Nexus - 0802 - New Times Magazine-pages

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UNSAFE FOR HUMANS he following, taken from Dr Ray and Jean Greek's book, are just some examples of pharmaceutical drugs which have been deemed safe for human use after extensive animal testing, but which were later found to cause serious side effects. + Amrinone: Use of this drug for treating heart failure led to 20 per cent of patients developing thrombocytopenia (a lack of blood cells needed for clotting), despite a comprehensive program of animal studies in mice, rats, hamsters, guinea pigs, dogs and rhesus monkeys. Some of these patients died. - Birth control pills: These are known to cause life-threatening blood clots in some women, yet scientists have still not been able to reproduce this finding in animals. In fact, dog testing predicted that the pill would decrease the likelihood of clotting. + Chloramphenicol: This antibiotic caused life-threatening anaemia in humans. Chloramphenicol is an example of a drug whose effects vary from species to species: dogs do well with it, cats die from it, cows tolerate it but horses do not. It is so toxic to susceptible humans that its use has been outlawed in animals used for food. The tiny amount consumed from ingesting a hamburger made from a treated cow will cause death in such a person unless they receive a bone marrow transplant. - Clioquinol: This anti-diarrhoeal passed tests in rats, cats, dogs and rabbits. It was pulled off the shelves all over the world in 1982 after it was found to cause blindness and paralysis in humans. Diethylstilbestrol : This synthetic oestrogen was designed to prevent miscarriage, but it did just the opposite by increasing the rate of spontaneous abortions, premature births and neo-natal deaths. No human trials were done; all the safety data were col- lected from animals. -Eraldin: This heart drug was withdrawn in 1975 after causing serious side effects in an estimated 7,000 victims, 23 of whom died. It had been tested for six years in mice, rats, dogs and monkeys and when introduced on the market was "particularly notable for the thoroughness with which its toxicity was studied in animals, to the satisfaction of the authorities".'° Even long after the drug was withdrawn, scientists failed to repro- duce these results in animals. + Floxin: This antibiotic progressed through animal testing, only to cause seizures and psychosis when used by humans. - Isuprel: A medication used to treat asthma, it proved devastatingly toxic to humans in the amounts recommended based on animal studies. In Great Britain alone, 3,500 asthmatics died from using the medication. + Manoplax: This heart drug, which had been tested on rats, mice, rabbits, cats and guinea-pigs, was withdrawn worldwide in 1993 after analysis of patients showed that those taking it were at increased risk of hospitalisation and/or death. + Methysergide: This treatment for migraine led to severe scarring of the heart, kid- neys and blood vessels in the abdomen, although scientists have been unable to repro- duce these effects in animals. + Opren: This treatment for rheumatism and arthritis killed 61 people and caused 3,500 adverse reactions. Withdrawn in 1982, the drug had been tested on monkeys and other animals for nine years with no adverse side effects. + Phenylpropanolamine (PPA): This drug, found in many common cold and flu reme- dies, was banned by the FDA in the US after it was linked to causing between 200 and 500 strokes in young women a year. + Primacor: This medication, given when the heart is not pumping enough blood, worked well in rats but increased deaths in humans by 30 per cent. + Ritodrine: This drug, prescribed to avert premature labour, induced pulmonary oedema (fluid in the lungs, causing breathing difficulties and possibly death). + Suprofen: This arthritis drug was withdrawn from the market when patients suffered kidney toxicity. Prior to its release, researchers said this about the animal tests: "...excellent safety profile. No...cardiac, renal [kidney] or central nervous system [side effects] in any species." + Tamoxifen: This drug, used to treat and prevent breast cancer in women, caused liver tumours in rats but not in mice or hamsters.'? The drug has been shown to be harmless to the developing foetus of rabbits and monkeys, but to cause bone abnor- malities in rat foetuses.'? One of the side effects is nausea and vomiting, but this was not predicted in animal studies, even though high doses were tested in dogs—the species considered most predictive of vomiting in humans."* The drug has also been implicated in uterine cancer, blood clots, memory loss, absence of periods, and eye damage such as cataracts."° = Zomax: This arthritis drug killed 14 people and caused many more to suffer. "We differ on the cellular level and mol- ecular level and, importantly, that is where disease occurs," the authors explain. "The cells of chimps are very similar to [the cells of] humans, but the spatial organisa- tion of the cells is vastly different." Even those who favour the animal model admit its unpredictability among their peers. Dr Ralph Heywood, director of Huntingdon Research Center in the United States, says: "The best guess for the corre- lation of adverse reactions in man and ani- mal toxicity data is somewhere between five and 25 per cent."® Dr Herbert Hensel, Director of the Institute of Physiology at Marburg University, goes further: "In the opinion of leading biostatisticians, it is not possible to transfer the probability predictions from animals to humans... At present, there- fore, there exists no possibility at all of a scientifically based prediction. In this respect, the situation is even less favourable than a game of chance."” Even the most widely respected textboo on animal experimentation states: "Uncritical reliance on the results of animal tests can be dangerously misleading and has cost the health and lives of tens o thousands of humans."* The best-known example of this is thalidomide. Mothers who took this drug to ameliorate morning sickness gave birth to children with shocking deformities, wit most lacking developed limbs. Anima tests had not predicted this. The first recorded case of side effects occurred on Christmas Day 1956, but in 1957 the drug was released anyway.’ QUESTIONABLE ACCURACY OF TOXICITY TESTS Ox of the reasons why so many drugs cause adverse reactions in humans— reactions which were not predicted in animals—is because of the inaccuracy of the toxicity tests carried out. The most notorious of these is the LDS0 Draize test ("LD50" stands for "Lethal Dose 50 per cent"), where animals—usual- ly dogs and rats—are force-fed, forced to inhale or are injected with a chemical until 50 per cent of them die. That dosage is then designated as the LDS50. Its unrelia- bility is obvious when we consider the huge variables such as the age, weight and gender of the animals, not to mention the environmental conditions under which the test takes place. These variables render the results invalid even for the species tested, let alone for humans. The LDS0 test was still part of almost all 28 = NEXUS FEBRUARY — MARCH 2001