FDA: Expanded recall of blood pressure drug valsartan may be necessary The Food and Drug Administration says "more products may need to...
The Food and Drug Administration says "more products may need to be recalled" as it investigates the presence of an impurity considered likely to be carcinogenic to humans in some generic brands of a drug used to treat high blood pressure.
The FDA informed the public July 13 that N-nitrosodimethylamine had been found in the valsartan active pharmaceutical ingredient manufactured by the Chinese pharmaceutical company Zhejiang Huahai and that three companies supplying the U.S. market were recalling some of their products as a result.
More than half of all valsartan products on the market are currently being recalled, according to its statement yesterday, and similar recalls have taken place in Europe and Canada.
The FDA describes NDMA as a "probable cancer-causing chemical found in trace amounts in water and some foods." It calls its risk to patie nts in the "affected products" as "extremely low," but its finding one that "doesn't meet FDA's safety standards."
"The initial recall has expanded to now include five manufacturers and other companies who repackage those products under a different name. More products may need to be recalled," states the release from Dr. Scott Gottlieb, FDA commissioner, and Dr. Janet Woodcock, director of the Center for Drug Evaluation and Research.
"At the same time, the FDA is working to make certain that patients have access to the treatment that they need. Currently, more than half of all valsartan products on the market are being recalled. But prescribers can find a similar replacement product within the same class to substitute for patients who require this medication."
The FDA said its risk assessment to patients is based on a four-year model - the amount of time it says it believes the "affected products h ad been on the U.S. market."
"We estimated that if 8,000 people took the highest valsartan dose (320 mg) from NDMA-affected medicines daily for four years (the amount of time we believed the affected products had been on the U.S. market), there may be one additional case of cancer over the lifetimes of these 8,000 people beyond the average cancer rate among Americans," the statement says.
"This estimate represented the highest possible level of NDMA exposure. It was a measure of the risk under the most extreme circumstances. Most patients who were exposed to the impurity through the use of valsartan received less exposure than this worst-case scenario."
The statement also indicates that the presence of NDMA as an unexpected by-product of the manufacturing of an active pharmaceutical ingredient used to make angiotensin II receptor blocker drugs like valsartan for high blood pressure and heart failure, has prompted a broader investigation, "including now testing all the products in the ARB class."
"Based on our analyses of the manufacturing processes, we are now testing all the products in the ARB class to determine if they contain NDMA," the statement reads.
"In some cases, the steps in the synthesis of other ARBs can have similarities to the synthesis of valsartan. These tests will continue until we identify all products that may contain NDMA in the ARB class, and they are no longer available in the U.S. And our robust investigation continues, as do our efforts to mitigate these risks and prevent them from recurring."
The statement notes that "NDMA's properties make it difficult to find" and that its scientists had to develop a test to "detect and quantify NDMA in valsartan API."
"We posted this method to the web to help manufacturers and regulators detect NDMA in valsartan API and tablets," the statement says.
" ;Based on information provided regarding ZHP's manufacturing processes, we believed (but did not have proof) that the impurity resulted from changes that ZHP made to the manufacturing process for its API."
It adds, "Full understanding will require correlation of multiple test results from valsartan APIs made by different processes with the various process steps used by different manufacturers or at different times. We need to determine how NDMA can be formed and why it is not separated from the API during purification.
"Once we understand the way or ways that the NDMA impurity can occur as a by-product of the manufacturing process, we will make sure these conditions are evaluated in API synthetic processes so that, in the future, testing for this impurity would be required if there was a risk of NDMA formation."
It also adds that NDMA's presence as an impurity at the suspected manufacturing level was not one anticipated.
&quo t;Because it was not anticipated that NDMA would occur at these levels in the manufacturing of the valsartan API, manufacturers would not have been testing for it."
The statement looks back to the start of the investigation.
"We identified four manufacturers using valsartan API from ZHP for the U.S. market. We contacted them to ask if they knew about NDMA in their products and to recommend recalls of affected products," the statement reads.
"In addition to ZHP, we identified 13 other API manufacturers who supply more than 20 drug companies that make valsartan for the U.S. market. We made plans to determine if their products could also contain NDMA."
Toward the end of the chronology, the FDA advises, "Because this is a continuing investigation, more manufacturers may discover that their valsartan products contain NDMA and take steps to voluntarily recall them."
"We encourage patients and prescribers to check t hese lists frequently for potential changes in the recall status of their medicine," the statement says.
"We are continuing to update this information on a regular basis and update consumers over our social media platforms to ensure broad reach."
It also refers consumers to its list of products not recalled.
Source: Google News US Health | Netizen 24 United States
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