WASHINGTON — The Food and Drug Administration is voluntarily recalling several drugs used to treat high blood pressure and heart failure that contain the ingredient valsartan.

The recall comes because an impurity, known as NDMA, was found in the recalled products. NDMA is known to cause cancer, the FDA said.

The agency said the presence of NDMA was unexpected and thought to be related to changes in the way the ingredient, valsartan, was manufactured.

The recalled products include valsartan produced by Major Pharmaceuticals, Solco Healthcare and Teva Pharmaceuticals.

The FDA has a specific list of impacted medications on its website.

The FDA said patients with the recalled products should contact their doctor and their pharmacist if their medication is included on the recall list.

The agency said it is continuing to investigate NDMA levels in the medicine and assessing the possible effect on patients who took the medicines.