Pharmacology, Toxicology and Addiction MedicineTier 1Disease (DEADMAN)

Toxidromes - sympathomimetic

Description

Triad: mydriasis + tachycardia/HTN + agitation, plus diaphoresis (wet skin - key discriminator from anticholinergic, which is dry)
+/- hyperthermia, seizures, active bowel sounds (present, unlike anticholinergic)
Causes: cocaine, amphetamines, methamphetamine, MDMA, synthetic cathinones ("bath salts"), caffeine/theophylline overdose; phaeochromocytoma is an endogenous mimic

Epidemiology

Common presentation to ED - recreational stimulant use, often with agitation requiring sedation
Synthetic cathinones - unpredictable potency, more severe agitation/psychosis than classic amphetamines

Aetiopathogenesis

inc synaptic catecholamines - reuptake inhibition (cocaine) and/or inc release (amphetamines)
-> alpha- and beta-adrenergic overstimulation centrally and peripherally

Diagnosis

Clinical - distinguish from anticholinergic by moist skin + present bowel sounds (anticholinergic = dry, absent bowel sounds)
ECG - arrhythmia, ischaemia
CK - rhabdomyolysis; troponin if chest pain (cocaine-associated ACS)

Management

Benzodiazepines first-line for agitation, HTN and tachycardia - treats the sympathetic drive at its source
Avoid unopposed beta-blockade in cocaine toxicity - unopposed alpha stimulation -> paradoxical HTN/coronary vasospasm
- Cocaine chest pain: benzodiazepines +/- nitrates +/- phentolamine
Active cooling for hyperthermia
IV fluids + standard rhabdomyolysis management if CK raised

Associations

Cocaine - MI (vasospasm + thrombosis), aortic dissection, intracranial haemorrhage
MDMA - hyponatraemia (SIADH + excess water intake), serotonin syndrome, hepatotoxicity
Methamphetamine - cardiomyopathy with chronic use, psychosis, severe dental decay ("meth mouth")

Natural history & complications

Hyperthermia + rhabdomyolysis + DIC = fatal triad in severe toxicity
Agitation typically resolves over hours with adequate sedation
Chronic use -> cardiomyopathy, persisting psychosis, vascular disease

6 more sections, plus exam facts

Premium unlocks every note across every specialty, and the full exam fact library behind it.

Get premium access