Large firms hyped-up patented medicines, spent vast amounts on getting doctors to prescribe them and underplayed serious side effects, said Prof Donald Light, a sociologist and professor of comparative health policy at the University of Medicine and Dentistry in New Jersey, US.When the "toxic side effects" of prescription drugs were taken into account, and their misuse, he claimed they were "a signficant cause of death".Chloresterol-lowering statins were a classic example of the drugs industry overselling a product as a wonder-pill to prevent heart attacks, despite evidence that they could do more harm than good, he claimed.In a paper that he presented to the American Sociological Association (ASA) on Tuesday, he said pharmacuetical companies were guilty of creating a "market for lemons" - one in which the seller knows much more than the buyer about the product, and takes advantage of this fact.He said: "Sometimes drug companies hide or downplay information about serious side-effects of new drugs and overstate the drugs' benefits."Then, they spend two to three times more on marketing than on research to persuade doctors to prescribe these new drugs."Doctors may get misleading information and then misinform patients about the risks of a new drug. It's really a two-tier market for lemons."He claimed it was the "most dangerous market for lemons in modern society", with toxic side effects and misuse of prescription drugs making them a significant cause of death in the US."Neither wars nor used car injuries come close," he said.His allegations have been dismissed by the Association of the British Pharmaceutical Industry (ABPI), which said he was "long on accusation and woefully short on hard evidence",But Prof Light, who has also written articles for the British Medical Journal and the Lancet, said data from independent reviewers suggested that five out of six (85 per cent) of new drugs provided few, if any, new benefits.His claims are outlined in the paper and also a book, The Risk of Prescription Drugs, due to be published this autumn.With statins, he said drugs companies had boiled down complex set of relationships between heart disease and saturated fats and cholesterol into the over-simplistic message that "cholesterol kills".Yet two major trials of statins found little evidence they reduced the risk of heart attacks. One major meta-analysis of a number of studies, found that "statins were not associated with reduction in the risk of all-cause mortality", he said.Prof Light argued: "Current incentives for research produce a few [drugs] that substantially improve patients' chances of getting better or avoiding death but a large number of barely innovative drugs each year."These new drugs of little benefit consume about four-fifths of all drug costs."He accused companies of swamping drugs regulators with large numbers of "incomplete, partial, sub-standard clinical trials"."The result is that drugs get approved without anyone being able to know how effective they really are or how much serious harm they will cause," he said.When patients complained of adverse reactions, studies showed doctors were likely to dismiss them, he said.However, the ABPI issued a stern defence of the sector. A spokesman said: "Millions of people are alive today thanks to medicines. Medicines have transformed the management of conditions which previously caused death, impaired the quality of life or required hospitalisation."There is still great unmet medical need and the pharmaceutical industry is actively researching new cures to address these illnesses.She noted there was now "much greater transparency in clinical trial results" with companies registering their results on websites such as www.clinicaltrials.gov."The UK pharmaceutical industry also adheres to a strict code of practice on the sales and marketing of its products."A spokesman for the Medicines and Healthcare products Regulatory Authority said it recognised the need to expand knowledge of new drugs' possible side effects in the wider population after clinical trials."For this reason the safety of all medicines is monitored closely by the MHRA," she said.