November 14, 2007, the FDA announces that GlaxoSmithKline‘s (GSK) Avandia (rosiglitazone) is to bear a second blockbuster killer – a black box warning label. Like all black box warnings, it states that doctors should be careful about prescribing the drug and to especially weigh out the pros and cons. Specifically in Avandia’s case, the drug exacerbate conditions of heart failure patients (which was the first one that it received in August of this year) and then now a second label is to be added indicating that the drug could cause heart attacks heart related risks (this correction was also made by the FDA). This drug has been known for since its introduction to worsen heart failure and presumably prescribers were not writing it for their patients who had heart failure, but the news for heart related risks and ambiguously, for heart attacks, is new.

Whatever the case maybe, Avandia now has a second black box warning. According to the TNS Healthcare’s Diabetes Dynamics USA™, for the time period from July through September 2007, 70% of all prescribing instances of Avandia was through discontinuation. Avandia and their drug groups (GSK has combination drugs which contain Avandia) is a $2.3 billion a year drug (according to GSK). What typically happens to drug which gets a black box warning is that their prescription rates drop down to 10% of what it was before (Pfizer‘s Celebrex did). For GSK, this means a loss of $2.1 billion in gross revenues. Prescribers shy away from writing black box labeled drugs because it increases their likelihood of being sued for malpractice as lawyers tend to pick at details that are out of normal practice. Avandia, now has two black box warnings.

Yet another damnation to Avandia emerged when the US Department of Veterans Affairs (VA) revealed last month that it is removing Avandia from its list of approved drugs, and will severely limit its use. The VA will recommend that patients currently taking Avandia may continue, but strongly urge doctors to discus the associated risk with their patients. VA sales of Avandia represent about 8 per cent of total US Avandia sales, which have fallen an estimated sixty per cent since May.

Avandia is an anti-diabetic drug which was approved by the FDA in May of 1999 for single therapy or in combination with other anti-diabetic medications such as metformin (Glucophage). Avandia belongs to a group of drugs called thiazolidinediones or “insulin sensitizers”, in the medical community, it is recognized that thiazolidinediones is not a very good group to be used as monotherapy for diabetes but is great in adjunct therapy to other medication as their results are synergistic. The only other drug in this group is Actos (pioglitazone) of Takeda Pharmaceuticals. Takeda is the largest pharmaceutical company in Japan.

Sources here . FDA . here .

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