Daraprim’s price skyrocketed from $13.50 to $750 per tablet and has triggered infectious disease doctors and advocates to protest its rapid price hike.

In August, a new company called Turing Pharmaceuticals purchased the rights to Daraprim and abruptly increased the price from $13.50 to $750 per tablet, that’s a 5,000 percent leap from the original Daraprim price, New York Times has learned.

Daraprim, common term for pyrimethamine, is the only medication for curing an infection acquired from cat parasites called toxoplasmosis, which can also lead to birth defects. It has also been used as a treatment for some cancers, malaria and as co-treatment for HIV infections.

CBS News reported infectious disease doctors and advocates penned a letter addressed to Turing Pharmaceuticals urging them to take a second glance at Daraprim’s price increase. The letter stated, "Under the current pricing structure, it is estimated that the annual cost of treatment for toxoplasmosis, for the pyrimethamine component alone, will be $336,000 for patients who weigh less than 60 kilograms [132 pounds] and $634,500 for patients who weigh more than 60 kilograms."

"This cost is unjustifiable for the medically vulnerable patient population in need of this medication and unsustainable for the health care system."
Daraprim’s skyrocketing price was exceptionally surprising because the drug was developed more than 60 years ago and is a non-brand name generic.

Martin Shkreli, CEO and founder of Turing Pharmaceuticals, stated that Daraprim’s price hike would affect a modest number of patients, noting that the drug is rarely used. He added that the price hike would bring Daraprim parallel with other medications for rare diseases and portion of the profits would be directed towards promoting better back-up treatments with less side effects, however, some physicians questioned his logic, as per Fortune.

Daraprim was not the only old drug that has undergone skyrocketing price increase recently. Cycloserine, a medication used in treating drug-resistant tuberculosis has increased from $500 to $10,800 for 30 pills. Valeant Pharmaceutical’s two heart medicines, Nitropress and Isuprel, also increased by 212 percent to 525 percent respectively this 2015.