WHEN the Olympic Games" were held in Barcelona four years ago, five athletes tested positive for drugs. Irish 5,000 metres runner Marie McMahon's positive test for "taking two painkillers" brought the number of positive tests in Atlanta `96 to six.

The most serious breaches have involved the use of bromantan, a stimulant. Russian swimmers Andrey Korneyev and Nina Zhivaaevskaya, their compatriot Greeo Roman wrestler Zafar Gulyov and Lithuanian cyclist Bita Razmaite all tested positive for bromantan, which is not included on the International Olympic Committee (IOC) list, but is covered under the category of "related substances" as it is considered a psycho stimulant.

Bromantan, a drug designed for athletes, acts on the central nervous system by affecting the way the brain uses dopamine, a compound produced by the body. It works in two surges when taken by mouth, its greatest effects come after two toe three and six to seven hours, while other research found it reduces fatigue boosts the immune system and helps the body tolerate high temperatures.

However, the Russians argue that bromantan is not a stimulant and have appealed the cases of Korneyev (swimming bronze) and Gulyova (grecoroman wrestling team gold medalist) to the Court of Arbitration for Sport, which is being used at the Olympic Games for the first time.

The IOC revoked the credentials of the Lithuanian cycling coach Boris Vasilyev after .woman cyclist Razmaite tested positive for bromantan, while team doctor Vitaly Slionssarenko has been excluded from all Olympic competitions or qualifying events until the 2000 Games in Sydney.

By contrast, McMahon's positive test for using painkillers appears to be far more innocent. And the 21 year old Clare middle distance runner can perhaps, take some solace from the IOC's handling of Cuban, Estela Rodnguez, who was the first athlete to test `positive at' Atlanta `96.

Rodriguez tested positive for using furosemide, a diuretic. However, the Cuban received only a reprimand and was allowed to keep the silver medal which she won in the judo. Although diuretics have been known to hide the presence of steroids and other performance enhancing drugs, the Olympic medical commission found no. traces of such drugs and decided on a reprimand in Rodriguez's case.

That decision in contrast to the handling of those using bromantan showed flexibility among IOC officials and McMahon will be hoping for similar leniency when the process is complete.