Cocaine toxicity

What are the symptoms of cocaine toxicity?

• Tachycardia

• HTN

• Anxiety

• Seizure

• Tachypnoea

• Dilated pupils

• Sweaty / pale

• Euphoria / energetic

• Agitated

How do you treat cocaine toxicity?

• O2 – if sats are low, 15l high flow

• IM midazolam - for severe HTN / chest pain

• GTN - for chest pain w BP over 90

• Fluids – if hypotensive, 250ml bolus over 60 secs grey cannula  

What are the benefits for GTN in cocaine toxicity?

• Vasodilator = reduced BP = reduces preload

• Relief of coronary spasm from vasodilation

• Reduces pain through improved coronary blood flow + reduced preload = less strain

What are the risks of using GTN in cocaine toxicity?

• Hypotension - vasodilator

• Reflex tachycardia - drop in BP creates auto response to increase HR

• Inferior stemi = severe drops in BP due to right ventricular infarct - worsened by GTN

What are the benefits of midazolam in cocaine toxicity?

• Reduces agitation / anxiety - inhibits CNS stimulation

• Reduces HTN / tachycardia - inhibits CNS stimulation

• Rapid onset

What are the risks of midazolam for cocaine toxicity?

• CNS depressant - enhances GABA in CNS = respiratory depression as brains drive to breathe is reduced = airway obstruction

• Hypotension - CNS depressant + vasodilation

• Paradoxical reaction - from genetics - increasing agitation

• thermoregulation impaired - redistribution of heat to peripheral tissues, dropping core temp

What is the pathophysiology behind cocaine toxicity?

• Binds to dopamine, catecholamine and serotonin transport proteins = inhibits re-uptake.

• Accumulation of dopamine binds to opioid receptors in brain = euphoria.

• Accumulation of catecholamines = overactivity of sympathetic NS = vasoconstriction = tachycardia + HTN.

• Accumulation of serotonin in CNS = excessive stimulation of 5-HT receptors = agitation, mood alterations, hyperthermia.

• Cocaine blocks sodium channels, prolonging depolarisation, causing prolonged QT interval and ventricular abnormalities e.g. Brugada Syndrome.

• Increased myocardial oxygen demand + coronary artery spasm = chest pain+ increased platelet adhesiveness and aggregation causes occlusion and thus myocardial infaction.