Trial and error


By Michael Day ONE of the researchers who exposed the dangers of using albumin in patients suffering from serious burns or shock says new drugs for high blood pressure face unanswered questions regarding their safety. Two weeks ago, Ian Roberts of the Institute of Child Health in London and his colleagues said in the British Medical Journal (vol 317, p 235) that albumin, which has been in use for more than 30 years, claims more lives than it saves. After an analysis of patient records, they concluded that it causes around 1200 extra deaths in critically ill patients in Britain each year. Now one of the team, Alain Li Wan Po of Nottingham University, says data on the safety of six drugs to treat high blood pressure, which have or are about to get licences in Britain, are inadequate. Li Wan Po has been involved in safety testing of some of the drugs. They are all a new class of “centrally acting antihypertensives”, which target receptors in the brainstem that orchestrate the dilation of blood vessels. One of the drugs, moxonidine, is already licensed in Britain. Li Wan Po cannot name the others because he has signed confidentiality agreements while working on the safety studies. He believes the licensing regulations are not strict enough to ensure the six drugs are safe. Large-scale controlled trials of the drugs took place for three to four years. But Li Wan Po says only controlled trials over decades will reveal whether the new drugs reduce heart attacks, strokes and deaths. Brian Pentecost, medical director of the British Heart Foundation and a member of Britain’s Committee on the Safety of Medicines, agrees that the lack of controlled data for newer heart drugs is “a cause for concern”. But Lawrence Ramsay, a specialist in heart drugs at Sheffield University, suggests it is unreasonable to expect drugs companies, which may have invested hundreds of millions of pounds developing a single drug, to wait for decades to recoup their costs. He believes that tests on drugs for high blood pressure should continue after the drug is licensed. “I would like to see the licensing agency be willing to license drugs only on the understanding that the company must continue controlled clinical trials after a licence is given.” Jackie Stone, medical information adviser for Solvay, which makes moxonidine, points out that the company has provided all the data required for licensing. “If we didn’t come up with enough safety data, we wouldn’t get a licence,” she says. “We have 500 000 patient years experience with moxonidine.” But Ramsay responds that it’s difficult to see problems emerging when no controlled studies follow licensing. Li Wan Po believes another problem is that data on drugs are not always freely available. On discovering the dangers of albumin, Roberts wrote to the British Medicines Control Agency requesting all the data that the MCA had on albumin. But a written reply from the MCA told Roberts the agency didn’t have time to provide all the published data and that it would not supply unpublished data unless Roberts cited specific studies. In a Lancet editorial later this month, Li Wan Po will call for all company data to be freely available from the MCA. A spokesman for the Association of the British Pharmaceutical Industry says all data in licence applications is freely available,
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