In addition to kidney damage, ketoacidosis and heart attacks, it turns out that canagliflozin – sold under the brand names Invokana and Invokamet – increases the risks of osteoporosis, or loss of bone density.

In clinical studies, elderly Type-2 diabetics treated with Invokana for two years or more showed reduced bone density in their lower spines and hips. While many people lose bone density as they get older, the recent studies show that treatment with Invokana can greatly accelerate the process. Some patients can suffer fractures in as little as three months after starting on the medication. Risks of bone loss and fractures were most pronounced in post-menopausal women.

The study, part of a post-marketing safety evaluation, continued for two years and involved more than 700 geriatric patients. According to a statement from the Food and Drug Administration (FDA) issued on September 10th, “The additional data confirm the finding that fractures occur more frequently with canagliflozin [Invokana] than placebo…fractures can occur as early as 12 weeks after starting the drug.”  Additional data was gathered from nine other clinical trials in which test subjects took the drug for an average of 85 weeks.

As a result of this new data, stronger warnings will be added to Invokana prescribing information.  The FDA is advising physicians to consider the risk of bone fractures before prescribing Invokana for their diabetic patients. In addition to Invokana, the FDA is monitoring similar medications in the class of SLGT2 inhibitors, or gliflozins.  These prescription drugs target a specific protein, known as sodium/glucose co-transporter 2. This protein is involved in the reabsorption of blood sugar (glucose) in the kidneys. SLGT2 inhibitors allow excess glucose to be passed in the urine. In addition to kidney damage, these drugs also increase the risk of urinary tract infections, vaginal yeast infections and dangerously low blood sugar levels (hypoglycemia). Other drugs in the gliflozin class include Farxiga (dapagliflozin), Jardiance (empagliflozin) and Glyxambia (linagliptin). All of these drugs will be under FDA scrutiny over the next several months.

Physicians are also being urged to monitor patients for diabetic ketoacidosis (DKA) when prescribing gliflozin drugs such as Invokana. An research study recently published in the journal Diabetes Care noted over 100 patients worldwide who wound up suffering serious cases of DKA as the result of taking gliflozin medications. All of these cases were serious enough to warrant hospitalization.  Untreated, the condition can cause patients to lapse into a coma, and can even result in death.

This brings up another issue, which has to do with the FDA approval process. In the journal article, the researchers state, “It is not unusual that serious safety issues related to a new drug go undetected during the relatively short clinical development programs for regulatory drug approval.”  When introduced, Invokana was hailed as a “miracle drug.” However, concerns over the safety of Invokana were expressed early on. Furthermore, there is evidence that both drug maker Janssen and the FDA were aware of these dangers before Invokana was approved.

In too many cases, new “miracle” drugs are rushed to pharmacy shelves before they have been adequately tested. Despite testimony from medical experts who expressed serious concerns over the safety and efficacy of canagliflozin, the FDA went ahead and gave market approval for Invokana – on the condition that the manufacturer would do its own monitoring for “adverse events.”

Considering the potential profits at stake (the market for diabetic drugs is expected to reach well over $55 billion by 2017), there is little incentive for pharmaceutical companies such as Janssen to do rigorous and unbiased testing of their products. Until federal regulators are willing to stand up to Big Pharma, expect more adverse events resulting in injuries and death.

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K.J. McElrath is a former history and social studies teacher who has long maintained a keen interest in legal and social issues.