“Big 5” USMLE toxidromes
| Feature | Anticholinergic | Cholinergic | Sympathomimetic | Opioid | Sedative-Hypnotic |
|---|---|---|---|---|---|
| Vitals | ↑HR, ↑Temp | ↓HR, ↓BP | ↑HR, ↑BP, ↑Temp | ↓RR, ↓BP | ↓RR, ↓BP |
| Pupils | Mydriasis | Miosis | Mydriasis | Miosis | Normal |
| Skin | DRY, Flushed | WET | WET | Normal | Normal |
| Mental Status | Agitated delirium | Confused | Agitated, Paranoid | Obtunded | Obtunded |
| Unique | Urinary retention, Ileus | DUMBBELSS, Fasciculations | Seizures | ↓↓Resp depression | Hyporeflexia |
| Causes | Antihistamines, TCAs, Atropine | Organophosphates, Carbamates | Cocaine, Amphetamines | Heroin, Fentanyl | BZDs, Barbiturates, EtOH |
| Antidote | Physostigmine | Atropine + 2-PAM | BZDs (supportive) | Naloxone | Flumazenil (caution) |