The Federal Trade Commission took action Friday against the three largest pharmacy benefit managers, accusing the companies of “engaging in anticompetitive and unfair rebating practices that have artificially inflated the list price of insulin drugs,

The three price benefit managers jointly administer 80% of all prescriptions in the U.S., the FTC said in the lawsuit.

The government’s antitrust watchdog on Friday sued three massive health conglomerates, accusing their drug middlemen of forcing insulin prices to skyrocket since 2012. The Federal Trade Commission claims that the middlemen — known as pharmacy benefit managers,