What is Invokana?
Invokana (generic name Canaglifozin) is an orally-administered drug used for the treatment of type-2 diabetes. It was the first of a new class of drugs known as ‘SGLT2 inhibitors’ to be approved by the US FDA. These drugs function by blocking the reabsorption of glucose, causing it instead to be secreted in the urine.
Since the drug was only approved for use in May 2013, many consequences of taking Invokana long-term are still unknown. Due to concerns which arose during the approval process, the FDA required several long-term studies to monitor groups of Invokana users, watching for several potential health complications which may be caused by the drug. The results of these studies are not yet available.
Though it is not FDA-approved for the treatment of type-1 diabetes, Invokana is frequently prescribed off-label for that purpose as well.
The FDA’s approval of Invokana caused considerable controversy, with five experts on the fifteen-member panel voting to reject the drug due to unanswered concerns. The latest of these concerns to come to light, following several endocrinological studies, is the link between Invokana use and diabetic ketoacidosis, a serious health condition caused by a build-up of toxic blood acids. At its most serious, ketoacidosis can cause coma or death.
Other serious health concerns include an increase in heart attacks and strokes in Invokana-users, especially in the first 30 days of use. Despite compelling evidence of cardiovascular issues prior to approval of the drug, Invokana’s label carries no warnings to prescribing doctors regarding using caution with patients who already have cardiovascular risks.
Dr. Sanjay Kaul, who voted in favor of approving the drug, even notes “my vote came with many caveats,” due to the lack of available data on Invokana’s risk to patients with moderate to severe renal impairment. He also notes that the drastic increase in genital fungal infections (from four- to seven-fold increased risk) is unlikely to make the drug beloved by patients.
Related drugs have been rejected by the FDA due to concerns with connections to increased cancer risk and liver failure.
To make matters worse, the drug has a fairly weak glucose-lowering potential compared to drugs such as metformin, which are not only effective, but also available in much cheaper generic varieties. Considering the potential pitfalls in this new class of drugs, many have questioned whether Invokana is even needed.
As endocrinologist David M. Nathan, professor of medicine at Harvard Medical School put it: “I do remain generally concerned regarding this flooding of the market with diabetes drugs that really are not substantially better, and in some ways worse, than the older, less expensive, generic drugs that are available.”