Hikma Pharmaceuticals Plc's U.S. subsidiary has raised the price of a common diarrhea drug by more than 400 percent and is charging more for five other medicines as well, the Financial Times reported on Sunday.

West-Ward Pharmaceuticals, the U.S. division of London-listed Hikma, increased the prices at the start of August by between 75 percent and 430 percent, for a mean of 237 percent, according to figures seen by the Financial Times.

In the United States, generic drugmakers such as Hikma are able to dictate prices of their products that have a monopoly or face little competition, the FT said.

Among the six drugs, West-Ward is either the only U.S. supplier or one of two manufacturers.

The average wholesale price of a 60 ml bottle of liquid Atropine-Diphenoxylate, a common diarrhea drug also known as Lomotil, went from about $16 a bottle to $84, the FT reported.

Brian Hoffmann, president of U.S. generics at West-Ward, said the prices of 94 percent of the group's copycat medicine portfolio had either fallen or stayed the same in 2017, and that they had fallen overall this year.