Do you have an idea of what is in these blood pressure medications? Take away the “I” from an idea and you’ve got a NDEA. That’s the chemical that seems to have contaminated certain lots of irbesartan, a type of blood pressure medication.
NDEA is short for N-nitrosodiethylamine. PubChem describes NDEA as a “synthetic light-sensitive, volatile, clear yellow oil that is soluble in water, lipids, and other organic solvents,” which is “used as gasoline and lubricant additive, antioxidant, and stabilizer for industry materials.” The description also mentions NDEA as emitting “toxic fumes” when heated to a high enough temperature and being used in the lab to cause liver tumors for experiments. Then, there is this sentence: “it is considered to be reasonably anticipated to be a human carcinogen.”
Yes, this last sentence is not written in the most definitive manner. Imagine telling your significant other, “you are considered to be reasonably anticipated to be the love of my life.” Nonetheless, it is safe to say that there are cancer-causing concerns about NDEA.
Apparently, trace amounts of NDEA have appeared in irbesartan tablets sold by Sciegen Pharmaceuticals, Inc. NDEA is not normally supposed to be part of such medications. So trace amounts would be contamination or an impurity. This impurity has prompted the company to voluntarily recalling specific lots of irbesartan tablets (USP 75 mg, 150 mg, and 300 mg dosage forms), according to the U.S. Food and Drug Administration (FDA).
Irbesartan is an angiotensin II receptor blocker (ARB). Although it sounds like a sequel to movie, Angiotensin II is actually a hormone that begins as a protein produced by your liver called angiotensinogen. Renin, a hormone produced by your kidneys, then converts angiotensinogen into angiotensin I. Next, an enzyme called angiotensin-converting enzyme (ACE) produced by your lungs converts angiotensin I into angiotensin II. Angiotensin II then may bind to receptors in your blood vessels throughout your body, causing your blood vessels to tighten. This process normally helps regulate blood flow throughout your body. However, high blood pressure can occur when your blood vessels are too narrow, which can result when vessel walls get too stiff or thickened. ARBs such as irbesartan can block these angiotensin II receptors, thus relaxing and widening your blood vessels. That is why doctors use ARBs to control high blood pressure and improve blood circulation for patients with weaker hearts.
If this seems a bit like déjà vu all over again, it “can be considered to be.” A couple months ago, the FDA had announced that Torrent Pharmaceuticals Limited was voluntarily recalling a different type of ARB, valsartan. The recall included valsartan tablets and those combined with Amlodipine and hydrochlorothiazide. In this case, the impurity was N-nitrosodimethylamine (NDMA), another chemical that “is reasonably anticipated to be a human carcinogen.” Zhejiang Huahai Pharmaceuticals had manufactured these medications.
Should you be “reasonably anticipated” to worry about this news? Note that these 2 recalls and these concerns currently only affect specific lots of blood pressure medications from specific manufacturers. It does not involve most blood pressure medications. So if you are taking another blood pressure medication or a medication that ends in “-sartan” from another manufacturer that is not listed on the FDA recall announcements, you should not be affected by these recalls. But pay attention to any subsequent recall news just in case more broader issues emerge. When you purchase medications, always keep the original bottle, packaging, and inserts. Know where your medications are coming from and who manufacturers them. After all, would you buy something described as a “luxury watch” or a “designer bag” without looking at the label and knowing who made and sold it?
What happens if you are taking irebsartan or valsartan? Check the bottle, labeling, and package inserts, and compare that information to the FDA announcements. Here is the FDA list of irbesartan products under recall as of October 29 and here is the FDA list of valsartan products under recall as of October 24. The FDA emphasizes that the ScieGen’s recall only “affects about 1 percent of the irbesartan drug products in the U.S. market.” Again, just because you are taking irbesartan or valsartan doesn’t necessarily mean that you are affected by the recall.
If there is any possibility of a match, stop taking this medication and contact your pharmacist and doctor as soon as possible. Also, keep in mind that changing one medication may change others so a real doctor should be involved in any potential medication changes.
What if you have already been taking the medications that are involved in the recall? “Trace amounts” alone may not be of huge concern, although the New Jersey Department of Health indicates on its fact sheet for NDEA, “many scientists believe that there is no safe level of exposure to a carcinogen.” The bottom line is that much remains unknown about what is a “safe” level of exposure. Yes, you shouldn’t drink gasoline or knowingly expose yourself to these chemicals. But what about chance exposures to “trace amounts”?
Answering this question can be challenging. Scientists use higher concentrations of these chemicals to induce tumor growth (in the liver, lung, and gastrointestinal tract) in animals in the laboratory. But humans aren’t rats, not in the biological sense at least. There haven’t been studies in which humans are given different levels of NDEA and tracked to see if they develop tumors (and there shouldn’t be such studies). Therefore, it is not completely clear yet how much exposure to NDEA or NDMA may lead to cancer in humans, and the threshold probably varies from person to person.
A larger concern is cumulative exposure over time. If you are repeatedly exposed to even small amounts of these chemicals or similar ones from other sources, could the effects add up? How much additional exposure will push you over the edge? Are there other ways that you are being unknowingly exposed to the chemical, assuming that you don’t work in a plastic or lubricant factory? That’s why you want don’t want such “impurities” in your medications. That’s why you should try to minimize your exposure to such chemicals in general.
These 2 recalls highlight the importance of monitoring manufacturing processes and supply chains for medications. Impurities could slip in at nearly every step in the whole chain. If you are outsourcing any part of these processes, make sure that everyone involved is following accepted guidelines and regulations. After all, finding a chemical in your medication that can “be reasonably anticipated to be a human carcinogen” and is normally found in gas, is not a gas.