Penicillin and Animal Research

    The Seattle Post Intelligencer recently ran an excellent series of articles debunking a lot of animal rights myths about medical research. That didn’t stop one eighth grader at a local school from writing in to claim that penicillin kills guinea pigs. This claim is straight off of fact sheets (they should call them false sheets) by PETA and other groups. In a fact sheet titled “Drug Testing: Pain, Not Gain,” PETA claims that:

Penicillin would not be in use today if it had been tested on guinea pigs–common laboratory subjects–because penicillin kills guinea pigs.

    PETA doesn’t bother to cite the source of this claim (surprise), but it is actually based on a rather bizarre misreading of a study that examined the effects of prolonged exposure to very large doses of penicillin which does indeed tend to produce toxicity and death. Similar problems, however, occur with human beings who are exposed to very large doses of penicillin for long periods of time, and for much the same reason — in both the guinea pigs and human beings, the prolonged exposure to penicillin kills micro-organisms in the gut which creates a whole host of other problems.

    Leave it to the animal rights activists to claim that studies showing extremely high doses of penicillin administered for long periods of time can produce toxicity in guinea pigs means “penicillin kills guinea pigs.” They might as well say that if penicillin had been tested in human beings it never would have been approved because “penicillin harms human beings.”

    But the interesting thing, it turns out, is that penicillin was largely ignored for many decades after its initial discovery because it didn’t appear to have any beneficial effect in human beings. Only tests done in the first half of the century with mice finally convinced medical researchers that penicillin might have some broad benefits worth exploring.

    Dr. Robert Speth wrote a letter-to-the-editor outlining of the Seattle Post Intelligencer outlining the strange winding path that penicillin took and the crucial role of animal tests, which he has graciously permitted me to reprint:

Animals: Penicillin’s Success Came From Tests on Rats

By Robert Speth

    The animal rights movement has made schoolchildren primary targets of their
anti-research propaganda. The letter (May 14) from Victoria Wilkins, an
eighth-grader at Eckstein Middle School, is an example of how the animal
rights movement is victimizing children. The letter, which no doubt she took
great pains to write, is founded in the litany of inaccurate information used
by the animal rights movement to disparage animal research.

    While each of the arguments she poses against animal research can be
rebutted, her comment regarding penicillin is so inaccurate as to require
immediate correction.

    When penicillin was discovered in the 1870s, it was tested on humans. Its
effects were so erratic and unpredictable that it was ignored as a drug until
1940 when Sir Howard Florey tested it on eight mice injected with a lethal
dose of bacteria. Only the mice that got penicillin lived. The experiment was
so compelling that it quickly led to the use of penicillin in World War II,
saving thousands of soldiers’ lives.

    Florey used mice because he had so little penicillin he could not test it on
humans. Indeed, attempts to use penicillin in humans after Florey’s discovery
were still inconclusive. But, because the results in mice were so convincing,
Florey and his chemist purified their crude penicillin extract to obtain a
grade that worked reliably in humans.

    When animal rights activists tell children that penicillin kills guinea pigs
and, therefore, “If we had relied on animal research we would not have
penicillin” they are lying to our children.

    That is why teachers must be extremely vigilant with regard to the materials
distributed by animal rights groups for their curriculum. Children’s
schooling should not be a means for the animal rights movement to spread its
false propaganda.

    Dr Speth is Professor of Pharmacology and Neuroscience at the College of Veterinary Medicine, Washington State University, Pullman WA. He is also a charter member and Past-President of the Society for Veterinary Medical Ethics, a Board Member of the National Animal Interest Alliance, an emeritus board member of the Washington Association for Biomedical Research, and a recipient of the Lewis J. Kettel award from Incurably Ill For Animal Research.