More than nine out of 10 scientists who backed a drug at the centre of a safety scare had financial links to the pharmaceutical industry, a study has found.
The disclosure will renew concern about the influence of the multinational companies on patient safety, where a warning about a drug can wipe billions from their balance sheets.
The pharmaceutical industry has become adept at manipulating results and selectively withholding unfavourable data that could expose patients to harm.
Now it is accused of skewing the debate over one drug, Avandia, prescribed to millions of people with Type 2 diabetes.
Avandia, made by the British multinational GlaxoSmithKline (GSK), which helps diabetics control their blood sugar levels, was linked with an increased risk of heart attacks in research published in 2007.
Since then debate has raged within the scientific community about whether Avandia should be withdrawn from the market.
Avandia was one of the biggest selling drugs in the world with sales of more than $3bn (£2bn) in the US alone in 2006. But when the FDA issued a warning following the 2007 research linking the drug with an increased risk of heart attacks, sales plunged.
Now the FDA is reviewing the drug for a second time and is due to announce its findings in July. No review is planned in the UK.
Researchers from the Mayo Clinic in Minnesota — one of the few US research organisations that does not rely on commercial sponsorship — analysed more than 200 articles published in scientific journals, including original papers, editorials and letters, which commented on the heart attack risk.
Writing in the British Medical Journal, the Mayo Clinic researchers say: “ We aimed to determine whether financial conflicts of interest with pharmaceutical manufacturers could be fuelling this fire. From our findings, it appears that the answer is yes.”
A Diabetes UK spokesperson said: “We would not advise people to stop taking Avandia.”