DAVID Leung (South China Morning Post, August 19) certainly seems to have grasped one argument by me against euthanasia - that the existence of effective medication makes it unnecessary for anyone to die in pain. This point is one which needs to be made, not least to allay public fear. Medical journal articles stress that mitigating the fear of pain is extremely important for its control. Euthanasia advocates often erroneously claim that patients are condemned to excruciating deaths, thus exacerbating the very fear which makes pain control more difficult. To support their claims, they often introduce anecdotal evidence of patients who did not receive necessary pain management. As a solution they suggest euthanasia - or suicide. David Leung uses the story of L. Tomlinson (Post, July 16) to make the same point. Yes, she needs better medication, but, equally important is caring support. He chooses to ignore her own testimony that it was the support of caring friends which helped her away from suicide. Without that, her suffering would indeed have been intolerable. The Voluntary Euthanasia Society which David Leung espouses has two stated criteria for euthanasia practice - the suffering must be ''intolerable'' and the request ''must be voluntary''. Let's look at the evidence from their paradise, Holland, where they claim euthanasia is practised with adequate safeguards. The Remmelink Report commissioned by the Dutch Government revealed some terrifying facts: Only five per cent of cases of euthanasia were for ''intolerable suffering''. Nearly half of the cases were involuntary. Since that report in 1990 there has been a widening of the criteria, not a tightening. For all the vaunted voluntary, pro-choice principles of the euthanasia movement - the plausible ''right to die'' - there is the dark side for so many of the ''pressure to die''. This was the experience of Ann Humphry, second wife of Derek Humphry. They had both co-founded the Right-to-Die Society, Hemlock, in the US. Derek Humphry wrote the suicide manual Final Exit, recommended by David Leung. Mr Humphey had provided the lethal potion for his first wife who was suffering from cancer to ''assist her deliverance''. When Ann, his second wife, developed cancer he abandoned her. She did not, according to him, ''handle her cancer in a satisfactory manner''. Did she want too much to live? Derek Humphry has devoted his life to death. Ann, in her terminal illness, had opportunity to reflect on her own life work. She reported to American Medical News that in Hemlock ''there has been so much emphasis on dying when you have a life-threatening ill-ness, that measures such as providing a supportive environment are overlooked . . .''. That kind of support Ann Humphry did find - not with Hemlock members - but with Pro-lifers. To prohibit killing, in fact, safeguards the doctor-patient relationship of trust. If doctors are given a licence to kill as well as to heal, patients can never be sure under which licence they are operating. This has certainly been the case in Holland where many people are afraid that if they have to go to hospital they will be killed by their doctors. Not groundless fears, unfortunately. Reports of euthanasia being administered to people with diabetes, rheumatism, multiple sclerosis, AIDS and bronchitis and to accident victims, are not uncommon. Reckless, even casual performance of the practice, often without the patient's consent, has been noted. This is corroborated in a book titled Regulating Death, by Carlos Gomez. His research indicated that the official guidelines governing euthanasia in the Netherlands were both unenforced and unenforceable. It is ironic that a practice that is supposed to give greater control to patients has instead given doctors unprecedented power. So much for David Leung's comment that in Holland ''Euthanasia is exceptional but necessary''. Certainly not exceptional. It may, of course be necessary to a creed which is miserly rather than merciful. Dr ISHBEL TALLACH Kwun Tong This correspondence is now closed.