Makindo Medical Notes.com

Related Subjects: |Hypertension

Always ask about it where it may be relevant e.g. chest pain, haemorrhagic stroke, trauma (people get in fights) Note that with cocaine-induced chest pain that unselected Beta Blockade alone will cause hypertension due to unopposed alpha effects and should be avoided.

About

• Cocaine is a central nervous system stimulant derived from the leaves of the coca plant. The primary effect of cocaine is the blockade of the reuptake of dopamine, serotonin and Noradrenaline [US Norepinephrine] [norepinephrine] thus raising the levels of these substances.
• It is suggested that chronic usage may actually accelerate atherosclerosis. The pleasures of cocaine come from raising dopamine levels in the mesolimbic reward centres.
• Cocaine can be snorted and absorbed into the circulation through rich vascular tissues lining the nose. It causes localised vasoconstriction and eventual damage to the nasal mucosa. It can be smoked or taken intravenously. The last two give a rapid response but a shorter high than snorting. Other methods include rubbing it on the gums or taking small amounts orally. It has also been taken as a suppository. It is still used as a local anaesthetic in some ophthalmic and ENT surgery particularly as it also reduces bleeding.

Clinical

• Cocaine induced chest pain is usually due to spasm and is generally (there are exceptions) not treated with thrombolysis. Patients who take cocaine often do have the coexisting atherosclerotic disease and these areas of disease are actually more prone to spasm. Thrombolysis is generally avoided and indeed there is also a significant risk of intracerebral haemorrhage with cocaine which would also be against risking thrombolysis. If ST-elevation persists then refer for primary PCI using the STEMI pathway. The patient may be given IV nitrates as a prelude to PPCI.
• Hyperthermia is a recognised side effect of cocaine and should be treated with fluids, cooling and dantrolene. Haloperidol [Haldol]and phenothiazines should be avoided as they lower the fit threshold. Try Diazepam.
• Delirium, hyperthermia, arrhythmias, myocardial and cerebral infarction are reported. Management is always ABC and also to remove any residual cocaine from the nostrils. Generally, the toxic effects of cocaine are short-lived and relate to sympathetic stimulation, as in this case with tachycardia, pyrexia and hypertension. Initial treatment of cocaine poisoning involves the intravenous administration of diazepam to control agitation, and cooling measures for hyperthermia. Sedation with diazepam may also be appropriate initial therapy for hypertension and tachycardia in this situation since the excessive sympathetic tone is largely centrally mediated. Control of anxiety and agitation with diazepam, when combined with rapid cooling, may also decrease heat production in hyperthermic patients. If further treatment is required, intravenous nitrate is particularly useful for associated coronary artery spasm.