TRENTON, N.J. — After weeks of criticism from patients, doctors and other drugmakers for hiking a life-saving medicine’s price more than fifty-fold, Turing Pharmaceuticals is reneging on its pledge to cut the $750-per-pill price.

Instead, the small biotech company is reducing what it charges hospitals, by up to 50 percent, for its parasitic infection treatment, Daraprim. Most patients’ co-payments will be capped at $10 or less a month. But insurers will be stuck with the bulk of the $750 tab. That drives up future treatment and insurance costs.

Daraprim is a 62-year-old pill whose patent expired decades ago. It’s the preferred treatment for a rare parasitic infection, toxoplasmosis, which mainly threatens people with weak immune systems, such as HIV and organ transplant patients, and pregnant women, because it can kill their baby.

Dr. Carlos del Rio, chairman of the HIV Medicine Association, called Turing’s changes “just window dressing.”

Turing’s move comes after a pharmacy that compounds prescription drugs for individual patients, Imprimis Pharmaceuticals, started selling a custom-made version for 99 cents per capsule. Those sales weren’t a factor in Turing’s pricing strategy, chief marketing officer Nancy Retzlaff said Wednesday.

Del Rio noted that while hospitals treat many patients initially, most are then treated at home for a couple months, so the lower hospital price doesn’t help.

“This medication can be made for pennies. They need to reduce the price to what it was before,” he said.

Turing, with offices in New York and Switzerland, bought U.S. rights to sell Daraprim in August, when it had no competition. Daraprim is one of numerous old drugs with limited competition whose makers have raised prices sharply.