In March, 2013, the U.S. Food and Drug Administration (FDA) approved Invokana (canagliflozin) for use in treating type 2 diabetes in spite of the fact that five out of 15 experts voted against approving the drug and those who voted in favor of the drug had some serious reservations about its safety. The FDA questioned the safety of Invokana too, and required five separate post-marketing studies to further examine the risks and consequences after the dangerous drug was unleashed on the public.
Invokana is a New Type of Diabetes Drug
When a new type of drug emerges, there is often a lot of excitement in the medical community, but there are also a host of unknown risks.
Dr. Sidney Wolfe, director of Public Citizen’s Health Research Group, testified before an FDA advisory committee regarding Invokana approval, and warned of several health risks posed by the drug. Dr. Wolfe said, “The fact that the drug works by a uniquely new mechanism to lower blood sugar has not spared of a whole set of unique new risks. The FDA has previously made too many mistakes in approving drugs, including those for diabetes, with no unique clinical benefits and unique risks. The agency shouldn’t approve this one.”
Invokana was the first in a new class of diabetes drugs to receive FDA approval. The class is called sodium-glucose co-transporter-2 (SGLT-2) inhibitors. They work by blocking the reabsorption of glucose in the kidneys and forcing glucose to be excreted in the urine.
SGLT-2 inhibitors had a poor history with the FDA before the first one was even approved. In 2012, another SGLT-2 inhibitor, Farxiga (dapagliflozin) was rejected by the FDA due to concerns of an increased risk of breast and bladder cancers. It was approved in 2014.
Warnings against Invokana Approval
According to an article in the New York Times, some of the experts warned that Invokana should not be prescribed to patients with moderate kidney disease because it is not as effective in such patients and the risk of adverse events is elevated. Dr. Sanjay Kaul was one of the doctors who voted for approval, but expressed several concerns, including a lack of sufficient data on risk to patients with moderate to severe renal impairment. He also expressed concern about the significant increased risk of genital and urinary infections.
Dr. Wolfe raised the issues of an increased risk for low blood pressure symptoms, adverse cardiac events, and genital and urinary infections.
Although clinical trials showed elevated stroke risk, and increase in heart attacks within the first 30 days of taking the medicine, and raising of LDL cholesterol, an FDA spokesperson said that the significance of the findings was unclear and the drug would not carry a warning label for those potential dangers.