GlaxoSmithKline is updating the prescribing information for Avandia to include clinical findings that users have better glycemic control with the drug than with two other diabetes treatments. However, critics who have voiced safety concerns about Avandia, point out that the better control of blood sugar is not particularly useful, since side effects of the drug could increase the risk of a potentially fatal heart attack.
Avandia is a medication prescribed to individuals with type 2 diabetes. Until last year, it was one of the top selling medications in the United States, with annual sales of over $2 billion. However, a May 2007 study published in the New England Journal of Medicine indicated that users could face a 43% increase in the risk of suffering a heart attack while taking Avandia, which has caused many doctors to switch their patients to other drugs.
Many critics of Avandia called for the drug to be recalled after this meta-analysis was published. However, after debate within the FDA, a black box warning was added In November 2007 about the potential Avandia heart attack risk instead of removing the drug from the market.
On July 14, the FDA approved new information which Glaxo will add to Avandia’s label about a four to six year study, known as ADOPT, which compares Avandia to metformin and glyburide monotherapy among individuals diagnosed with type 2 diabetes. At five years, data suggests that 15% of patients on Avandia showed inadequate glucose control as compared to 34% of those taking glyburide and 21% of those taking metformin.
According to a report from HeartWire, prominent cardiologist Dr. Steve Nissen points out that while ADOPT did show better blood sugar control for Avandia users, the relative risk of a heart attack was 33% higher with the drug, which is consistent with the four meta analyses that led to the black box warning. Dr. Nissen, who is at the Cleveland Clinic, co-authored the May 2007 study that was published in the New England Journal of Medicine. He was also instrumental in bringing attention to heart risks associated with Vioxx, an arthritis drug, which was eventually recalled in 2004.