Results of a study on sudden death show there is no such thing as safe recreational cocaine use, the researchers said, and suggest the 12 million Europeans who use cocaine are putting their lives at risk.
More than 3 per cent of sudden deaths in Europe are related to cocaine use and many of them are brought on by a "lethal cocktail" of the drug, alcohol and cigarettes, scientists said today.
"The notion that recreational cocaine use is 'safe' should be dispelled, since even small amounts may have catastrophic consequences, including sudden death," said Joaquin Lucena, head of forensic pathology at the Institute of Legal Medicine in Seville, Spain.
Mr Lucena and his team studied sudden deaths in south-west Spain between 2003 and 2006 and found 3.1 percent of them were related to taking cocaine, which had damaged the heart and arteries.
The researchers also found all the cocaine sudden deaths were in men aged between 21 and 45, and 81 per cent of them also smoked, while 76 per cent had also drunk alcohol.
Ethanol, the intoxicating ingredient in alcohol, enhances the high users get from cocaine and softens the subsequent low. But both smoking and alcohol are also linked with heart disease.
"The combination of cocaine with either or both of these habits can be considered as a lethal cocktail that promotes the development of premature heart disease," Mr Lucena wrote in the study, which was published in the European Heart Journal.
Mr Lucena also said he believed his findings could safely be extrapolated to much of the rest of Europe, suggesting cocaine use is a significant public health threat. "Cocaine abuse is a growing public health issue in Europe and we can only monitor its prevalence by performing these detailed autopsies whenever someone dies suddenly," he wrote.
Experts at the Spanish Institute estimate about 12 million Europeans use cocaine - about 3.7 per cent of the total adult population aged 15 to 64. More than 5 per cent of adults in Britain, Spain and Italy say they have taken cocaine at least once in their lives and use is higher among those aged between 15 and 34.
The Irish Heart Foundation said clinical experience in Ireland over the last few years shows that not only does cocaine cause sudden cardiac death, but it is also responsible for an alarming rise in hospital emergency admissions for serious heart attacks.
"Subsequent investigations showed that no underlying heart disease existed in many of the younger patients, which supports the Spanish findings," said IHF medical director Dr Brian Maurer. "At the Irish Heart Foundation we urge everyone, especially young people, to refrain from using cocaine. Even small amounts taken infrequently are dangerous and can result in sudden death or long term disability due to a heart attack."