U.S. regulators are poised to ban the sale of caffeine-containing alcoholic drinks amid rising safety concerns, in a blow to several small but fast-growing drinks companies.

Four Loko, Joose and other fruit-flavored, alcoholic beverages will no longer be able to contain caffeine under a series of regulatory actions expected from the Food and Drug Administration and other agencies this week, according to U.S. Sen. Charles E. Schumer (D., N.Y.) and people familiar with the matter.

Phusion Projects LLC, maker of Four Loko, the best-selling caffeinated malt beverage, said Tuesday that it would remove stimulants caffeine, guarana and taurine from its products nationally.

"We are confident that we will continue to grow our brands and remain innovative," Chris Hunter, a co-founder of Phusion Projects, said in an interview.

The company's contract manufacturers already have stopped making caffeinated versions of Four Loko, he said. Phusion is taking the step after trying unsuccessfully "to navigate a difficult and politically charged regulatory environment at both the state and federal levels," he said.