HAYWARD (CBS SF) — A dramatic overnight price increase for a decades old drug developed by a Hayward company has prompted protests from infectious disease specialists.

The rights to the drug Daraprim, developed by Hayward-based Impax were sold to startup Turing Pharmaceuticals, which is run by a former hedge fund manager.

The drug, which is popular for treating life-threatening parasitic infections increased about 5,000 percent from $13.50 per tablet to $750 after the Turing purchased the rights, the New York Times reported.

The Infectious Disease Society of America sent Turing Pharmaceuticals a letter urging the company to revise its pricing strategy.