Invokana and Invokamet Increase Risk of Leg and Foot Amputations

According to the U.S.  Food and Drug Administration (FDA), drugs Invokana and Invokamet increase the risk of leg and foot amputations among patients with type 2 diabetes.  The warnings and recent Drug Safety Communication from the FDA was based on the results of two large clinical trials.  Read on to learn more about the drugs, the dangers, and what you can do to protect yourself from these potentially dangerous drugs.

Invokana and Invokamet – Potentially Dangerous Type 2 Diabetes Drugs

Invokana and Invokamet are drugs labeled under the medication canagliflozin.  canagliflozin is prescribed to help lower blood sugar levels in adults with type 2 diabetes, in conjunction with a healthy diet and exercise routine.  canagliflozin, and thereby, Invokana and Invokamet, are classified as sodium-glucose cotransporter-2 (SGLT2) inhibitors.  The drug works by causing the kidneys to expel sugar from the body through urine.

Known side effects listed on the FDA website include:

  • Low blood pressure
  • High blood potassium levels
  • Urinary tract infections
  • Low blood sugar
  • Yeast infections
  • High cholesterol
  • Increased risk of bone breakage

In addition to these commonly warned side effects, the clinical trials titled CANVAS (canagliflozin Cardiovascular Assessment Study) and CANVAS-R (A Study of the Effects of canagliflozin on Renal Endpoints in Adult Participants with Type 2 Diabetes Mellitus) discovered that patients treated with canagliflozin drugs were about twice as likely to require a leg or foot amputation compared to their placebo-taking counterparts.  A breakdown of the findings indicated:

CANVAS trial – Risk of amputations over one year period:

  • 8 out of 1,000 patients taking placebo
  • 9 out of 1,000 patients taking canagliflozin

CANVAS-R trial – Risk of amputation over one year period:

  • 2 out of 1,000 patients taking placebo
  • 5 out of 1,000 patients taking canagliflozin

According to the studies, the most common amputations required were the toe and middle regions of the foot.  Amputations of the leg below and above the knee were also reported, along with some cases requiring amputation of more than one limb.

Factors Contributing to Amputation

The CANVAS and CANVAS-R clinical trials identified a number of factors that contributed to amputation among patients studied.  The most common precipitating factors included:

  • Diabetic foot ulcers
  • Gangrene
  • Lower-limb infections
  • Ischemia (lack of blood supply to affected body part)
  • Previous amputations
  • Neuropathy (nerve damage)
  • Peripheral vascular disease

While these precipitating factors were indicated, the recent FDA warning has been extended to all patients who have or are using canagliflozin for treatment of type 2 diabetes.

What to Do if You are Taking canagliflozin Drugs Invokana or Invokamet

The FDA Drug Safety Communication about canagliflozin recommends patients consider the following when taking these medications:

  • Before starting any medication, talk to your doctor about the risks, benefits, and potential side effects. Ask questions and get answers before starting any new medication.
  • Contact your doctor immediately if you develop pain, tenderness, ulcers, sores, or infections in your feet or legs.
  • Each time you fill a prescription for medications containing canagliflozin, read the Medication Guide to see if there are changes to the side effects or patient safety information.
  • Do not stop taking medications containing canagliflozin unless directed by your doctor. Stopping your medication could cause your blood sugar to become uncontrolled.  Uncontrolled blood sugar levels can lead to serious health risks, such as kidney or nerve damage, heart disease, or blindness.
  • If you are taking a medication containing canagliflozin and experience adverse side effects, report your experience via the FDA MedWatch program.

Patients who have suffered adverse side effects from medications containing canagliflozin may find it helpful to speak to a medical malpractice attorney to learn more about patient rights, the importance of healthcare providers informing patients, and how to get help after being harmed by a dangerous medication or medical error.

Information for Doctors

Doctors are tasked with reviewing a number of factors prior to prescribing any medication.  They must base their decisions on information, the patient’s medical history, and a thorough review of the benefits and risks.  Before prescribing medication containing canagliflozin, the FDA recommends doctors consider the following:

  • Carefully review the patient’s history and identify if there are any factors that may predispose them to an increased risk of amputation, such as neuropathy, prior amputations, or diabetic foot ulcers.
  • Consistently monitor patients who take canagliflozin for symptoms of infection, ulcers or sores, or pain or tenderness. If such complications occur, it may be best to stop using canagliflozin.
  • Inform and educate patients on recognizing symptoms that may increase their risk for amputations. Urge patients to seek prompt medical attention should these signs or symptoms become apparent.
  • Urge patients to read the Medication Guide associated with canagliflozin when they pick up their prescription.
  • Report any adverse side effects through the FDA MedWatch program.

Get Answers to Your Questions about Potentially Dangerous Drugs

As a patient, you trust your doctor to give you the best advice and care possible.  Unfortunately, that doesn’t always happen.  When the FDA releases a Drug Safety Communication, there are guidelines for healthcare providers, patients, and retailers.

There is a great deal of power in information.  Unfortunately, an FDA warning does not always mean that a doctor will stop prescribing medication, or that a patient will get the information needed to recognize risks and get alternate help.  Learn more about your legal rights as a patient, and what you can do if you have been harmed by a dangerous drug by calling Brown & Brothers today.  Fill out our online form to get started getting the answers you need.

 

Sources:

https://www.fda.gov/Drugs/DrugSafety/ucm557507.htm

https://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm558605.htm?source=govdelivery&utm_medium=email&utm_source=govdelivery

http://www.diabetesincontrol.com/fda-black-box-warning-amputation-risk-for-canagliflozin/