CARSON CITY, Nev. — A Republican lawmaker in Nevada revived an attempt to impose price controls on insulin with a proposal Monday aimed at reining in prescription drug market middlemen.

Senate Minority Leader Michael Roberson proposed the state require middlemen to disclose insulin rebates they get from drugmakers and the rates they charge insurers for the same products.

Under the proposal, pharmacy benefit managers, contracted by insurers to negotiate favorable drug prices, would have to pass onto insurance companies at least 80 percent of the insulin discounts that drugmakers give them.

“I am confident, if we ensure that more of those rebates get to the insurance providers, that those rebates will be reflected in the price — the premium and the deductibles — that Nevada consumers pay,” Roberson said.

Benefit managers would also be outlawed from using what Roberson calls a “gag rule” to keep pharmacists from telling patients about alternate or less-expensive prescriptions.

Additionally, the measure would require pharmaceutical companies to publicly justify any insulin price hikes greater than annual inflation, drawing on a similar law passed last year in Vermont.

His proposal goes further than a Democratic effort to tackle the increasing insulin costs faced by people with diabetes, but Roberson’s late-session bill could be doomed by opposition from a pivotal member of the Democratic majority with a competing bill.

Democratic Sen. Yvanna Cancela’s bill would require pharmaceutical companies to annually turn over insulin prices before negotiating discounts. It has passed two committees and is moving to the Senate floor for a full vote.

Justification of prices is meaningless if drugmakers aren’t also forced to disclose those prices, Cancela said.

The Democratic bill initially sought to mandate that drugmakers refund insurance companies and patients for insulin price increases greater than inflation, but Cancela deleted that provision after legislative attorneys questioned its legality.

Roberson said the same attorneys have made no such warnings about his measure.

Cancela’s bill enjoys support from the controlling party at the statehouse. She said Monday that Roberson’s plan to “arbitrarily” shackle pharmaceutical pricing contracts is “troubling” and said she needed more time to consider other provisions of his bill to decide whether to potentially support or add them to her own measure.

“I’m going to do my research and do my best to understand the different provisions of this bill and see if any of them help address the problem I’m trying to solve, which is the lack of transparency in drug pricing and the exceedingly high cost of insulin,” Cancela said.