregulation); inhibits AMPA receptors; 80–120 hour half-life provides sustained coverage.

Mandatory Rule: Thiamine Before Glucose

Give thiamine 500 mg intravenously before or with any glucose-containing fluid in patients with alcohol use disorder. Glucose before thiamine in a thiamine-depleted patient can precipitate Wernicke encephalopathy. This rule is non-negotiable.