Letter: Animal testing

Sir: C Ray Greek (Podium, 9 March) appears to be arguing that because testing drugs in animals is not foolproof it is therefore useless, which is absurd.

It is statistically inevitable that occasional adverse effects that were not predicted by animal experiments will occur when drugs are used for the first time in humans, but Greek should address the reverse argument: when tests in animals do result in serious damage or side-effects, especially if these occur in not one but several species, would he then propose that trials in humans should be undertaken anyway? I would be interested to know where he would find informed volunteers willing to participate in such studies, other than in life-threatening or virtually hopeless conditions.

It is more than 35 years since the thalidomide disaster. How many other thalidomides would there have been in the intervening years if new drugs had not been tested on animals first? I do not know the answer (and I doubt that Greek does either), but I suspect hundreds, if not thousands. However imperfect it may be, animal testing is an essential first line of protection for patients against unforeseen harm caused by the introduction of new drugs, and will remain so for the foreseeable future.

GEORGE HAYCOCK

Professor of Paediatrics

Guy's, King's and St Thomas's School of Medicine

Guy's Hospital

London SE1