CVS Health Corp. plans to restrict the use of a toenail fungus drug from Valeant Pharmaceuticals International Inc., as part of an initiative aimed at cutting spending on dermatology treatments.

In April, the drug benefit manager will start a new program that limits the use of Valeant’s Jublia, Chief Medical Officer Troyen Brennan said in an interview on Monday. Jublia retails at about $1,000 for an 8-milliliter bottle, according to the website GoodRx, and patients in CVS’s program will have to try and fail to have their condition cured by other, less-expensive toenail fungus drugs. It’s part of a larger effort at CVS aimed at reducing the use costly dermatology drugs, Brennan said.

Dermatology drug costs “are out of control,” said Brennan. Last year, spending on Jublia grew 950 percent among CVS’s clients, Brennan said. The drug was approved by U.S. regulators in June 2014.

The program will be optional for CVS’s health insurance and employer clients. Valeant shares were down 11 percent to $75.92 at the close in New York, after two reports by an analyst Friday and Monday questioning the company’s business strategy. The stock has plunged since last August, when it hit an all-time closing high of $262.52.

A Valeant spokeswoman didn’t immediately respond to a request for comment.

Older nail-fungus medicines are “much more efficacious” than Jublia and cost far less, said Brennan. “It is a circumstance where we can go to clients and say, this is just waste we are eliminating.”

CVS’s pharmacy benefit unit manages drug plans for more than 75 million people. Brennan wouldn’t say which other drugs will be part of the new program, but said it could include additional Valeant drugs. Jublia will still be available in CVS’s retail pharmacies.

Express Scripts Holding Co., CVS’s main rival, also said in a statement Monday that it had plans to make toenail fungus drugs “significantly more affordable” for its clients.

“We are putting into place a specific plan for the toenail fungus products, and we are actively assessing the various challenges facing payers across the broader dermatology category,” David Whitrap, a spokesman for Express Scripts, said in an e-mail. Details of Express Scripts’ plan would be available in a few weeks, he said.

According to GoodRx, an online drug price comparison website, a 8-milliliter bottle of Jublia costs about $1,000, while a 4-milliliter bottle costs more than $500. By comparison, a 12-week supply of a generic version of Lamisil, another toe fungus drug, costs $20 or less at many drugstores, according to GoodRx.

Prices for dermatology drugs have been rising sharply, research has found. One study examined prices for 19 brand-name dermatology drugs and found an average price increase of 401 percent between 2009 and 2015, with most of the price increases occurring after 2011, according to results published in JAMA Dermatology this month.

In two clinical studies of Jublia, the drug completely cured toenail fungus problems in 15 percent and 18 percent of patients, according to Valeant’s Jublia website. Meanwhile, Lamisil tablets totally cured toenail fungus problems in 38 percent of patients in a separate study, according to the drug’s label. Jublia has minimal side effects, according to the drug’s website, while Lamisil has been linked to gastrointestinal symptoms, liver test abnormalities and rash.