Occasional cocaine use could promote the formation of blood clots, say researchers from the US.
In a study to determine the effects of cocaine on platelet activation, the researchers found that, even at relatively low doses, cocaine may promote thrombosis and predispose healthy individuals to ischaemic events.
In the randomised, double-blind crossover study, 14 volunteers received a recreational dose of cocaine (2mg/kg intranasally) once and placebo once. Their heart rates and blood chemical responses were then monitored for up to two hours (Heart 2000;83:688). None of the subjects had used cocaine previously. Compared with placebo, cocaine exposure caused an increase in the platelet specific proteins, platelet factor 4 and b-thromboglobulin, indicating that platelet activation had occurred. Formation of platelet-containing microaggregates was also increased following cocaine administration and bleeding time was decreased from 10 to nine minutes. The researchers say the new data could explain why the risk of heart attacks is higher in people who use cocaine. They recommend that the use of platelet inhibitors, such as aspirin, should be considered early in any patient with suspected cocaine-related ischaemia.
In another study, researchers from the National Hospital for Neurology and Neurosurgery in London report on the occurrence of intracerebral haemorrhage in recreational drug users (British Medical Journal 2000;320:1322). The researchers report their treatment of 13 young patients (average age 31 years) who had suffered haemorrhagic stroke following cocaine, amphetamine or ecstasy use. Nine out of the 10 patients who underwent cerebral angiograms had underlying vascular problems, including six with intracranial aneurysm. The researchers recommend that a thorough medical history, focusing on the use of illegal drugs and the toxicological screening of urine and serum, should be part of the evaluation of any young patient with stroke.