Another diabetes drug mired in controversy

One more diabetes drug has now entered the realm of controversy. With France and Germany banning 'pioglitazone' (marketed under the brand name Actos) following reports that it raised the risk of bladder cancer in long-term use, debates have begun to rage in India as well.

"This follows a rather recent controversy over the increased risk of heart attacks and fractures associated with rosiglitazone, from the same stable as pioglitazone. The French study was conducted by the country's health insurance agency and studied over 1.55 lakh people on the drug over a three-year period," says V.Mohan of Dr. Mohan's Diabetes Specialities Centre.

Dr. Mohan says the pioglitazone group was matched against diabetics who were not on the drug. "We learn that there was a slightly increased risk of bladder cancer. Not any other form of cancer, the narrowing down to the bladder shows the clear link to the drug," Dr. Mohan adds. Longer exposure and higher dosages lent to the increased risk of bladder cancer.

Earlier, the April volume of Diabetes Care published the interim report of a study on risk of bladder cancer associated with pioglitazone. It noted that use of the drug for more than two years was weakly associated with increased risk. In June this year, Diabetes Care published yet another study, this one from Italy, which concluded that there was an association between pioglitazone and bladder cancer. It also urged that the issue needed constant epidemiologic surveillance, and more specific studies.

With the media picking up news on the ban already, diabetologists have has been inundated with calls from patients who are on pioglitazone and are concerned about continuing it.

Anoop Mishra, Director and Head, Department of Diabetes and Metabolic Diseases, Fortis Group of Hospitals, says, "The issue was already on consideration for some time because of some suspicions. There is now preliminary evidence after the French study. The FDA is also considering the issue." However, it is too early to make a definitive conclusion, he says, adding that it is best to use pioglitazone sparingly when no other alternative is available.

Vijay Viswanathan, MD, M.V. Hosptial for Diabetes, Royapuram, says the second-line drug has been used for about 10 years now in India. "We have seen no instances of bladder cancer so far in our patients. In fact, it is a very successful molecule as far as control of blood sugar goes. The moment we stop the drug (sometimes because of weight gain), the patient has to go on insulin. We have to examine the studies," he explains.

A.Panneerselvam, of Aruna Diabetes Centre, advises patients not to panic. "Do not stop the drug based on media reports. Stopping pioglitazone will lead to blood sugar levels shooting up," he says.

The clear message is one of caution for the patient. Dr. Mohan explains, "All we are saying at the moment is consult your diabetologist. Do not stop or start drugs without medical advice."

Source: The Hindu