The question of Invokana amputation risk is the cause of action in a growing number of injury lawsuits against drug maker Janssen Pharmaceuticals, a subsidiary of health care products giant Johnson & Johnson.

According to a 2016 warning published by the U.S. Food and Drug Administration, taking the diabetic drugs Invokana and Invokamet can substantially increase the risk of lower limb amputations. Plaintiffs filing complaints against Janssen and its parent company claim that they failed to adequately warn patients and about the amputation risk.

If found liable, these companies could wind up paying substantial amounts of money for patients who now suffer permanent disability.

What Is Invokana/Invokamet?

Invokana (canagliflozin) is part of a class of prescription diabetic medications known as Sodium Glucose Co-Transporter 2 (SGLT-2) inhibitors. Prescription drugs in this class operate on a specific protein found in the kidneys that play a significant role in maintaining blood glucose levels. SGLT-2 normally helps the kidneys in the reabsorption of glucose, which is then released back into the bloodstream.

Drugs such as Invokana and Invokamet prevent this process from taking place. As a result, excess glucose is passed out of the body through the urine. Other commonly-prescribed drugs in this class include Farxiga (dapagliflozin), Jardiance (empagliflozin) and Steglatro (ertugliflozin).

Invokana Amputation and Other Side Effects

Ironically, Invokana and Invokamet have been found to cause some of the same problems they were developed to prevent. In addition to Invokana amputation, the product has also been linked to ketoacidosis, a life-threatening condition commonly associated with diabetes in which blood pH levels become dangerously low (acidic).

Other serious adverse effects linked to Invokana include urinary tract infections, yeast infections of the genitals, increased levels of LDL cholesterol, and hypotension (blood pressure of less than 90/60). In rare cases, Invokana may lead to cardiovascular problems.

Invokana Risks and Statistics

An independent analysis of the Canagliflozin Cardiovascular Assessment Study (CANVAS) found that out of every 1,000 patients who took 100 milligrams per day over the course of 12 months, seven would wind up having an Invokana amputation. That analysis also found that twice as many patients experienced amputations when they took Invokana as those who were given a placebo.

Because of the amputation risk, the FDA has required a “black box” warning to appear on all packages of Invokana and Invokamet.

It is inadvisable to discontinue taking any medication without consulting a physician first. Patients are advised to consult a health care professional as soon as possible if they notice any of the following symptoms:

• unusual pain or tenderness in the legs or feet
• sores or skin ulcers that do not heal
• infections

Any of these symptoms may indicate a risk for an Invokana amputation.