Teva Pharmaceuticals this week expanded its recall of losartan potassium tablets after detecting a possible human carcinogen in the blood pressure medication.

The Israel-based drugmaker recalled six more lots of losartan potassium that contained unacceptable levels of a nitrosamine impurity. In April, Teva pulled 35 lots of the drug after detecting the same impurity, N-Nitroso-N-methyl-4-aminobutyric acid, or NMBA.

Teva sold bulk lots of the drug to California-based Golden State Medical Supply, which packaged and shipped the medication to pharmacies in bottles that contain 30, 90 and 1000 tablets, according to a recall notice shared by the U.S. Food and Drug Administration.

Consumers affected by the recall should continue taking their medication and ask their doctor or pharmacist about alternatives or replacement drugs. Discontinuing a medication without a replacement could cause a patient more harm than continuing the drug.