Johnson & Johnson’s subsidiary company, Janssen Pharmaceuticals, is being sued by a Philadelphia man who claims the diabetes drug, Invokana, damaged his kidneys. Invokana has been on the market for two years, and has been widely prescribed. Two months ago, however, the Food and Drug Administration (FDA) determined it causes “too much acid in the blood and serious urinary tract infections,” and required a warning label on the drug’s packaging.

The warning applies not just to Invokana, but to a whole class of diabetes drugs called SGLT2 (sodium-glucose co-transporter) inhibitors. These medications work by preventing sugar from being reabsorbed into the bloodstream. The warning states that the drugs may cause ketoacidosis, a serious condition which can result in diabetic coma and even death.

Other complications have also been seen in patients taking Invokana. In 2015, reports said the drug could increase risk of kidney problems, including “kidney failure or impairment, dehydration and fluid imbalances, kidney stones, urinary tract infections and abnormal weight loss.” In 2013, Invokana was implicated in yeast infections among patients, as well as decreased bone density that caused frequent bone fractures.

Arthur Portnoff filed his lawsuit against the pharma giant only days after the FDA posted its official warning. His lawsuit alleges he suffered ketoacidosis, resulting in hospitalization. Portnoff is a type 2 diabetic, and he began experiencing adverse health effects after taking the drug for a few months. He says Janssen brought the drug “to market without conducting sufficient studies to assure its safety to patients.” According to the publication, Lawyers and Settlements:

Not only does Portnoff accuse Janssen of not alerting consumers to the risk, he also accuses Janssen of withholding information about the risk for diabetic ketoacidosis and Invokana adverse events from regulators.

There are a number of other lawsuits pending, as well. William C. Counts of Illinois is suing Janssen Pharmaceuticals, Johnson & Johnson and Mitsubishi Tanaba Pharma Corp. over Invokana, saying the drug cause him severe kidney damage. He has asked for $75,000 in restitution for “product liability, defective design, failure to warn, negligence, fraud, misrepresentation, and breach of warranties.”