Thalidomide:
There is, however, a major and tragic irony in blaming insufficient animal testing for the disaster: more animal testing would not have prevented the release of thalidomide, since very few species suffer birth defects or other adverse effects in response to the drug. The Office of Health Economics concluded that: “It is unlikely that specific tests in pregnant animals would have given the necessary warning: the right species would probably never have been used.”
http://www.safermedicines.org/pletters/ ... ?year=2012Although the drug was marketed in 1957, reproductive studies on thalidomide in animals were not started until 1961, after the drug's effects on human fetuses had begun to be suspected (MacBride, 1961 and Lenz, 1961, 1962). Initial studies on rats and mice revealed some reproductive abnormalities, notably reduction in litter size due to resorption of fetuses; however, only when the compound was tested in the New Zealand white rabbit did abnormalities similar to those noticed in human babies occur. Studies on monkeys revealed that they were almost as sensitive as humans to the deformative effects of the drug.
http://caat.jhsph.edu/publications/anim ... pter3.htmlIn 1957, soon after launching Contergan (thalidomide) in West Germany, came reports of peripheral neuritis that revealed thalidomide's toxic effects on the nervous system of the user. (5) This is a serious illness which may occur anywhere in the body. For example, it may begin with a prickly feeling in the toes, followed by a sensation of numbness and cold. The numbness spreads often above the ankles, and eventually is followed by severe muscular cramps, weakness of limbs, and a lack of co-ordination. Some of these symptoms improve or disappear when the cause is removed, but much of the damage is irreversible. (6)
Peripheral neuritis does not itself point to reproductive damage, but many scientists would take such an assault on the nervous system as grounds for general suspicion. (7) One such scientist, McCredie reported that the limbs of children with thalidomide malformations show changes analogous to those which can occur in the adult as a consequence of pathological alterations to peripheral nerves. (8) Such a suspicion was suggestive enough to cause Dr Frances Kelsey, the Medical Officer of the Food and Drug Administration, to reject the drug firm's application to market Kevadon (thalidomide) in the United States, because among other reasons, she wasn't satisfied that the drug would be safe to take during pregnancy. Her handwritten note on the original memorandum reads: "This was based on peripheral neuritis symptoms in adults." (9)
The original animal tests by Chemie Grünenthal did not show indications of this unexpected and serious side-effect. (10) Furthermore, in several European countries, including England and Sweden, the licensees of thalidomide carried out their own animal tests, independently from the German firm, and came to the same results as Chemie Grünenthal. (11) If the tests had predicted peripheral neuritis and if the firms acted upon the results in a responsible manner, the drug would not have been released in the first place and a major disaster would have been avoided.
Unfortunately this wasn't the case: "an estimated 10,000 children-but probably many more-born throughout the world as phocomelics, deformed, some with fin-like hands grown directly on the shoulders; with stunted or missing limbs; deformed eyes and ears; ingrown genitals; absence of a lung; a great many of them still-born or dying shortly after birth; parents under shock, mothers gone insane, some driven to infanticide." (12) (Hans Ruesch, medical historian.)
And to illustrate just how criminally neglectful the firms behaved, consider the fact that despite thousands of cases of peripheral neuritis and that a growing number of cases of deformities were being reported the drug firms resisted moves to withdrawal their products. Besides, their resumed animal tests could not duplicate the deformities, so they saw no reason to remove the drug. Only until the evidence was overwhelming did Chemie Grünenthal finally take Contergan off the market. (13) Also, in other countries around the world including Brazil, Italy, Japan, Sweden and Canada drugs containing thalidomide were not withdrawn till a year or longer after Grünenthal's withdrawal of the drug. (14)
As a consequence to the thalidomide tragedy there has been a marked upsurge in the number of animals used in testing of new drugs. Also drugs are now specifically tested on pregnant animals to supposedly safeguard against possible teratogenic effects on the human foetus. Vivisector's claim that if such tests were carried out prior to thalidomide's release, birth deformities in humans would have been discovered. This is of course sheer nonsense. "In pregnant animals, differences in the physiological structure, function and biochemistry of the placenta aggravate the usual differences in metabolism, excretion, distribution and absorption that exist between species and make reliable predictions impossible." (15) (Dr Robert Sharpe, former senior research chemist.)
In fact when the link between human foetal abnormalities and thalidomide was established (through clinical observation), the world-wide explosion of animal testing, using a large range of species, proved very difficult to duplicate the abnormalities. (16) Writing in his book Drugs as Teratogens, J.L. Schardein observes: "In approximately 10 strains of rats, 15 strains of mice, eleven breeds of rabbit, two breeds of dogs, three strains of hamsters, eight species of primates and in other such varied species as cats, armadillos, guinea pigs, swine and ferrets in which thalidomide has been tested teratogenic effects have been induced only occasionally." (17) Eventually after administrating high doses of thalidomide to certain species of rabbit (New Zealand White) and primates could similar abnormalities be found. However researchers pointed out that malformations, like cancer, could occur when practically any substance, including sugar and salt, be given in excessive doses. (16)
All this just reaffirms what many doctors and scientists have been warning for a number of decades-animal experimentation misleads science and any similarity to the human situation is merely a coincidence and cannot be verified until the experiment is repeated on humans. Experimenting on animals is like playing roulette. (18)
http://www.pnc.com.au/~cafmr/online/res ... alid2.htmlGerman-based Gruenenthal has issued its first apology in 50 years, but said the drug's possible side-effects "could not be detected" before it was marketed.
Mr Stock said the company regretted that the potential for thalidomide to affect the development of foetuses "could not be detected by the tests that we and others carried out before it was marketed.
http://www.bbc.co.uk/news/health-19448046Martin Johnson, director of the Thalidomide Trust, told the BBC that the news that the manufacturers were starting to acknowledge responsibility was welcome but they were still trying to perpetuate the myth that no-one could have known of the harm the drug could cause when there was, he said, much evidence that they did know.
http://www.bbc.co.uk/news/health-19443910
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