Those who use animals as inexact substitutes always encounter problems of extrapolation to humans, often with grave consequences. The deaths of five human subjects following "successful" tests of a hepatitis drug on dogs is the latest example. Overall, of 198 drugs marketed during the decade 1976- 85, more than half (102) were so much more toxic than premarket animal and limited human trials had indicated that they had to be relabeled or withdrawn.
Similarly, of 25 drugs that appeared to treat strokes in rodents, not a single one worked in people. Millions of dollars, years of effort, and hundreds of animals were lost for nothing.
It is time to stop cheerleading for this expensive and gruesome activity and to start rolling up our sleeves to replace animal experiments with nonanimal models.
NEAL D. BARNARD
President, Physicians Committee for Responsible Medicine
Washington, D.C.
