MEDICAL experts are demanding the Government tighten drug-labelling laws following the tragic case of a 11/2-year-old boy who died after being prescribed at least seven unlabelled medications. While the Government last week said it would seek further ''professional opinion'' before making a decision, the Hongkong Medical Association (HKMA) insisted that to introduce legislation on drug labelling would not benefit the public, because of the dangers of self medication. The association advises private doctors to label their medicines, although there is no requirement for them to do so. But a new survey on the drug history of children attending accident and emergency units in hospitals shows doctors are not heeding the HKMA's advice, with medications ''almost never labelled''. The survey indicates parents take their children to different doctors before taking them to hospital. It also shows: A 10-month old girl was given a total of eight drugs, none of which was labelled, by two doctors. A two-year-old boy who had a fever for three days was given eight drugs, all unlabelled, by two doctors. A nine-month-old boy with a breathing complaint was given 10 different drugs by two doctors. All were unlabelled. Dr Peter Sullivan, a senior lecturer in paediatrics at the Chinese University of Hongkong who conducted the survey, warned that the consequences of allowing private doctors to regulate themselves could be deadly. ''Are we going to wait until there is a whole spate of deaths in Hongkong before we act?'' he said. He described the situation where the second doctor consulted did not know what the first doctor had prescribed as ''glaringly anomalous''. Mr Wan Kwok-wah, chairman of the Government Pharmacists' Association, backed the call to label drugs. He said it was a patient's right to know what drugs he or she was taking, and that it would also facilitate the work of accident and emergency doctors. ''And the fact that Hongkong patients do shop around for doctors increases the need for labelling,'' Mr Wan said. Dr Sullivan, who was also an expert witness at the inquest into the death of 18-month-old Ho Chi-hang, said: ''The survey shows that what has happened to Chi-hang could happen to any other child. It is not a satisfactory state of affairs; it is potentially dangerous''. Chi-hang had taken a number of drugs over a short period, prescribed by different doctors. He was found to have died of bronchopneumonia on May 2 last year. The inquest returned a verdict of death by natural causes. But Dr Sullivan said the fact that the jury recommended drugs be labelled suggested the lack of labelling might have had some part to play in the death. ''It is clear from the list of medicine that over a relatively short period of time Chi-hang was given at least seven drugs capable of producing central nervous system depression. ''None of those doctors knew what the other doctors had given. ''In my view, although there is no way we can absolutely prove that his respiratory system was depressed, we have to seriously consider whether the child did not die of pneumonia as said by the pathologist,'' Dr Sullivan said. Chi-hang's father, Mr Ho Kwok-lam, 38, yesterday supported the call for drugs to be labelled. ''Now that my son is dead there is nothing much we can do. But I think we should listen to the experts, and let patients know what medicine they are taking,'' he said. Mr Ho said his family had perhaps been too eager to see Chi-hang respond to treatment and so had taken him to three doctors. Dr Sullivan, a visiting academic from Britain, suggested it might be out of fear of losing business that private doctors did not advocate drug labelling. ''There is a belief among private practitioners that medicine in Hongkong should not be labelled. I have to ask why. Why should Hongkong be different from the UK, which has a statutory requirement for drugs to be labelled? ''My view is they fear if patients know what they are getting, there is a chance they will buy the medicines themselves and doctors will lose the revenue.'' But the HKMA said if patients were told the names of their medicines it would result in more indiscriminate use, especially as pharmacies and dispensaries already sold prescribed drugs over the counter - without asking questions.