WASHINGTON The U.S. Federal Trade Commission (FTC) on Tuesday said it sent notice letters to Abbvie, AstraZeneca, Teva and other drugmakers and medical device companies disputing the accuracy or relevance of more than 100 patents listed in the U.S. Food and Drug Administration's Orange Book.

Many of the patents at issue were for devices such as asthma inhalers and epinephrine autoinjectors, the FTC said.

"Wrongfully listed Orange Book patents by pharma companies can raise drug prices for Americans, harm fair competition, and delay better drugs," FTC Chair Lina Khan said on X, formerly known as Twitter.

"Millions of Americans rely on inhalers to control their asthma. And even though some of the most popular inhalers have been on the market for decades, they can still cost patients hundreds of dollars a month," she said.

The Orange Book identifies drugs and products that the FDA has deemed safe and effective. The FTC says companies sometimes improperly list patents in the Orange Book that can delay competition from cheaper generics.

The FTC had said in September that drugmakers could face legal action if they improperly list patents with federal health regulators and said it will scrutinize any improper listings.

(Reporting by Diane Bartz and Patrick Wingrove; Editing by Bill Berkrot)