The U.S. FDA has stepped in to order that Johnson & Johnson add new warnings to their popular type 2 diabetes drug Invokana, saying it may significantly increase the occurrence of side effects leading to lower limb amputation.
Invokana has been on the market since March of 2013. However, the FDA didn’t recognize the danger until it was discovered inadvertently in other studies in the Spring of 2016. The manufacturer also made no warning of Invokana amputation risks until 2017.
Even when the FDA discovered ongoing studies showing increased leg and foot amputations among those taking Invokana, they couldn’t determine if it was the cause. At that time, they advised patients to continue taking their medication.
A year later, on May 16, 2017, the FDA issued a new warning, this time saying patients may face twice the risk for leg or foot amputation. They also stated Invokana was the cause of the danger.
Based on results of both the CANVAS and CANVAS-R studies, the agency ordered the manufacturer to add prominent boxed warnings for Invokana amputation risks. Now, J&J faces nearly 1,000 lawsuits from those affected.
The Invokana amputations study, known as CANVAS, was never intended to find these risks. After the release of Invokana in 2013, the FDA, concerned about reports of patient heart attacks and kidney damage, ordered two new studies to measure these risks. These were known as CANVAS and CANVAS-R.
While Johnson & Johnson hailed the results of the studies for showing lower cardiovascular (heart attack) risks among patients, these two trials had the unintended effect of uncovering the danger of Invokana amputations.
The CANVAS trials followed more than 10,100 patients from 2009 to 2017. CANVAS, designed to measure the heart attack risks of Invokana, found that 5.9 of every 1,000 patients were at risk of a leg or foot amputation. CANVAS-R, meant to measure kidney risks, found 7.5 of every 1,000 patients at risk of Invokana amputations.
These results, which were more than double the rate of patients not taking Invokana, stunned researchers and led both the European Medicines Agency and FDA to add new warnings to the drug.
Studies suggest that the higher risk of lower leg amputations among Invokana patients may be due to a worsening of diabetes-related side effects, and may be confined mostly to patients over the age of 65.
Those with type 2 diabetes are already at a greater risk of complications due to infections, nerve damage, heart disease, kidney damage and poor blood flow. The data shows an exacerbation of these problems may be why Invokana causes amputations.
Among those over the age of 65 taking Invokana, there was a greater chance of issues like foot ulcers, bone fractures, infections, restricted blood flow and resulting tissue death. In all, these factors more than doubled the risk of Invokana causing amputation.
In most cases, the amputation occurred with a toe or middle of the foot. However, some cases of severe infection or tissue death involved amputation of the leg above or below the knee.
The mechanism of injury leading to lower leg amputations in those taking Invokana is often due to a series of side effects that lead to tissue death, while hiding the dangers from the patient until it is too late for prevention.
For example, the problem often starts with a simple ulcer or sore on the foot. However, those with diabetes, and especially those taking Invokana, may be more at risk of nerve damage, causing numbness in the affected area. This may prevent early detection or treatment of the ulcer.
An untreated ulcer can easily degrade to an infection in the surrounding tissue or bone, which often leads to amputation. In fact, more than 25% of foot ulcers in those with diabetes lead to amputation.
Likewise, the higher chances for bone fracture or ischemia (reduced blood flow) may also be a mechanism of amputation injury in patients taking Invokana. Fractures that go unnoticed due to nerve damage, coupled with a loss of blood flow, can speed up infection or tissue death.
As a result, anyone with type 2 diabetes or taking Invokana is urged to conduct daily checks for injury to their feet and lower legs. Some doctors even recommend monitoring for a difference in the temperature of each foot to check for infections.
In order to prevent the onset of injuries that may lead to lower leg amputation, it is important for those taking Invokana to monitor for certain symptoms.
Doctors propose that most amputations are caused by infections that develop from untreated ulcers, bone fractures or tissue death due to restricted blood flow, all of which can be worsened in patients taking Invokana.
In order to detect problems early, and receive the necessary treatment to prevent lower leg amputation, patients should perform a daily check for the following symptoms:
Any of the above may be a sign of an undetected ulcer, bone fracture or restricted blood flow that can lead to infection or tissue death. If you are taking Invokana and notice any of these symptoms, it is important to speak with your doctor immediately.
With recent studies showing patients taking Invokana may have twice the risk of foot or leg amputation, experts are taking a closer look at other drugs in the SGLT2 class, such as Jardiance, for similar risks.
So far, there are no studies to suggest that Jardiance carries the same risks for leg and foot amputation as Invokana.
In fact, a recent review of a study conducted on Jardiance suggests there is no increased risk for amputation. In November, doctors reexamined data from the 2015 EMPA-REG cardiovascular study of Jardiance to look for signs of hospitalizations that resulted in serious treatment, and found no increase in amputations among Jardiance users.
Researchers are continuing to explore the risk of amputation among all SGLT2 drugs, However, for now, it looks to be confined to Invokana.
Last year, the FDA added warnings that the SGLT2 diabetes drug Invokana could double the risk of lower limb amputations. As a result, many patients taking the similar drug Farxiga are concerned about its dangers.
At this time, only studies on Invokana have uncovered an increased amputation risk. However, the European Medicines Agency has added warnings to all SGLT2 drugs, including Farxiga, about amputation risks.
The FDA has not required AstraZeneca, the manufacturer or Farxiga, to add box warnings for lower leg amputations. However, this could change as more research is conducted.
Based on the results of the CANVAS and CANVAS-R studies showing increased dangers of leg and foot amputation in those taking Invokana, officials with the European Medicines Agency issued a warning for all SGLT2 drugs about the risks for amputation.
As a result, all patients taking Jardiance, Farxiga, or Invokana are alerted of the potential for infections, bone fractures, restricted blood flow and tissue damage while taking these medications that may increase the occurrence of amputations.
So far, only studies of patients taking Invokana have shown a definite increase in amputations. In fact, one study, although funded and conducted by representatives for Jardiance, showed no increased amputation risk with Jardiance.
However, due to the increased chances for ulcers, nerve damage, ischemia and gangrene in those with diabetes, patients taking these drugs are urged to monitor for any symptoms that may be precursors for amputation until further testing is performed.
Patients who’ve taken the drug Invokana and been hospitalized for ketoacidosis, kidney damage or lower leg amputation have the option to file a claim against Johnson & Johnson for their damages.
So far, hundreds of Invokana amputation lawsuits have been filed in a special venue called MDL-2750, In RE: Invokana (Canagliflozin) Products Liability Litigation. With the start of trials fast approaching, reports indicate a settlement could be reached soon.
If you’ve suffered a similar injury, an Invokana amputation lawyer can discuss your case, gather the necessary records, and file a claim without you ever having to leave your home. Also, it costs you nothing unless you receive compensation.
The time to file an Invokana amputation lawsuit may be limited by the laws of your state, so it’s recommended that you speak with a lawyer as soon as possible. Contact DrugNews today to speak directly with an Invokana amputation lawyer at no cost.
Speak with a lawyer who specializes in the diabetes medication litigation.
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