The Federal Trade Commission is accusing several drugmakers of violating antitrust laws with agreements that delayed availability of cheaper generic versions of two pain treatments.

The Federal Trade Commission is accusing several drugmakers of violating antitrust laws with agreements that delayed availability of cheaper generic versions of two pain treatments.

It's the first so-called "pay for delay" case brought by the commission in which a drug's original maker agreed not to sell an "authorized generic" version until well after a generic drugmaker launched its product. That guaranteed the generic drugmakers would have no competition, and so could keep prices high, for several months.

The FTC alleges Endo Pharmaceuticals Inc., maker of Opana ER pain pills and the Lidoderm pain patch, paid Impax Laboratories and Watson Laboratories, respectively, to delay selling their approved generic versions of the products.

Endo says the FTC complaint has no merit. Impax and Watson didn't immediately respond to requests for comment.