Torrent recall, Dr Reddy's distribution halt add to cracks in global drug supply chain

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Regulators and drugmakers are taking different actions as the discovery of more suspected carcinogens are turning up in the global drug supply. (Pixabay)

Interruptions continue to wreak havoc on the global drug supply as drugmakers respond to the detection of impurities that are produced during manufacturing of some commonly used prescription and over-the-counter meds. 

India’s Dr. Reddy’s joined Sandoz by halting worldwide distribution of its generic versions of the OTC heartburn med Zantac, India’s BusinessLine reports. The actions were taken after the FDA learned that the suspected cancer-causing impurity N-nitrosodimethylamine (NDMA) was being formed during the manufacturing of ranitidine drugs.

RELATED: Novartis doesn't wait for FDA investigation and halts distribution of its generic Zantac 

On top of that, India’s Torrent Pharmaceuticals expanded its voluntary recall of losartan potassium tablets after it determined that five lots made with an API from Hetero Labs had another but similar impurity, N-Nitroso-N-methyl-4-aminobutyric acid (NMBA), at levels above the FDA standard of 9.82 parts per million. That recall included three lots of losartan potassium tablets and two lots of losartan potassium/hydrochlorothiazide combination tablets.

The global recalls began more than a year ago when regulators first determined that NDMA was showing up in valsartan blood pressure meds made with an ingredient from China. It figured out that impurity can be created during sartan drug manufacturing under certain conditions. 

With further testing, scientists found that two other impurities, NMBA and N-Nitrosodiethylamine, were also being created in some situations. That extended the recall to some irbesartan and losartan drugs, even leading to shortages of losartan. The FDA has said the risk for patients stopping their blood pressure meds is greater than the risk of getting cancer and urged them continue while it determined how to handle the discoveries.

RELATED: Teva recall: Tainted blood pressure drugs continue to show up in U.S. supply

The agency issued new testing requirements and set standards for the impurities. It appeared more recently that the recalls were coming under control. Then, two weeks ago, the FDA announced NDMA has been discovered in ranitidine medicines like Zantac.

Again, it said it was working with regulators in other countries to determine the source of the tainted ingredient and has yet to determine whether the amount of the impurity in the drugs poses any kind of serious risk to consumers; the agency said it appears to be small.

But other regulators, including Canada, acted more affirmatively and asked drugmakers to quit distributing the drugs until the risks were better known. That led Novartis’ Sandoz unit and now Dr. Reddy’s to go ahead and halt distribution worldwide. Sanofi, maker of the branded Zantac, on the other hand, has said that because the risks seem so small, it is not halting distribution except in Canada.