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Cocaine ODPharmacologyDecr presynaptic uptake of NE, E (energy), dopamine (psycho), 5-HT (happy); also LA that blocks Na channels ( wide QRS); also incr release NE<5% metabolised by methylation in liver to norcocaine (also toxic); 30-50% by cholinesterase in plasma and liver to ecgonine methyl ester (non toxic); rest to benzoylecgonine (non toxic)Incr toxicity if decr plasma cholinesterase activity (poor nutrition, genetic); if ETOH on board, makes cocaethylene (more cardiotoxicity), if on MOAIPeak LevelIN (2/3) onset 3-5mins peak blood 15-30mins DOA 60-120minsINH / IV (1/3) onset 16-60secs peak 3-5mins DOA 20-60minsSymptomsSimilar to amphetaminesCV: vasoC (reflex brady), incr HR, HTN decr BP (late, severe toxicity, due to direct Na blockade); long QTc and QRS, arrhythmias, incr automaticity; cause sudden deathHyperadrenergic cardiac failure (subendocardial contraction band necrosis); myocyte apoptosisMyocardial ischaemia / ACS: usually within 12hrs; incr myocardial O2 demand, incr HR, incr SVR, incr contractility, thrombus formation + atherosclerosis; 50% due to thrombosis, 50% from vasospasm; worse if male and smoker; atherosclerosis found on angiogram in 30%; MI in <2-6% cocaine-related chest pain; highest risk in 1st hour; arrhythmias in <3%Others: Dilated cardiomyopathy; myocarditis; aortic and CA dissectionNS: 40% hallucinations; muscle twitching, seizures (within 2hrs, usually self limiting) mvmt disorders (choreoathetoid, dyskinesia; in 1%; may last several days), dystonic reactions mydriasis; spinal cord infarct, cerebral vasculitis, intracranial abscess; central retinal artery occlusionCVA: due to vasospasm, HTN, ICH, incr plt aggregationRS: pul haem, barotrauma, pneumonitis, asthma, NCPOGI: ischaemic colitis, GI ulceration and bleedingMet: rhabdo and incr T (1/3 get ARF; ? die; 50% presenting to ED have incr CK; unlikely to get complications if initial CK <1000); altered LFTOther: nasal septum perf, rhinorrhoea; miscarriage, placental abruption, IUGR, premIxBloods: U+E, CK, Trop, coag; urinary HbCXR: if resp problemsECG: Wide QRS, long QTc, wide complex arrhythmia, incr/decr HRCT head: if altered LOC or any seizureTreatmentAgitation: benzosSeizures: benzos barbsCV complications: arrhythmia: use MgSO4; if VT occurs after acute phase, likely due to ischaemia; if wide complex tachy, try NaHCO3 to pH >7.5; use cardioversion for VT; lignocaine often not helpful and should be used with caution HTN: benzos, nitrates and nitroprusside (0.1-10mcg/kg/min, starting low) Cooling; aggressive IVF if rhabdo; Note, may be prolonged DOA of suxACS: as normal; angioplasty is trt of choice (only if STE resistant to aggressive non-thrombolytic reperfusion therapy); beware thrombolysis if HTN / ?dissection; use verapamil instead of beta-blockersAvoid: beta-blockers (only use with vasodilator, as may cause unopposed vasoC and cause CA vasospasm via alpha effect) 1A/C antiarrhythmics - prolong QTc antipsychotics (lower seizure threshold, worsen incr T and arrhythmia) beware NM blockade may have prolonged effectDecontaminationNoEliminationNoAntidoteNaHCO3: if cardiotoxicity with wide QRS / decr BP / refractory seizuresBody packersBody stuffer = small amount in poorly prepared bags; body packers = large amounts in good bagsGive PEG until last packet passed then do CT with contrast or barium study; immediate surg consult if any signs of intoxication (agitation, HTN, incr HR); benzos while awaiting packet removal; don’t do endoscopy / colonoscopyWithdrawalIrritability, paranoid delusions, depression; not life threatening ................
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