The recalls stem from detection of an impurity called N-nitrosodimethylamine (NDMA) -- a probable human carcinogen -- in the valsartan active pharmaceutical ingredient (API) the affected products contain. That valsartan API has been traced back to Zhejiang Huahai Pharmaceutical Co. Ltd. in Linhai, China.
The presence of NDMA was unexpected, said the FDA, and is possibly related to changes in how the active substance was manufactured.
Zhejiang Huahai has stopped distributing its valsartan API.
It should be noted that not all products distributed in the United States that contain valsartan are being recalled -- only those that contain valsartan API supplied by Zhejiang Huahai.
The FDA said its ongoing investigation includes measuring levels of NDMA in the recalled products, assessing the possible effects on patients who have been taking these drugs, and helping the companies determine how to reduce or eliminate impurities from future drug batches.
"The FDA is committed to maintaining our gold standard for safety and efficacy," said FDA Commissioner Scott Gottlieb, M.D., in a news release announcing the recalls. "That includes our efforts to ensure the quality of drugs and the safe manner in which they're manufactured.
"When we identify lapses in the quality of drugs and problems with their manufacturing that have the potential to create risks to patients, we're committed to taking swift action to alert the public and help facilitate the removal of the products from the market.
"As we seek the removal of certain drug products today, our drug shortages team is also working hard to ensure patients' therapeutic needs are met in the United States with an adequate supply of unaffected medications."
The following companies are recalling all nonexpired lots of the products named below, which contain valsartan API supplied by Zhejiang Huahai:
"We have carefully assessed the valsartan-containing medications sold in the United States, and we've found that the valsartan sold by these specific companies does not meet our safety standards," said Janet Woodcock, M.D., director of the FDA's Center for Drug Evaluation and Research, in the release. "This is why we've asked these companies to take immediate action to protect patients."
The FDA offered guidance family physicians can pass along to patients who have been taking the affected medications.
First, because valsartan is used to treat serious medical conditions, patients taking a recalled valsartan-containing medication should continue doing so until a replacement product is acquired.
Family physicians should tell these patients to look at the drug and company names on the label of their prescription to determine whether their medication is included in the recall; if this information isn't on the bottle, they should contact their pharmacy.
If patients find they are taking one of the recalled medications listed above, they should follow the recall instructions provided by that specific company, which can be accessed via the FDA's Drug Recalls webpage.
Finally, family physicians should advise patients to contact the health care professional who prescribed the medication or the pharmacist who dispensed it if their prescription is included in the recall to discuss their treatment. This could include prescribing another valsartan product not affected by the recall or an alternative treatment option, the agency said.