Pioglitazone anti-diabetic drug cause 40% rise in the risk of bladder cancer

Doctors say go slow on use of diabetes drug after study sees cancer risk
Published in Times of India Dt. 3rd June, 2012

Chennai: Doctors in India are seeking restraint in the use of commonly used anti-diabetic drug pioglitazone after studies showed that it increases the risk of bladder cancer. Diabetologists in India say they are already seeing bladder cancers even among those who have been on lower dosages of the drug for two years or more.

    Piolglitazone, sold under many brand names such as Glizone and Pioz in India, is a prescription drug of the thiazolidinedione class that is used to bring down sugar levels in diabetics. Another medication in the same class, rosiglitazone, was withdrawn from the market in 2010 following studies showed increased risk of cardiovascular diseases.

    Now, a study published in the British Medical Journal has said exposure to pioglitazone for two years may more than double the risk of developing bladder cancer. The bladder cancer risk among patients taking the drug increases by about 83% compared to the rest of the population, the researchers said.

    Of the 115,727 patients in the UK who were part of the study, 470 of them were found to have bladder cancer. This would mean that one in every 250 patients taking the drug for more than two years is at increased risk for cancer.

    There has been no detailed study on the effectiveness of the drug in India. US agency found drug increased risk of cancer
    Some doctors say they are beginning to see new bladder cancer cases in people who have been taking lower doses (15mg) of the drug for two years.

    As a part of an ongoing study, Madras Diabetes Research Foundation has collected medical details of eight patients who developed bladder cancer after being prescribed pioglitazone. The patients were from Mumbai, Hyderabad, Chennai, Belgaum and Salem. “None of them had bladder cancer before they were prescribed the drug. It is possiblethateven lower dosages increase the risk in Indians,” said foundation director Dr V Mohan.

    The US Food and Drug Administration warned in June 2011 that taking pioglitazone for at least a year increased the risk of bladder cancer by at least 40%, and ordered the drug’s manufacturer to note the risk on the drug’s label. The drug is banned in some countries like France and Germany. Dr Mohan insists that the drug should be banned for new patients and those who have been on the drug should be warned about the risks.

    But some diabetologists argue that the benefits outweigh risks andthedrug has notbeen shown as the cause of bladder cancer, and the researchers themselves say that the risk applies to people who have been taking the maximum dosage -- 45mg every day -- for two years. They also add that it should be continued as no risk has been proved for those taking 15mg and 30mg. “Itisoneof the most effective drugs to bring sugar levels under control. Without this drug, the only option for the patientisinsulin,” said a senior diabetologist, refusing to be named.

    India has 61 million diabetics – a sizeable increase from 50.8 million in 2010. The International Diabetes Federation estimates that by 2030, India’s diabetes burden is expected to cross the 100 million mark as against 87 million estimated earlier.

http://www.bmj.com/rapid-response/2011/11/03/ema-bis-repetita
http://www.bmj.com/search/pioglitazone