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New Studies Show Link Between Invokana and Foot or Leg Amputations

A surgeon puts on gloves before beginning an amputation procedureInvokana is a relatively new drug that’s manufactured by Johnson & Johnson’s subsidiary company, Janssen Pharmaceuticals. First approved for use in 2013 to treat type 2 diabetes, this medication has already been the subject of repeated Food and Drug Administration warnings about potentially dangerous side effects, including a recent warning about an increased risk of foot and leg amputations.

Here’s what you should know about this potentially dangerous drug, and how you can get help if you’ve been hurt by taking Invokana or other canagliflozin-containing drugs.

What Is Invokana?

Invokana is the trade name for a drug containing canagliflozin, and is used to lower blood sugar levels in type 2 diabetics. Invokamet and Invokamet XR are two drugs that also contain canagliflozin in combination with metformin, another popular drug used to treat type 2 diabetes.

Canagliflozin belongs to a class of drugs called SGLT2 (sodium-glucose co-transporter-2) inhibitors, or gliflozins. All drugs in this class generally work by preventing glucose (blood sugar) from being re-absorbed into the body via the kidneys. This means that excess blood sugar will be excreted from the body by urination, lowering overall blood sugar levels in the patient.

2017 FDA Warnings About Invokana

For a drug with such a short lifetime on the market, Invokana has a history of safety and drug information notices from the FDA. Most recently, a black box warning was issued in May of 2017 for canagliflozin-containing drugs. This is the strongest type of drug warning that the FDA issues. The black box warning forces manufacturers to place a visible safety warning regarding the issue on the prescribing information for the drug, surrounded by a prominent black-bordered box.

Based on two clinical trials called the Canagliflozin Cardiovascular Assessment Study (CANVAS) and A Study of the Effects of Canagliflozin on Renal Endpoints in Adult Participants With Type 2 Diabetes Mellitus (CANVAS-R), the FDA has determined that the black box warning is appropriate due to a risk of foot or leg amputation that’s nearly double when compared to a placebo group.

The clinical trials found that toe and mid-foot amputations were the most frequent, though both below- and above-knee amputations also occurred. In some cases, multiple amputations were necessary on one or both legs of patients taking canagliflozin-containing drugs. Infections, gangrene, ischemia, and foot ulcers were noted as the most common reasons that amputations were necessary.

A year prior to the black box warning, the FDA had issued a safety communication in May 2016 regarding the same issue, based on data from an interim study, before upgrading the warning to a black box.

Previous FDA Warnings About Invokana

The FDA released a communication to health care professionals in 2016 regarding Invokana and other SGLT2 inhibitor drugs in the same class. This warning reinforced and strengthened an earlier (2015) notice about the risk of injury to the kidneys (renal failure) while taking these types of drugs.

The FDA issued two other notices about Invokana in 2015, as well. One was a safety announcement required labeling information updates to note changes to bone density and bone strength in patients taking the drug, leading to an increase in the risk of bone fractures. The other was to note that multiple cases of ketoacidosis (DKA, or diabetic ketoacidosis) had been reported after patients started taking Invokana. DKA is a life-threatening complication that requires immediate medical intervention, or death could result.

Get Legal Help Now

If you have suffered an amputation or another injury while taking Invokana, Invokamet, or Invokamet XR, Wayne Wright LLP would like to hear from you today. We’re here to stand up for the legal rights of those who have been hurt by dangerous drugs, and we want to help you seek the compensation that you may be owed in a court of law. To arrange a free, no-obligation consultation with an experienced legal professional, call us by phone, use our contact form to send an email, or click the live chat box on this page right now.