Blood chemical counters cocaine

Cocaine can cause heart attacks

A chemical found in the blood of cocaine users could one day help counter the drug's potentially lethal side effects.

Misuse of cocaine can result in heart attacks and other dangerous side effects.

This is because the drug disrupts the transmission of signals from one nerve cell to another.

With substantial numbers of people using the drug it is a public health problem

Dr John Marsden

Finding drugs to counter cocaine poisoning has proved to be very difficult.

But New Scientist magazine reports that a team from Cornell University in New York has discovered a promising candidate - in the bodies of cocaine users themselves.

They found that ecgonine methyl ester (EME), a non-toxic breakdown product of cocaine, can reverse the drug's effects.

In test-tube experiments, synthetic EME completely blocked the drug's effect on the receptor of the nerve cells.

No side effects

The chemical binds to the same receptor, but not in the same way as cocaine. Therefore it does not produce the same dangerous side effects.

Researcher Dr George Hess told BBC News Online: "Cocaine inhibits the action of the nicotinic acetylcholine receptor, and other proteins that are essential for the function of the nervous system.

"These proteins lie at the junction between nerve cells in the brain, and between nerve and muscle cells, including heart cells.

"The compounds we identified prevent inhibition of the receptor at the time they are given.

"So far we have looked at the process only in vitro, that is with cells in a culture dish. The next step is to look at the effect of the compounds in vivo."

Many users

Dr John Marsden, of the National Addiction Centre, said the British Crime Survey 2000 showed that 480,000 people a year in the UK were using cocaine.

He told BBC News Online: "With substantial numbers of people using the drug it is a public health problem, so any study that looks at ways to reduce the risk is a good thing.

"My sense is that we have an interesting finding from the basic science community that may encourage researchers to see if a cocaine antagonist (a drug that essentially reverses its effects) could be found to help in the treatment of people who experience cocaine induced cardiovascular crisis.

"This would indeed be a great benefit since no cocaine antagonist has been identified."

Such a drug, naloxone, is used successfully to reverse the effects of heroin overdose.

Aidan Gray, of Coca, an organisation that works with drug treatment agencies, said anything that would potentially reduce harm to crack and cocaine users would be welcome.

He said: "If this reduced fatalities and therefore pressure on the medical system it would be good.

"Maybe reducing some of the harm associated with the drug is not such a good way to get people off it, but a lot of people are not aware of the cardiovascular risks anyway - you can have a heart attack from your first line of cocaine."

A spokeswoman for the charity DrugScope said: "Any medical discovery that may prevent serious harm and even death associated with drug use is to be warmly welcomed.

"DrugScope also feels it is very important that those who may be considering taking potentially damaging substances are fully aware of all the risks associated with its use."