While the diabetic medication Invokana (canagliflozin) has been implicated in the development ketoacidosis in patients, it is not the only prescription drug in its class to have such a serious side effect. It was well over a year ago (May 2015, to be exact) that the Food and Drug Administration issued a statement on receiving numerous reports of how the entire class of gliflozin drugs was causing dangerous ketoacidosis. In fact, during the two years prior to issuing that statement, the FDA had received in excess of 100 reports of serious kidney damage. While most of these were due to Invokana, a little under a third of the patients reported taking Farxiga, another gliflozin drug. Nearly all of them were admitted to the hospital, and a significant number required intensive care.
What is even more shocking is half of these victims had been taking gliflozins for 30 days or less.
The same was true for patients taking gliflozin drugs who suffered heart attacks and strokes. In a clinical study involving patients at elevated risk of cardiovascular disease, 13 suffered either a heart attack or stroke within a month of starting Invokana. Interestingly, that study was carried out by Johnson & Johnson, parent company of Janssen Pharmaceutica, which sells the medication under license from manufacturer Mitsubishi Tanabe Pharma. Yet, according to a story in the New York Times, “... the significance of those findings was unclear, and the label of the drug includes no warnings about heart attacks or strokes.”
That was in 2013, shortly after the drug won FDA approval. Because there was no explicit label warning, primary care physicians could not know about the risks to which their patients were being exposed, even after a careful review of the prescribing information. In fact, it wasn't until May of 2016 – more than a year after the FDA released its statement on adverse events associated with Invokana – that the warning label was updated to include the risk of kidney damage from ketoacidosis.
Significantly, the only people who usually have to worry about ketoacidosis at all are those suffering from Type 1 diabetes. This is really an entirely different condition, though the symptoms are similar. Type 1 is a genetic disorder that is typically diagnosed in early childhood – and ketoacidosis is only a concern for patients with poor glucose control (blood sugar levels of 300 mg/dl or greater).
However, ketoacidosis has been occurring in patients with Type 2 diabetes whose glucose levels are only moderately elevated (140 to 200). The reason is that gliflozin drugs may be interfering with the normal physiological processes that keep ketone levels in check. This makes drugs like Invokana particularly dangerous for Type 2 diabetics who may be controlling their blood sugar levels with a diet low in carbohydrates (such as the “paleo” diet). In fact, it is entirely possible to control glucose levels through a combination of diet and exercise while taking the relatively harmless old standby, metformin.
But that wouldn't be profitable for Johnson & Johnson's Janssen division, which has marketed Invokana aggressively – and for which Invokana sales were in the neighborhood of $1 billion last year.
That fact says it all.