Cocaine is a classic sympathomimetic, used by the Incas as an appetite suppressant and noted for its analgesic properties we now use it medically as a local anaesthetic (Sodium channel blockade of the nerves). Recreationally it is used as a party drug which can be potentially lethal in overdose. Find out how to investigate and manage the complications.
- Ingestion of >1g is potentially lethal (average line is 20-30mg)
- Life threats include hyperthermia, hypertension, dysrhythmias, ischaemia, seizures, dissections, intracerebral haemorrhage, and cerebral oedema.
- Mainstay of treatment is with benzodiazepines (agitation, hypertension, tachycardia and hyperthermia)
- Treat dysrhythmias with sodium bicarbonate or if refractory lignocaine
- Beta blockers are contraindicated
- Thrombolysis is relatively contraindicated
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The show notes are presented as a ‘show and reveal‘ mini quiz.
- VT is initially treated with 50-100 mmol of sodium bicarbonate. Defibrillation is also used along normal protocols but may not be successful (hence the addition of sodium bicarbonate – )
- Failing the above treatment 1.5mg/kg IV of lignocaine followed by an infusion of 2mg/minute. Those astute pharmacologists will be aware that lignocaine is also a sodium channel blocker. The theory that it acts as a competitive inhibitor to cocaine (and other sodium channel blocking drugs) at a receptor level, it also interacts less with the sodium channel receptors leaving them free to work as a sodium channel.
Resus: As mentioned we would avoid giving beta-blockers in an acute coronary syndrome
…But what would you give?
- Aspirin (and other anti platelets depending on your hospital protocols)
- Calcium channel antagonists
- Coronary angiography +/- stenting
- Severe hypertension
- Intracranial haemorrhage
- Aortic dissection
- Verapamil 5mg IV
- Adenosine 6-12mg IV
- Cardioversion if unstable
- Phentolamine 1mg IV repeated every 5 mins. This drug maybe more familiar to those in the operating theatre during phaeochromocytoma as it is used to control blood pressure. It is a reversible nonselective alpha-adrenergic antagonist. Its primary action is vasodilatation due to alpha 1 blockade.
- A vasodilator infusion such as sodium nitroprusside or glyceryl trinitrate.
- AVOID Beta blockers.
- Hyperthermia needs aggressive management to prevent multi-organ failure.
- This patient will require external cooling via ice packs and cool fluids. This will of course be uncomfortable and elicit shivering in the conscious patient. Therefore they need paralysis, intubation and ventilation.
- CNS: Agitation, Aggression, Psychosis, Myoclonic movements, Seizures, intra-cerebral bleeds and Cerebral oedema.
- CVS: Tachycardia, Dysrhythmias, Acute coronary syndrome, Acute pulmonary oedema, Aortic or Carotid dissection and Ischaemic Colitis
- Other: Hyperthermia, Pneumothorax, Rhabdomyolysis and Pneumomediastinum
- Anaesthetic dose = 1-3mg/kg
- Line of cocaine = 20-30mg
- Potentially lethal = 1g
- Cocaine should be on your list of ‘1-2 pills can kill’ for children.
- CT brain. This should always be strongly considered even when the patient is going to angiogram as it is likely he will get anti coagulated if necessary.
- This child will need to be observed 4 hours post potential ingestion. If they do not develop any symptoms during this time they may be cleared.
- Afonso L. Mohammad T. Thatai D. Crack whips the heart: a review of the cardiovascular toxicity of cocaine. American Journal of Cardiology 2007; 100(6):1040-1043.
- Hatsukami DK, Fischman MW. Crack cocaine and cocaine hydrochloride. Are the differences myth or reality? Journal of the American Medical Association 1996; 276:1580-1588.
- Lange RA, Hillis LD. Cardiovascular Complications of Cocaine Use. New England Journal of Medicine. 2001; 345(5):351-358.
- Shih RD, Hollander JE, Burstein JL et al. Clinical safety of lidocaine in patients with cocaine-associated myocardial infarction. Annals of Emergency Medicine 1995;26:702-706.
- Murray L, Little M, Pascu O, Hoggett K. Toxicology Handbook 3rd Edition. Elsevier 2015. ISBN 9780729542241