Invokana is a prescription drug used in adults with type 2 diabetes.
As with any other drugs, some side effects are also to be expected with the use of Invokana. However, in addition to some common side effects, the problems with Invokana also extend to several dangers associated with it.
In fact:
Some side effects were so serious that many plaintiffs have filed an Invokana lawsuit.
If you are a patient with type 2 diabetes, these serious side effects and potential dangers might also be of great concern to you.
And that’s where we come in — through this article, we will help you become more informed about Invokana, its side effects, potential dangers, along with some options in taking action in case adverse reactions result.
What is Invokana used for?
Invokana (canagliflozin) is an SGLT2 inhibitor drug prescribed to lower a patient’s glucose or blood sugar levels, along with diet and exercise.
Drugs that belong to the class of medicines called sodium-glucose co-transporter 2 (SGLT2) inhibitors, where Invokana falls under, work by preventing the kidneys from reabsorbing glucose back into the blood. Instead, this excess glucose in the blood is expelled through urine.
Aside from managing blood sugar levels, Invokana is also used in certain patients with type 2 diabetes for other purposes, including:
- reducing the risk for certain cardiovascular events in adults with heart disease
- lowering the risk of complications in people who also suffer from kidney disease
According to the product’s website, the three most common side effects for Invokana are:
- genital yeast infections (in men and women)
- changes in urination
- urinary tract infections
However, these are just a few of the more commonly reported side effects of the drug. Several patients have also reported many other side effects that were not listed on the warning label of the product when it was first made available to consumers.
Dangers Associated with Invokana
Increased Risk of Amputation
Invokana was found to raise the risk of lower limb amputation. This risk earned the diabetes medication a boxed warning, which is the strictest warning issued for a drug by the FDA.
Two clinical trials (CANVAS, CANVAS-R) showed that patients taking Invokana suffered from a twofold increased risk of lower limb amputations compared to patients treated with an inactive placebo.
Most amputations were of the toe and the middle of the foot, but some amputations also involved the leg — either above or below the knee. Some patients were also reported to require more than one amputation, at times involving both limbs.
In line with this, the Invokana website also states that some factors may increase your risk of lower limb amputation, including:
- history of past amputation
- heart disease
- narrowed blood vessels
- nerve damage in the leg
- diabetic foot ulcers
Diabetic Ketoacidosis
Although considered rare, some people taking Invokana may develop a condition called diabetic ketoacidosis, which is characterized by high levels of ketones in the blood or urine.
This occurs when your body does not get glucose (sugar) for energy and instead uses fat to gain energy, leading to increased levels of blood acids called ketones.
Ketoacidosis can occur during treatment with Invokana even if your blood sugar is less than 250 mg/dL. Some of the most common symptoms of diabetic ketoacidosis include:
- nausea
- abdominal pain
- vomiting
- excessive thirst
- difficulty breathing
- frequent urination
- confusion
If you get the above-listed symptoms during treatment with Invokana, call your doctor right away. Diabetic ketoacidosis is a serious condition and can be extremely dangerous for type 2 diabetes patients.
Kidney Failure
Kidney failure is a potential side effect of Invokana.
In fact:
The first lawsuits associated with the diabetes medication were filed by plaintiffs who suffered from kidney injury while taking the drug. Two of these claims were filed in the United States, and one was filed in Canada.
Even before it was approved by the FDA, clinical trials on animals also suggested that long-term use of Invokana may contribute to kidney damage. Interestingly, after the drug was approved for use, patients taking Invokana complained of kidney problems. After they stopped taking the drug, their kidneys reportedly began working normally again.
However, it is important to note that you shouldn’t stop with your Invokana treatment unless your doctor recommends it.
Perineal Necrotizing Fasciitis (Fournier’s Gangrene)
Fournier’s gangrene is a rare yet serious bacterial infection in the area between and around the genitals and rectum. It can happen in both men and women.
Symptoms may include:
- pain, redness, and swelling in the genital or rectal area
- fever
- feeling very weak
- tiredness
People who were involved in clinical trials of Invokana didn’t acquire this rare infection. However, after the medication was approved for use, some patients reported getting Fournier’s gangrene while on Invokana or other medications in the SGLT2 inhibitors class, which means drugs that work the same way as Invokana.
More severe cases of Fournier’s gangrene required hospitalization, multiple surgeries, or even death.
Needless to say, if you think you may have developed this infection, seek medical attention right away.
The FDA on Invokana
Since Invokana was approved for use in 2013, the U.S. Food and Drug Administration has issued several public advisories about the potential risks and dangers of the drug.
Let’s have a look at the timeline of events leading up to the addition of amputation warnings on its label and the turn of events that made the FDA remove this warning.
2015 – FDA issued a warning that SGLT2 inhibitors for diabetes such as Invokana, Farxiga, and Jardiance may increase the risks of a serious condition called ketoacidosis
2016 – The agency posted a Drug Safety Communication aimed at strengthening the warnings for Invokana and Farxiga due to an increased risk of kidney damage
2017 – Amputation warnings were officially added to the drug’s label, advising that it may cause an increased risk of leg and foot amputations.
2018 – The drug got approval from the FDA to reduce the risk of combined cardiovascular injuries and death in high-risk type 2 diabetes patients
2019 – The FDA approved Invokana for lowering the risk of kidney disease, worsening kidney function, and cardiovascular death and hospitalization for heart failure in patients with type 2 diabetes and diabetic kidney disease
2020 – After reviewing data from clinical trials, the FDA removed Invokana’s boxed warning detailing its amputation risks. According to the agency, while the drug elevated risks of amputations in trials, it found on its second look that the risk was “lower than previously described,” especially when patients are “appropriately monitored.”
The FDA also said that the amputation risks no longer outweigh the drug’s benefits, now that it has been cleared in the previous years for reducing its negative effects on the heart and the kidney.
Needless to say, after Invokana got its black box warning in 2017, it saw a decline in its sales. Hence, the attempts for label expansions when its manufacturer requested approval for reducing certain risks. But just how much did this decline in sales hurt Johnson & Johnson — if it really hurt the company at all.
Invokana: Billions in Revenue
Thousands of FDA adverse event reports and lawsuits later and Invokana is still raking up big bucks for its manufacturer.
In 2016, Invokana posted sales of $1.4 billion. A year after, it got its boxed warning for an increased risk of amputations. With this, the negative connotation of the warning had its effects on Johnson & Johnson’s revenue.
From a drug that racked up almost $1.5 billion in annual sales, in 2018, sales figures of Invokana sank to $881 million. In 2019, its revenue steadily shrunk to reach just $735 million.
If you look at these figures, it is indeed evident that Invokana scores have suffered ever since the amputation warnings. However, if you think of the label expansions its manufacturer has been hanging to in order to boost Invokana sales once again, it’s very likely that this decline in sales won’t last long — with J&J fighting its way up to gain steam over its rival drugmakers, it’s very likely that we will soon again see a rise in the diabetes medication’s revenue.
Come to think of it:
Thousands of adverse event reports and lawsuits later, it seems that the FDA doesn’t plan on taking Invokana off the shelves anytime soon, and Johnson & Johnson doesn’t plan to let go of one of its best-selling products in the foreseeable future either.
