The possible link between the diabetes medication Invokana and diabetic ketoacidosis has not prevented Invokana sales from increasing steadily over the two years it’s been on the market, thanks in part to a multi-million dollar promotional effort by Johnson & Johnson aimed directly at physicians.

What is Invokana?

Invokana is Johnson & Johnson’s brand name for canagliflozin. J&J also markets the same drug formulated in combination with the older diabetes medication metformin under the brand name Invokamet.

Invokana is one of a class of diabetes medications called SLGT2 inhibitors. These drugs work by allowing the kidneys to remove sugar from the blood and excrete it in urine.

As a class, these drugs have been FDA-approved for treatment of only type 2 diabetes; the FDA has not evaluated their safety or efficacy for treating type 1 diabetes.

FDA Diabetes Medication Warning

In May 2015, the FDA issued a Drug Safety Communication warning about the possible link between SLGT2 inhibitors like Invokana and reports of ketoacidosis.

The agency said that between March 2013 and June 2014 its Adverse Event Reporting System had received 20 reports of ketoacidosis in patients taking SGLT2 inhibitors. In all those cases, the patients required emergency room treatment or hospitalization.

Diabetic ketoacidosis is an abnormally high level of acidity in the blood caused by the presence of acids called ketones. It sometimes happens with prolonged fasting or abnormally low levels of insulin.

Ketoacidosis is a dangerous condition that generally requires immediate medical attention. The FDA recommends patients seek care immediately if they experience any of the following symptoms of ketoacidosis: “difficulty breathing, nausea, vomiting, abdominal pain, confusion, and unusual fatigue or sleepiness.”

The agency recommends that patients do not stop or change their medication without checking with their doctor first.

Typically, diabetic ketoacidosis is associated with type -1 diabetes, not type-2. That’s one thing that makes the FDA’s adverse event reports unusual: most of the patients reporting had type-2 diabetes.

Invokana Side Effects

Ketoacidosis is not the only possible side effect of Invokana. The FDA also mentions reports of “dehydration, kidney problems, low blood sugar when this class of medicines is combined with other prescription medicines used to treat diabetes, increased cholesterol in the blood, and yeast infections.”

Despite the risk of these possible side effects, Invokana has been popular since its entry into the market in March 2013. J&J has garnered immense success with its promotional campaign directed at the physicians in a position to prescribe Invokana.

According to analysis by Bloomberg based on date from the Centers for Medicare and Medicaid Services, in 2014 J&J spent $19.8 million on marketing Invokana directly to doctors and hospitals. The amount includes payment for things like consulting fees, speaking fees, meals, and travel expenses.

This marketing effort appears to have paid off. Sales of Invokana in the first quarter of 2015 were nearly triple what they were in the first quarter of 2014. Other manufacturers like Pfizer, Bristol-Myers, and AstraZeneca spent similar amounts promoting some of their products.

A spokesperson for J&J said marketing spending tends to be higher for drugs like Invokana while they are in their “launch phase,” as manufacturers spend more to educate physicians about the drug.