Hundreds of users of Invokana® (canagliflozin) and Invokamet® (canagliflozin and metformin) have filed suit alleging Janssen Pharmaceuticals, the manufacturer of these medications, failed to warn patients and their physicians of the increased risk of ketoacidosis, kidney failure, and risk of amputations.
History of Invokana
Invokana was approved by the U.S. Food and Drug Administration (FDA) in 2013 as a new treatment for diabetes. The manufacturer, Janssen Pharmaceuticals, hailed it as a breakthrough treatment for the treatment of diabetes and began a heavy marketing campaign that included not only physician marketing but also direct-to-consumer marketing in the form of television commercials and magazine ads.
Invokana was the first in a new class of diabetes drugs called active inhibitors of sodium-glucose co-transporter-2 (SGLT2 inhibitors). Essentially Invokana and other SGLT-2 inhibitors block or decrease glucose reabsorption into the bloodstream, increasing the amount of glucose flushed out of the body in urine. The less glucose absorption and more glucose passed in the urine, the lower one’s blood sugar levels.
In 2014, Janssen received FDA approval for Invokamet, a combination drug of canagliflozin and metformin.
FDA Safety Communications
In May 2015, the FDA and its counterparts in Canada and the European Union issued important warnings about the risks of diabetic ketoacidosis, kidney failure, and serious urinary tract infections.
Specifically, the FDA issued a drug safety communication after it received numerous adverse event reports of ketoacidosis and diabetic ketoacidosis in Invokana users requiring hospitalization. Diabetic ketoacidosis is a serious condition caused by a buildup of high levels of blood acids called ketones.
This condition develops when your body doesn’t produce enough insulin causing your body to break down fat for energy. Although usually treatable, the condition can be life-threatening if treatment is not sought in time. Kidney failure can occur due to the buildup of toxins in the body, such as ketones.
In September 2015, the FDA issued a safety announcement noting that the Invokana labeling was being changed to include warnings about bone density changes from Invokana use and enhanced the warning of the risk of bone fractures from Invokana or Invokamet. Bone fractures could occur as early as 12 weeks after beginning use.
In December 2015, the FDA required a label change to all SGLT-2 inhibitors to include warnings for ketoacidosis. The FDA communication also revealed reports of life-threatening blood infections (urosepsis) and kidney infections (pyelonephritis) which started as urinary tract infections.
In May 2016, the FDA issued its first safety warning regarding the risk of amputation from Invokana and Invokamet use based on the interim results of two clinical trials. Both studies indicated Invokana and Invokamet use doubles the risk of amputation, primarily of the toes.
In June 2016, the FDA issued a Drug Safety Communication advising patients and physicians of strengthened warnings regarding kidney injury risks from using Invokana and other SGLT-2 inhibitors.
Finally, in May 2017, the FDA ordered a strict “black box warning” for Invokana and Invokamet, warning of the increased risk of amputation.
The black box warning required the risk of amputation be printed at the top of the prescribing information, enclosed by a thick, black border. The warning also recommends that physicians consider the increased risk of amputation before prescribing Invokana to patients with conditions such as neuropathy, peripheral vascular disease, or a history of foot ulcers.
The mechanism by which Invokana causes amputations is not fully understood. Some doctors speculate Invokana may cause the blood to thicken and pool in the foot, leading to decreased blood flow and, ultimately, amputation.
Litigation Regarding Invokana and Invokamet
Almost 1,000 cases against Janssen Pharmaceuticals for injuries caused by Invokana and Invokamet are pending in federal and state courts across the United States. All federal lawsuits have been consolidated before a single federal Judge as part of the Multi-District Litigation process—the Hon. Brian Martinotti of the United States District Court for the District of New Jersey was assigned to oversee all federal cases.
Additional cases are pending in New Jersey, California, and Philadelphia, Pennsylvania state courts.
There are other SGLT-2 inhibitors on the market, including Farxiga (dapagliflozin), which was approved by the FDA in 2014 and is jointly developed and manufactured by Bristol-Myers Squibb and Astra-Zeneca. Jardiance (empagliflozin) and Glyxambi (empagliflozin and linagliptin) were jointly developed and manufactured by Boehringer Ingelheim and Eli Lilly.
Farxiga is also the subject of numerous injury lawsuits alleging it causes ketoacidosis, kidney failure, urinary tract infections leading to blood infections (called urosepsis), urinary tract infections leading to kidney infections (pyelonephritis), and bladder cancer. Those cases are consolidated before Judge Lorna Schofield of the U.S. District Court for the Southern District of New York.
What Are the Complications of Invokana and Invokamet?
Invokana and its chemically similar cousin, Invokamet, are linked to severe complications such as diabetic ketoacidosis, kidney failure, and amputation. Diabetic ketoacidosis is a serious condition caused by a buildup of high levels of blood acids called ketones.
This condition develops when your body doesn’t produce enough insulin causing your body to break down fat for energy. Although usually treatable, the condition can be life-threatening if treatment is not sought in time. Kidney failure usually occurs due to the buildup of toxins in the body, such as ketones.
There are also reports of Invokana and Invokamet causing life-threatening blood infections (called urosepsis) and kidney infections (pyelonephritis) that typically start as urinary tract infections. This resulted in hospitalization for treatment, and in some cases, dialysis was required.
Exactly how Invokana and Invokamet lead to amputation of the lower limbs, usually the toes, is unknown. Some doctors speculate Invokana may cause the blood to thicken and pool in the foot, leading to decreased blood flow and, ultimately, amputation.
What Is the Difference Between Invokana and Invokamet?
Invokana, approved in 2013, is a single-ingredient drug (canagliflozin), while Invokamet is a combination of two drugs (canagliflozin and metformin). Canagliflozin is the first of a new class of diabetes drugs called active inhibitors of sodium-glucose co-transporter-2 (SGLT2 inhibitors).
Invokamet combines canagliflozin and metformin, more widely known as Glucophage. Glucophage is the most commonly prescribed treatment for diabetes and belongs to a class of drugs called biguanides. Glucophage has been used as a first-line treatment for diabetes for many years.
How Do Invokana and Invokamet Work?
SGLT-2 inhibitors block or decrease glucose reabsorption into the bloodstream, increasing the amount of glucose flushed out of the body in urine. The less glucose absorption and more glucose passed in the urine, the lower one’s blood sugar levels.
Invokamet combines canagliflozin and metformin, more widely known as Glucophage. Glucophage is the most commonly prescribed treatment for diabetes. It belongs to a class of drugs called biguanides which decreases glucose production by the liver and increases the insulin sensitivity of the body tissues.
What is Ketoacidosis?
It is a potentially deadly condition by which the body’s cells cannot get the glucose needed for energy due to a lack of insulin. When the body’s cells are unable to absorb glucose into the cells, the cells will begin to break down fat and muscle for energy.
This leads to the production of ketones or fatty acids into the bloodstream, which causes the chemical imbalance known as diabetic ketoacidosis.
What About the Other SGLT-2 Inhibitor Drugs?
In addition to Invokana and Invokamet, other SGLT-2 drugs include Farxiga (dapagliflozin), jointly developed and manufactured by Bristol-Myers Squibb and Astra-Zeneca; Jardiance (empagliflozin) and Glyxambi (empagliflozin and linagliptin) which were jointly developed and manufactured by Boehringer Ingelheim and Eli Lilly.
All of these drugs are the subjects of various civil lawsuits. Farxiga is also the subject of numerous lawsuits alleging it causes ketoacidosis, kidney failure, urinary tract infections leading to blood infections (called urosepsis), urinary tract infections leading to kidney infections (pyelonephritis), and bladder cancer.