Several drugs used to treat high blood pressure and heart failure have been recalled after officials found a cancer-causing impurity in the products.

The Food and Drug Administration issued the recall Friday, warning that the probably carcinogen N-nitrosodimethylamine, also known as NDMA, was found in several drugs containing valsartan.

According to the FDA, the presence of NDMA is these drugs was unexpected. The FDA attributes its presence to changes in how valsartan is manufactured. Not all valsartan products, however, have been recalled.

The recalled products are:

  • Valsartan by Major Pharmaceuticals
  • Valsartan by Solco Healthcare
  • Valsartan by Teva Pharmaceuticals Industries Ltd.
  • Valsartan/Hydrochlorothiazide by Solco Healthcare
  • Valsartan/Hydrochlorothiazide by Teva Pharmaceuticals Industries Ltd.

To determine if your specific medication has been recalled, look at the name of the drug and the company name on the prescription bottle label. If that information does not appear on the label, contact the pharmacy that dispensed the medication.

The FDA adds that patients taking recalled products for serious medical conditions should continue to take their medication until they have a replacement product.

Patients whose medication has been recalled are directed to contact a health care professional to discuss treatment.

“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,” said FDA Commissioner Scott Gottlieb in a news release.

The FDA continues to review this situation  and is investigating possible effects on patients taking these drugs and how companies can reduce or eliminate NDMA in future batches of medication.

Patients taking a recalled medication can follow the recall instructions provided by their medication company.  The FDA has provided instructions on their website.