By Michael Erman

NEW YORK (Reuters) – Prices for two dosages of the blood pressure drug valsartan rose more than any other drug in the United States in September, following a recall of much of the drug’s supply.

Chinese pharmaceutical ingredient manufacturer Zhejiang Huahai Pharmaceuticals recalled valsartan from consumers in the United States in July after finding traces of a probable carcinogen.

According to the National Average Drug Acquisition Cost (NADAC) survey for last month, prices for 160 milligram and 80 milligram tablets of the drug more than doubled last month from August rates.

The drug – the generic version of Novartis’ Diovan – has been in shortage since August, according to the U.S. Food and Drug Administration.

It was not immediately clear which manufacturers had increased their prices for the drug. Companies that are still selling versions of the drug include Alembic Pharmaceuticals, Jubilant Pharma, and Mylan NV.

The price of a 160 mg valsartan tablet rose to around 31 cents from 14 cents a month earlier, according to the survey. An 80 mg tablet cost around 20 cents on average in September, up from around 9 cents a month earlier.

The average cost of a 40 mg tablet rose around 47 percent in the month to about 19 cents.

Eric Pachman, co-founder of healthcare data firm 46brooklyn, said that the situation reminded him of the surge in pricing for hydroxychloroquine that started in late 2014 after regulatory problems hit Indian pharmaceutical company Ranbaxy Laboratories. The cost of the malaria drug rose to $2.62 a pill from 10 cents a pill in less than a year.

He said that even short-term increases in costs for a drug in shortage could affect how much some U.S. consumers pay for some time.

“If the price of valsartan jumps to $2 and then three weeks later it comes back down to 20 cents, there will be consumers somewhere in this country on high deductible plans still paying $2 a pill three years from now,” Pachman said.

Last month, the FDA halted all imports of drugs and pharmaceutical ingredients made at Huahai’s Chuannan factory.

Huahai’s English-language website indicates that the company makes more than 50 drugs, active pharmaceutical ingredients and intermediate products used in a variety of medicines to treat high blood pressure, depression and other conditions. It was not immediately clear how many of these products are made at the Chuannan plant.

(Reporting by Michael Erman, Editing by Rosalba O’Brien)