The Food and Drug Administration (FDA) has updated the labels for sodium-glucose cotransporter 2 (SGLT2) inhibitors to include the risks for ketoacidosis and serious urinary tract infections. Drugs in the SGLT2 inhibitor class include Invokana (canagliflozin), Farxiga (dapagliflozin), and Jardiance (empagliflozin).
In May 2015, the FDA issued a drug safety communication cautioning about the risk for ketoacidosis with SGLT2 inhibitors and saying the agency would continue to study this issue.
SGLT2 inhibitors are used, in conjunction with diet and exercise, to help control blood sugar in adults with type 2 diabetes. If blood sugar is not well controlled, this can lead to serious health consequences including heart disease, blindness, and nerve and kidney damage. WebMD explains that SGLT2 inhibitors help to control blood sugar by turning off the SGLT2 protein so that the kidneys can excrete blood glucose.
Between March 2013 and May 2015, the FDA received 73 reports of ketoacidosis in patients with type 1 or type 2 diabetes who were treated with SGLT2 inhibitors. Ketoacidosis symptoms include nausea, vomiting, abdominal pain, fatigue, and difficulty breathing. The condition can require hospitalization, and, if not treated, can be fatal. Patients who develop symptoms of ketoacidosis should stop taking their SGLT2 inhibitor and seek medical attention immediately, the agency said.
The FDA Adverse Event Reporting System also received reports of 19 cases of potentially fatal urosepsis and pyelonephritis that began as urinary tract infections in patients taking SGLT2 inhibitors from March 2013 through October 2014. Those 19 patients all required hospitalization, and some required intensive care unit admission or dialysis to treat kidney failure.
The new warnings and precautions in the labels of all SGLT2 inhibitors will address these safety issues and make prescribing and monitoring recommendations.
The FDA is also requiring manufacturers of SGLT2 inhibitors to conduct a postmarketing study that will analyze spontaneous postmarketing reports of ketoacidosis in patients using SGLT2 inhibitors, including the collection of follow-up data for five years.
Health care providers should assess patients taking SGLT2 inhibitors for ketoacidosis and urinary tract infections if they present symptoms that suggest either condition, the FDA advises. Patients who take SGLT2 inhibitors can develop ketoacidosis even if their blood glucose is not excessively high. If ketoacidosis is suspected, SGLT2 inhibitor use should be stopped and the individual should receive prompt treatment.
In addition to the ketoacidosis and urinary tract infection risks, the labels for Invokana and Invokamet also warn about the risk for bone fractures in those who take the drugs. A clinical trial in elderly patients showed that those who took canagliflozin for more than two years had reduced bone mineral density in their hips and lower spines, which puts them at greater risk for fracture.