Reports of serious side effects of Avandia, an anti diabetic drug marketed by GSK worldwide, has once again raised serious doubts about the safety of several modern drugs in the market. Avandia, GSK's brand name for rosiglitazone, was approved by the US FDA in May 1999 for the treatment of type 2 diabetes and the drug is a widely prescribed blockbuster in the US and European markets. The concern about the safety of Avandia was raised with the publication of a study in New England Journal of Medicine by the prominent US cardiologist Dr Steven Nissen of the Cleveland Clinic. The study suggested that the patients who are taking the drug have 43 per cent higher chances of suffering a heart attack. GSK has however strongly disagreed with the findings of Dr Nissen and is of the view that Avandia is no riskier for the heart than other diabetes medications. Several millions of patients are already taking rosiglitazone world over including in India. GSK's initial response to Nissen's findings is not surprising considering the stakes involved in a possible withdrawal of the drug from the major markets. It is the second largest revenue earner for GSK and only just two years ago, the MNC had to withdraw its anti depressant drug, Paxil, from the US market for its side effects leading to suicidal thinking amongst adolescents.
Dr Nissen's Avandia study has not convinced US FDA to resort to any serious step to limit its use among patients in the US. It just issued an alert to the physicians and patients. A mere advice by the FDA on such a serious issue involving high risks to patients leaves away a lot of its responsibility being a custodian of public health. FDA has not confirmed the clinical significance of the reported increased risk. And the questions remain to be answered include whether other approved treatment from the same class of drugs, pioglitazone, has less, the same or greater risks. Avandia is supposed to be taken in addition to diet and exercise to improve blood sugar control. In March 2000, the Public Citizen, a consumer group, petitioned the FDA for the immediate revision of "inadequate, misleading, and potentially dangerous professional product labelling" for the diabetes drugs referred to as "glitazones", which include Rezulin, Avandia and Actos. Avandia and the other two glitazone drugs were approved as adjuncts to diet and exercise in order to improve blood sugar control in type 2 diabetes patients but the drug labelling was inadequate and did not mention safety and efficacy information relevant to all three drugs in the class. Rezulin was the first drug of the Avandia class to be approved and was subsequently banned in UK. By 2000, Rezulin was also recalled in the US on account of instances of liver damage leading to death or needing costly liver transplants. Another major withdrawal of a blockbuster drug for adverse reactions was that of Vioxx of Merck in 2004. Shortly after this, Pfizer withdrew its arthritis pain killer, Bextra, from the market for safety concerns in April 2005. Now, the US FDA is also examining Eli Lilly's psychotic drug, Zyprexa, another blockbuster, for its safety in the wake of reports that the use of the drug can develop high blood sugar. All these post marketing complications of newly approved drugs especially during the last five to six years force one to think that there is something wrong with the whole system of new drug approval by world's top regulatory bodies. This is an extremely serious matter to ponder about by the health authorities and patient community especially when regulatory bodies like US FDA are involved.