Invokana (canagliflozin) was released in March 2013 by Janssen Pharmaceuticals with high expectations from the medical world. This groundbreaking drug worked in a totally different way than existing type 2 diabetes medications on the market and was supposed to not only decrease glucose levels, but have the positive side effect of weight loss, too. However, as the old saying goes, “If something’s too good to be true, it probably is.”

Invokana causes amputations.
  • Facebook
  • Twitter
  • Pinterest
  • LinkedIn

Was Invokana Put on the Market Too Soon?

Invokana is a newer type 2 diabetes medication called a sodium-glucose co-transporter 2 (SGLT2) that helps the kidneys to flush excess glucose out through the urine rather than allowing the glucose to be reabsorbed into the body. The problem is that Invokana was not thoroughly tested before it was prescribed to millions of patients. According to Dr. Sidney Wolfe who was the director of the Public Citizen’s Health Research Group, the FDA approved Invokana based solely on how it decreased glucose levels without regard to thoroughly understanding how SGLT2 inhibitors affect the body long term. Apparently, Dr. Wolfe was correct in his hesitancy to accept this new drug based on the high expectations of Janssen Pharmaceuticals. Since Invokana entered the market, several FDA warnings have been published including:

  • Too much acid in the blood (which could lead to ketoacidosis) and serious urinary tract infections (May 2015)
  • Bone fracture risks and decreased bone mineral density (September 2015)
  • Acute kidney injuries (June 2016)
  • Increased risk of leg and foot amputations (May 2017)

Invokana Amputations

While diabetic patients are worried about the other FDA warnings against Invokana, the increased risk of leg and foot amputations have been getting the most attention. Some doctors speculate that Invokana thickens the blood and causes it to pool in the foot which leads to the increased risk for amputations. Moreover, there is clear evidence from two clinical trials that patients who take canagliflozin are twice as likely to have an amputation as those who took a placebo.

Invokana and Invokamet

While Invokana is the name most associated with SGLT2 amputations, other type 2 diabetes medications can also put patients at risk. Invokamet is Invokana and metformin (also used to control glucose levels) combined in one pill. Invokamet XR is the same as Invokamet but releases slowly in the body so patients only need to take it once a day as opposed to two times a day with Invokamet.

What Should I Do If I’m Taking Invokana or Invokamet?

Before you stop taking any medication, you should talk to your doctor first. You may want to discuss other medications that are available that don’t pose such debilitating risks or you might consider lifestyle changes that don’t pose drug risks. Additionally, diabetics have a higher chance of having an amputation than non-diabetics because of nerve damage and poor blood circulation that are associated with this disease. Check your toes, feet and legs daily to ensure that you don’t have any ulcers and if you see anything that concerns you, contact your doctor immediately.

##
Sources

“FDA Drug Safety Communication: FDA revises label of diabetes drug canagliflozin (Invokana, Invokamet) to include updates on bone fracture risk and new information on decreased bone mineral density”. FDA. Accessed January 16, 2018. https://www.fda.gov/Drugs/DrugSafety/ucm461449.htm
“FDA Drug Safety Communication: FDA confirms increased risk of leg and foot amputations with the diabetes medicine canagliflozin (Invokana, Invokamet, Invokamet XR). FDA. Accessed January 16, 2018. https://www.fda.gov/Drugs/DrugSafety/ucm557507.htm
“FDA Drug Safety Communication: FDA strengthens kidney warnings for diabetes medicines canagliflozin (Invokana, Invokamet) and dapagliflozin (Farxiga, Xigduo XR)”. FDA. Accessed January 16, 2018. https://www.fda.gov/Drugs/DrugSafety/ucm505860.htm
“J&J Drug Prevents Heart Attacks At Cost Of Amputated Toes”. Forbes. Accessed January 16, 2018. https://www.forbes.com/sites/matthewherper/2017/06/12/jj-drug-prevents-heart-attacks-at-cost-of-amputated-toes/2/#2ae716d35c07
“What are INVOKAMET® XR and INVOKAMET®?” Invokamet.com. Accessed January 16, 2018. https://www.invokamet.com/about-invokamet/what-is-invokamet
“Amputation and diabetes: How to protect your feet”. Mayo Clinic. Accessed January 16, 2018. https://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/amputation-and-diabetes/ART-20048262