If testing was directly carried out during clinical trials, companies would be cautious to select the best potential drugs, based on rational designs and after preliminary testing on human tissue and cells. Once sufficient confidence is gained that a drug is proven relatively safe and efficient by using in vitro methods, further proof of safety and efficacy is monitored in volunteers by gradual dosing and careful clinical assessement.
Creating beneficial drugs is a difficult enterprise and drug companies invest more money in marketing than in research and development. If they cannot control innovation, they do influence the choice of consumers. The mission statement of drug companies is to make profits and under the disguise of philantropy, drug companies have become generous contributors to the electoral campaigns of our politicians, who in turn will champion the legislation Big Pharma needs.
The rest of the chemicals tested and washed off is held in secrecy for proprietary reasons, many companies can test the same chemicals or the same drugs. This is called fair competition, which implies more animal testing.
Most side effects, which occur in man cannot be demonstrated, anticipated or avoided by the routine subacute and chronic toxicity experiment. Diseases can take a long time to develop, incubate and are mainly due to environmental factors, aging and little to genetic factors.
For instance, the effectiveness of animal experiments was evaluated by animal experimenters who took six drugs and noted which of the 78 adverse effects (in humans) were detectable in dogs and rats. The undetectable effects (e.g. headaches) were not included in the study. Less that half (46%) were detected in the animals - slightly less than the expected results from flipping a coin. Clin Pharmacol Ther 1962; pp665-672
Of 198 drugs monitored by the FDA, 102 (52%) were re-labelled or withdrawn due to unforeseen effects.
GAO/PEMD-90-15 FDA Drug Review:Postapproval Risks 1976-1985
And 45 drugs tested in 1978 were analyzed. Of the side effects predicted by animal studies, 75% did not happen in humans.
AP Fletcher in Proc R Soc med, 1978;71, 693-8
In the periods 1978-1988, 25 drugs were found to treat stroke (although there is no model of "stroke" in animals. The number, which worked in humans, was found to be zero.
Cerebrovascular Diseases 1979, Raven, 87-91
Anti-cancer drugs are very toxic in animals and associated
with severe side effects in humans, although they are clinically used. How did they make it to treat cancer patients given their toxicity?
Based on animal testing, the predicted difference between the pharmacological dose and the toxic dose must be small. However, it might be worth taking the risk of having the drugs on the shelves if cancer can be stopped with a reasonnable chance to survive to the side effects.
The field of chemotherapy was opened by chance discovery when
monitoring the effects of actinomycin-D in humans. This compound later fell into disuse, as it is neutral in mice and lethal to non-human primates. Cyclophosphamides were derived from nitrogen-containing mustards, used during World War I, by chance (although a global war is not an alternative to find drugs, obviously). Many other chemotherapy agents were discovered through clinical observations, in vitro studies on human tissue, because results from mice were too inconsistent and irrelevant; cisplatine, tamoxifen did not work as a contraceptive but was good as an anti-cancer agent.
Nineteen chemicals known to cause oral cancer in humans were studied in animals. Using the standard National Cancer Institute Protocol, and rats and mice, twelve were found to be safe in animals.
Fund Appl. Toxicolo 1983;3:63-67
Other experiments on rats and mice show that 46% of chemicals, which caused cancer in rats, were not cancer inducing in mice. Mice were found to develop cancer due to exposure to chemicals which did not affect rats.
FJ Di carlo, Drug Met Rev, 1984;15:409-13, E Efron, The Apocalyptics, Simon & Schuster, NY 1984
Over 500,000 different chemicals were tried on animals in an attempt to find some that would combat cancer. From this mammoth operation, just eighty drugs were identified using the animal tests. Of these eighty, only twelve went on to make a difference. Those 12 drugs could have been predicted based on the structure of already known anti-cancer agents.
There is mounting scientific evidence that animal testing is misleading and dangerous. The current system is not perfect but it can be improved because there are other ways. Behind the facade of medical establishement, people have suffered and will continue to suffer from the reliance on animal models, either because they are prescribed dangerous products (eg. VIOXX-MERCK) or simply because they take medicines that have no therapeutic value.
It is demonstrated from the basic observation that non-human animals and human animals are physiologically, anatomically, sexually, psychologically and at the cell and molecular level, similar but significantly different to lead judgment into error for generations and generations. On the one hand, animal experimentation and testing can claim some historical successes, but on the other hand, such methodology has delayed medical science and continue to cause its plethora of injuries and death.
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