Amphetamine toxicity

Background

Amphetamine
MDMA
Mescaline
Desoxyn tablets – pharmaceutical methamphetamine hydrochloride
Crystal meth – illicit methamphetamine hydrochloride
  • Class of xenobiotics (Substituted amphetamines) based on a common central structure (ethylamine group attached to a phenol ring)
    • All have mixed serotonergic and dopaminergic activity
  • Unlike cocaine, duration of action may be 12hr or longer
    • Time- oral- 30min, inhaled instant
    • hepatic and renal excretion- lasts 6- 24 hrs
    • if tolerance developes- physical exam may yield normal findings
    • desipramine and amantadine can give false positive for urine amphet test
    • hallucinogenic amphetamine derivatives may not show up on tox screen AKA Entactogens- enabling user to touch within

Methamphetamine

  • More combative
  • Delusions of parasites, formication, self-mutilate
  • more dysphoric

MDMA Ecstacy

Sympathomimetic toxicities

Clinical Features

Meth mouth
System Minor or moderate overdose Severe overdose
Cardiovascular
  • Cardiac dysrhythmia
  • Hypertension or hypotension
  • Cardiogenic shock
  • Cerebral hemorrhage
  • Circulatory collapse
Central nervous
system
  • Confusion
  • Hyperreflexia
  • Severe agitation
  • Tremor
  • Acute amphetamine psychosis (e.g., delusions and paranoia)
  • Compulsive and repetitive movement
  • Serotonin syndrome
  • Sympathomimetic toxidrome
Musculoskeletal
  • Myalgia
  • Rhabdomyolysis
Respiratory
  • Rapid breathing
Urinary
Other

Differential Diagnosis

Sympathomimetic toxicities

Drugs of abuse

Evaluation

Diagnosis

Toxidrome Chart

Finding Cholinergic Anticholinergic Sympathomimetic Sympatholytic^ Sedative/Hypnotic
Example Organophosphates TCAs Cocaine Clonidine ETOH
Temp Nl Nl / ↑ Nl / ↑ Nl / ↓ Nl / ↓
RR Variable Nl / ↓ Variable Nl / ↓ Nl / ↓
HR Variable ↑ ↑ (sig) Nl / ↓ Nl / ↓
BP ↑ ↑ ↑ Nl / ↓ Nl / ↓
LOC Nl / Lethargic Nl, agitated, psychotic, comatose Nl, agitated, psychotic Nl, Lethargic, or Comatose Nl, Lethargic, or Comatose
Pupils Variable Mydriatic Mydriatic Nl / Miotic
Motor Fasciculations, Flacid Paralysis  Nl Nl / Agitated Nl
Skin Sweating (sig) Hot, dry Sweating Dry
Lungs Bronchospasm / rhinorrhea Nl Nl Nl
Bowel Sounds Hyperactive (SLUDGE) ↓ / Absent Nl / ↓ Nl / ↓
^Consider Sympatholytic when looking at Sedative OD or someone who doesn't respond to Narcan
Withdrawal from substances have the opposite effect

Management

Disposition

See Also

  • Sympathomimetic Toxicity

References