The recall of blood pressure drugs due to valsartan impurities has reportedly resulted in a drop in the number of patients taking their medication.

A study published by Canadian researchers in November found a sharp decrease in replacement prescriptions after the valsartan recalls were initiated by Health Canada in July 2018.

Although the recalls resulted in a decrease in the number of prescriptions dispensed for recalled valsartan, one in 10 patients reportedly did not receive an alternative blood pressure medication. The researchers wrote that an “immediate increase” in emergency department visits for hypertension were seen following the recalls, along with a delayed increase in emergency department visits and hospitalization for stroke.

“It is uncertain whether the increased ED visits simply reflect excess healthcare utilization by patients seeking replacement prescriptions for their recalled valsartan, or encounters for loss of hypertension control,” researchers wrote in their article, published in the American Heart Association’s Circulation journal.

“However, these findings highlight the potential burden and risks associated with recalls of chronic oral medications used by large populations.”

When drugs are recalled, patients may stop taking their medication for a variety of reasons. Dr. Rebecca Berens, a Texas physician, told Healthline that patients may not know they can seek a replacement from the pharmacy or may not understand the reason behind the recall.

“Many patients had heard about the recalls and incorrectly believed that the medication itself was causing cancer, not understanding that this was a contaminant that is not usually found in the medication,” Berens noted.

“Some even expressed anger that their doctor had prescribed them something that causes cancer. So, I think there was definitely a large element of distrust in the medical system that contributed to this.”

Valsartan Impurities and Recalls

Valsartan recalls were initiated in July 2018 after it was revealed that certain valsartan medications contained carcinogenic contaminants such as N-Nitrosodimethylamine (NDMA). NDMA is an environmental contaminant which has been classified as a probable human carcinogen.

Although NDMA is most commonly found contaminating water and foods, the chemical can reportedly be produced in manufacturing processes. The U.S. Food and Drug Administration (FDA) has reportedly determined that the valsartan impurities were generated during the process of manufacturing the active pharmaceutical ingredient used in the blood pressure medication.

Most recalls are simple and straightforward – the products are recalled, the issue is identified, and a solution is found. However, the valsartan impurities recall has lasted over a year and continues to grow.

Originally, only valsartan was affected. Since the initial recall, the issue has been expanded to include other angiotensin II receptor blocker (ARBs) such as losartan and irbesartan. Today, over 1,000 lots of ARBs have been recalled by numerous manufacturers due to contamination.

Countless lots of the medications were reportedly affected because all of the companies sourced the active pharmaceutical ingredient from the same suppliers. Manufacturers then used these ingredients to produce the finished products, which were then either put on the market or sold to repackaging companies.

As a result, the effect of the contamination has cascaded down several supply lines and to numerous companies. A full list of the recalled ARB lots is available on the FDA’s website.