The image of cocaine as a "safe party drug" is a myth that must be dispelled, say UK experts, as a study shows the drug is linked to 3% of sudden deaths.
The British Heart Foundation said the findings, published in the European Heart Journal, were a reminder that the drug can have devastating effects.
Although the data comes from south-west Spain, researchers said the results should apply to Europe in general.
They said anyone could suffer the deadly consequences of taking cocaine.
Fotini Rozakeas of the British Heart Foundation said: "The reality is that there are risks every time you use it.
"Cocaine can have devastating effects on the user including heart attacks, life-threatening heart rhythms, strokes and even sudden death.
"The potential deadly consequences from cocaine use can happen to anyone who takes it, even in previously young healthy people with no history of heart disease."
Deadly cocktail
In the study, 21 out of 668 sudden deaths were related to cocaine use and all of these occurred in men aged between 21 and 45.
Most involved problems with the heart and the majority of the men were also smokers and had been drinking alcohol at the same time as taking cocaine.
Lead researcher Dr Joaquin Lucena, of the Institute of Legal Medicine in Seville, said these habits added up to a lethal cocktail for the heart.
He said: "Our findings show that cocaine use causes adverse changes to the heart and arteries that then lead to sudden death."
His teams looked at post-mortem reports and investigated all the circumstances surrounding sudden deaths in Seville between 2003 and 2006.
Their findings suggested any amount of the drug could be toxic.
"Some patients have poor outcomes with relatively low blood concentrations, whereas others tolerate large quantities without consequences," they told the European Heart Journal.