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'Animal tests...less predicitve than tossing a coin.'

Kathy Archibald

Director of Europeans for Medical Progress

Wrote an article in the Ecologist, 'Animal testing: science or fiction?' exerts from this article were used by Europeans for Medical Progress, an anti-vivisection group on 5/1/2005

'Arthritis drug Vioxx, withdrawn from the global market in September 2004, appeared to be safe and even beneficial to the heart in animals, but caused as many as 140,000 heart attacks and strokes in the US alone. The associate safety director of the US Food and Drug Administration (FDA) described it as the ‘single greatest drug-safety catastrophe in the history of the world’.

Many studies published in the scientific literature comparing drug side effects in humans and animals have found animal tests to be less predictive than tossing a coin. One review of human-animal correlation in drugs that had been withdrawn because of adverse reactions found that animal tests predicted the human side effects only six out of 114 times.

Hundreds of drugs to treat strokes (eg, Cerestat, MaxiPost, Zendra, Lotrafiban, gavestinel, nimodipine, clomethiazole) have been found safe and  effective in animal studies and then injured or killed patients in clinical trials.

Hormone-replacement therapy (HRT), prescribed to many millions of women because it lowered monkeys’ risk of heart disease and stroke, increases women’s risks of these conditions significantly. The chairman of the German Commission on the Safety of Medicines described HRT as ‘the new thalidomide’. In August 2003 The Lancet estimated that HRT had caused 20,000 cases of breast cancer over the past decade in Britain, in addition to many thousands of heart attacks and strokes.


Cigarette smoke, asbestos, arsenic, benzene, alcohol and glass fibres are all safe to ingest, according to animal studies.

Of 22 drugs shown to have been therapeutic in spinal cord injury in animals, not one is effective in humans.

Of 20 compounds known not to cause cancer in humans, 19 do cause cancer in rodents.


Penicillin, the world’s first antibiotic, was delayed for more than 10 years by misleading results from experiments in rabbits, and would have been  shelved forever had it been tested on guinea pigs, which it kills. Sir Alexander Fleming himself said: ‘How fortunate we didn’t have these animal tests in the 1940s, for penicillin would probably never have been granted a licence, and possibly the whole field of antibiotics might never have been realised.’

Thalidomide, the infamous cause of birth defects in more than 10,000 children in the early 1960s, induces birth defects in very few species. Dr James Schardein, the doyen of birth defect studies, says: ‘In approximately 10 strains of rats, 15 strains of mice, 11 breeds of rabbits, 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.’ Ironically, if thalidomide, the drug whose side effects made animal testing obligatory, were assessed exclusively on its results in such tests it would still be passed today.

Even the Handbook of Laboratory Animal Science admits that ‘uncritical reliance on the results of animal tests can be dangerously misleading and has cost the health and lives of tens of thousands of humans’.

However, later in article Archibald admits that some adverse drug reactions are so rare that they will not be picked up until the drug is given to many people… Vioxx worked for 100,000s, but when the numbers were scaled up there were thousands who suffered side effects.

Last edited: 27 August 2014 05:49

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