Amphetamines
This covers amphetamines including ecstasy and MDMA.
This covers specific features of amphetamine toxicity. The general approach to management of a poisoning is covered under Poisoning.
Epidemiology and Risk Factors
Pathophysiology
Aetiology
Clinical Features
Mild:
- Sweating
- Dry mouth
- Anxiety
Severe:
- Serotonin syndrome
- Hypertension
- Supraventricular dysrhythmia
Diagnostic Approach and DDx
Investigations
Bedside:
Laboratory:
- Blood
- UEC
- Hyponatraemia
Water intoxication.
- Hyponatraemia
- UEC
Imaging:
Other:
Management
- Manage agitation with benzodiazepines
This also treats haemodynamic effects and ↓ stroke risk. - Correct residual hypertension once agitation controlled
- Treat concomitant serotonin syndrome
- Prevent rhabdomyolysis
Management of serotonin syndrome is covered under Serotonin Syndrome.
Resuscitation:
Specific therapy:
- Pharmacological
- Procedural
- Physical
- Cooling
Supportive care:
- A
- Intubation may be required for:
- Safety
- To manage sedation
- Intubation may be required for:
- C
- Hypertension control
Once agitation is controlled, consider:- Pure α-antagonist
- Mixed α/β-antagonists for refractory hypertension e.g. Phentolamine.
- GTN/SNP
- Pure α-antagonist
- Hypertension control
- D
- Benzodiazepines
First line for:- Agitation
- Haemodynamic control when agitation still present
- Seizures
- Post-intubation sedation
- Propofol
- Dexmedetomidine
- Benzodiazepines
- E
- Maintain normothermia
- Neuromuscular blockade
- Active cooling
- Maintain normothermia
- F
- Maintain adequate urine output
↓ Risk of rhabdomyolysis-associated AKI.
- Maintain adequate urine output
The hyperthermia of sympathomimetic toxicity is not due to an altered hypothalamic set point - paracetamol is ineffective.
Disposition:
Preventative:
Marginal and Ineffective Therapies
- Isolated β-blockade
Theoretic risk of unopposed alpha stimulation.
Anaesthetic Considerations
Complications
- D
- Haemorrhagic stroke
- F
- Hyponatraemia
- Rhabdomyolysis
Prognosis
Key Studies
References
- Bersten, A. D., & Handy, J. M. (2018). Oh’s Intensive Care Manual. Elsevier Gezondheidszorg.