Invokana Fracture Problems, Bone Strength Risks Draw FDA Warning

Federal health regulators have announced new warnings about the potential side effects of Invokana and Invokamet, indicating that the new-generation diabetes drugs will carry stronger information about the risk of bone fractures and decreases in bone mineral density.

In a drug safety communication issued on September 10, the FDA alerted the medical community and patients that the two Johnson & Johnson diabetes drugs could cause weakening of bones in as little as three months after starting treatment.

New bone fracture warnings will be added to the “Warning and Precaution” section of the drugs’ label, and revised information will be placed in the “Adverse Reactions” section as well.

Invokana (canagliflozin) was the first member of a new class of diabetes drugs, known as sodium-glucose cotransporter-2 (SGLT2) inhibitors, which was just introduced in March 2013. Invokamet is a combination therapy, including Invokana and the front-line type 2 diabetes drug metformin.

Although the diabetes drugs have only been on the market for two years, amid aggressive direct-to-consumer promotions by the drug maker, they have already become blockbuster treatments. However, as more individuals are switched to the new drugs, information has emerged about several safety concerns, including a potential risk of diabetic ketoacidosis (DKA) and kidney failure.

Invokana Bone Fracture Side Effects

In the statement released this week, the FDA noted that there were concerns that Invokana side effects may include a risk of bone mineral density loss before the drug was even approved. However, there was only a small mention of the possibility of bone fractures from Invokana placed in the Adverse Reactions section of the drug label.

The FDA indicates that updated clinical trial data draws a more firm connection between Invokana and fractures, leading the agency to require the drug maker to strengthen the warnings provided for the type 2 diabetes drugs, which both contain canagliflozin as an active ingredient.

“The additional data confirm the finding that fractures occur more frequently with canagliflozin than placebo, which is an inactive treatment,” the warning states. “Fractures can occur as early as 12 weeks after starting the drug. In the clinical trials, when trauma occurred prior to a fracture, it was usually minor, such as falling from no more than standing height.”

The FDA also received additional information about bone mineral density loss. The agency required Johnson & Johnson to conduct a clinical trial on changes to mineral density over two years. A study of 714 elderly individuals showed that loss of bone mineral density in the hip and lower spine that was not seen in patients given a placebo.

The FDA has not yet determined whether the bone density loss and bone fracture risks also affect other diabetes medications that are part of the same class, known as sodium-glucose co-transporter 2 (SGLT2) inhibitors, such as Farxiga, Xigduo XR, Jardiance and Glyxambi.

Other Invokana Health Risks

The bone fracture warnings were announced only a few months after the FDA issued a safety communication about the potential link between Invokana and ketoacidosis problems, which is a serious diabetes complications associated with increased levels of acid in the blood.

On May 15, the FDA announced that it is investigating the potential risk of ketoacidosis from Invokana and other SGLT2 inhibitors, after at least 20 cases of were identified during the first 15 months Invokana was on the market.

All of the cases involved hospitalization or emergency room treatment due to ketoacidosis symptoms while on Invokana or a similar drug. The agency is continuing to review whether additional warnings or prescribing information are needed for the entire class of drugs.

The same month as the FDA warnings, the Institute of Safe Medication Practices (ISMP) released a report that independently evaluates adverse event reports submitted to the FDA, identifying potential safety signals involving kidney toxicity and raising questions about whether the potential Invokana risks may actually outweigh the benefits provided by the diabetes drug.

During the first year Invokana was on the market, ISMP highlighted 457 serious adverse event reports submitted to the FDA involving complications from Invokana. These adverse event reports typically only account for a small portion of the total problems associated with prescription medications on the market.

Many of the reported Invokana problems involved kidney failure, kidney impairment or problems with kidney stones, urinary tract infections, dehydration, hypersensitivity and abnormal weight loss. Looking at reports to the FDA’s adverse event reporting system, the ISMP found that Invokana received more serious adverse event reports than 92% of the other drugs regularly monitored by the group..

Since the FDA statement in May, a number of individuals nationwide are considering an Invokana lawsuit or Invokamet lawsuit after being hospitalized with ketoacidosis or diagnosed with kidney failure.

At this time, it is unclear whether potential Invokana bone fracture lawsuits may be considered in light of these new warnings.