A drug company on Friday announced the recall of eight more lots of irbesartan blood pressure medication after testing revealed the drugs contained trace amounts of a carcinogen.

Prinston Pharmaceuticals recalled one lot of irbesartan tablets and seven lots of irbesartan HCTZ tablets. The medication contained unacceptable levels of the probable carcinogen nitrosodiethylamine, or NDEA, the company said.

The drugs ingredients were made by Zhejiang Huahai Pharmaceuticals, a factory in China that has been linked to several recalls of commonly prescribed blood pressure drugs since July. The Food and Drug Administration has issued a warning letter and halted all new drug shipments from Zhejiang Huahai since uncovering a series of problems at the factory.

The Food and Drug Administration posted information on its website listing the blood pressure medications recalled for containing carcinogens. Here’s what to watch out for. USA TODAY

Another factory in India, Hetero Labs Limited, also has been tied to multiple recalls.

The irbesartan recall is the latest involving a large class of blood pressure drugs called angiotensin II receptor blockers, which work by blocking the effects of a hormone that narrows blood vessels. Several versions of valsartan and losartan also have been recalled since July.

Many of these commonly prescribed drugs are not part of the recall. Consumers can check the FDA’s website for a full list of recalled drugs or ask their pharmacist.

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Prinston advised patients to check with their doctor or pharmacist before they stop taking their medications. Discontinuing a recalled drug could cause more immediate harm than staying on the medication.

Prinston said the following irbesartan and irbesartan hydrochlorothiazide tablets have been recalled:

• Irbesartan, 300 mg, 90 count, lot number 331B18009, expires February 2021

• Irbesartan HCTZ, 300 mg/12.5 mg, 30 count, lot number 327A18001, expires March 2021

• Irbesartan HCTZ, 300 mg/12.5 mg, lot number 327A18002, expires March 2021

• Irbesartan HCTZ, 300 mg/12.5 mg, 90 count, lot number 327B18008, expires March 2021

• Irbesartan HCTZ, 300 mg/12.5 mg, 90 count, lot number 327B18009, expires March 2021

• Irbesartan HCTZ, 150 mg/12.5mg 30 count, lot number 325D18004, expires March 2021

• Irbesartan HCTZ, 150 mg/12.5 mg, 90 count, lot number 325B18004, expires March 2021

• Irbesartan HCTZ, 150 mg /12.5 mg, 30 count, lot number 325D18005 expires March 2021