Researchers in a canagliflozin clinical trial found that Invokana users were twice as likely to undergo a lower limb amputation than those receiving a placebo. Unfortunately, that risk increases for patients who already suffered from a previous amputation. In 2017, the FDA issued a safety warning about this new risk for Invokana users, mandating Invokana to carry a Black Box warning—the most serious label warning the FDA can issue—about amputation risks. One 2017 study indicated that Invokana use increased leg and foot amputation risk by a massive 97%. Researchers speculated that this could be caused by the Invokana decreasing blood flow to the lower limbs, exposing legs, feet, and toes to high infection risks.
Symptoms/Conditions Preceding Lower Limb Amputation:
Necrotizing fasciitis, otherwise known as Fournier’s gangrene, is a grave flesh-eating bacterial infection. The infection impacts the nerves, fat, muscles, and blood vessels around the genitals. This side effect of SGLT-2 inhibitors can be life threatening if left untreated. While the disease usually occurs in men, women are susceptible to the disease as well. As a degenerating disease, Fournier’s gangrene worsens over time, surgical procedures often becoming necessary for victims. But, if caught in the early stages, necrotizing fasciitis can be treated with antibiotics.
In August 2018 the FDA mandated new boxed warning labels for Invokana after cases of Fournier’s Gangrene arose in patients taking drugs like Invokana. Boxed warning labels are the most severe warnings the FDA can issue for a drug, but the alert came too late for Invokana users. Since 2013, 12 patients prescribed SGLT-2 inhibitors, like Invokana, developed necrotizing fasciitis of the genitalia, one of those cases resulting in death. A study released May 2019 confirmed the serious risk of Fournier’s gangrene in Invokana users, the FDA indicating that they discovered 55 new cases of necrotizing fasciitis in diabetic patients taking SGLT-2 inhibitors. Onset for the disease ranged from a few days to over four years, so many Invokana users could still be susceptible to the deadly disease despite their current health status.
Symptoms of Fournier's Gangrene: