The FDA approved the drug Invokana for use in those with Type 2 diabetes in March, 2013. While this was the only approved use for Invokana, it appears the drug may have been promoted for off-label use, specifically for weight loss. One Invokana advertisement claims a “secondary endpoint of greater reductions in body weight.” For a variety of reasons, this off-label promotion may well become a factor in the liability analysis of future Invokana cases. In order to understand the issues with promoting Invokana for weight loss, it is necessary to understand just how the drug works.
How SGLT-2 Inhibitors Work in the Body
Most diabetics in the United States are Type 2 diabetics which means the body does not produce enough insulin to properly metabolize the sugars being put into the body. This can result in weight issues as well as a condition known as insulin resistance. Those with Type 1 diabetes (also known as juvenile diabetes) can experience excessive thirst and frequent urination, and may shed large amounts of weight when they develop a condition known as ketoacidosis. This condition occurs when the body is unable to metabolize sugar, making it a toxin in the bloodstream. Because the body cannot metabolize the sugar, it attempts to excrete as much as possible, depleting the volume of the body as water is pulled from the cells. In effect, the body cannibalizes itself.
SGLT-2 inhibitors, such as Invokana, work in somewhat the same way; instead of metabolizing blood sugars, like insulin or older diabetic drugs do, the SGLT-2 inhibitor blocks reabsorption of the glucose after it passes through the kidneys. The SGLT-2s use the kidneys in what many consider an unnatural manner by helping the body excrete sugar through urination. In other words, Invokana allows high amounts of blood sugar to enter the kidneys, blocking the reabsorption process so the blood sugar is not being recycled, after it has gone through the kidneys. This process can lead to diabetic ketoacidosis, meaning the patient may, in fact, lose weight, but through an unnatural and potentially dangerous process.
Public Citizen Condemns Off-Label Marketing of SGLT-2 Inhibitor Drugs
A letter written by consumer advocacy group, Public Citizen, urged the FDA to fine Janssen Pharmaceuticals as well as AstraZeneca and other drug manufacturers for off-label marketing of their Type 2 diabetes drugs. The letter accuses the FDA of failing dismally to oversee such matters. Five direct-to-consumer advertisements for five different drugs were targeted in the letter, including: Janssen’s Invokana, Novo Nordisk’s Victoza, Boehringer Ingelheim’s Jardiance and AstraZeneca’s Farxiga and Bydureon.
While none of these drugs have been approved to help patients lose weight, the advertisements convey to consumers and doctors that the drugs have been deemed safe and effective for weight loss. Because all of the five drugs listed have been associated with serious potential side effects, Public Citizen believes the advertisements promoting weight loss skewer the risk-benefit calculations made by physicians and consumers. In fact, while not approved for weight loss efforts, all five drugs have FDA-approved labels in which weight loss benefits are indicated in the fine print. In response, Janssen stated its claims regarding weight loss and lower blood pressure had the FDA’s blessing. The FDA has not confirmed or denied Janssen’s statement.
Other Dangers Associated with Invokana
In addition to potentially causing dangerous ketoacidosis, Invokana has been associated with heart attack, stroke and kidney failure as well as increasing both LDL and HDL cholesterol levels and causing frequent urinary tract infections. Kidney failure is a serious complication linked to Invokana use. Since kidney damage is already associated with diabetes, adding a drug which can cause further kidney damage may not be a wise choice. Kidney damage and kidney failure can result from ketoacidosis, therefore if Invokana triggers ketoacidosis, kidney damage or kidney failure may be a byproduct.
Did Johnson & Johnson and Janssen Exhibit a Failure to Warn?
Invokana works by essentially blocking normal kidney function, therefore some experts have suggested the link between Invokana and renal failure should have been known before the drug was marketed. This may mean that future lawsuits will apply the failure to warn laws on behalf of plaintiffs harmed by Invokana or other SGLT-2 inhibitor drugs.