Drug Goes From $13.50 a Tablet to $750, Overnight

The drug, called Daraprim, was acquired in August by Turing Pharmaceuticals, a start-up run by a former hedge fund manager. Turing immediately raised the price to $750 a tablet from $13.50, bringing the annual cost of treatment for some patients to hundreds of thousands of dollars.

“What is it that they are doing differently that has led to this dramatic increase?” said Dr. Judith Aberg, the chief of the division of infectious diseases at the Icahn School of Medicine at Mount Sinai. She said the price increase could force hospitals to use “alternative therapies that may not have the same efficacy.”