Mobile menu

Inactive ingredients in drugs may contain gluten

March 25, 2019

Inactive ingredients in drugs may contain gluten


Celiac disease research needs you!

Opt-in to stay up-to-date on the latest news.

Yes, I want to advance research
No, I’d prefer not to
Don’t show me this again

Study highlights some dangers for those who have celiac disease

By Amy Ratner, Medical and Science News Analyst

A celiac disease patient who developed symptoms after taking medication in a capsule made with unlabeled wheat starch prompted a Boston gastroenterologist to investigate inactive ingredients in drugs.

Overall, the resulting study by Giovanni Traverso, M.D., of Brigham and Women’s Hospital and colleagues at Massachusetts Institute of Technology (MIT), concluded that the majority of oral medications contain ingredients that could cause allergic or gastrointestinal reactions in some people who have allergies or intolerances. This includes celiac disease patients who have to follow a gluten-free diet and must avoid wheat, barley and rye,

Wheat starch in drugs

The study found that the number of medications made with gluten-containing wheat starch was relatively small, less than one-half of one percent. But lack of labeling magnifies the consequences for those who have celiac disease and have difficulty determining when wheat starch is used in a drug. The study did not include ingredients made from barley in its list of critical inactive ingredients that can act as allergens, but barley can sometimes be used in medications, too.

Learn more: Gluten in medications

“For patients suffering from celiac disease, it’s important to review anything that they are ingesting as even medications and supplements can contain wheat-derived products,” noted Traverso, who is also a biomedical engineer at MIT.

The presence of gluten in medications is so tricky that Traverso said he could only describe the patient behind the study as “potentially being glutened” since the actual gluten content of the capsule could not be verified.

The study, published in the journal Science Translational Medicine, pointed to research from a 2013 study that found 18 percent of drug manufacturers indicated their medications contain gluten. Additionally, 69 percent of manufacturers claimed to produce gluten-free products, but only 17 percent tested their product and could provide documentation.

Based on an earlier Beyond Celiac survey, researchers at Digestive Disease Week in 2017 reported that many celiac disease patients worry significantly about the risk of gluten in medications. Fifty four percent of nearly 5,500 surveyed reported always checking their medication for gluten-containing ingredients and 38 percent said they have had a reaction to gluten in medications.

Read more: Worry about gluten in medications

The Food and Drug Administration (FDA) is looking into adding gluten content to drug labels, the oral medications study notes. However, the FDA proposal would make gluten labeling voluntary, and Beyond Celiac is working to make the labeling requirement mandatory.

Read more: How Beyond Celiac is working for safer gluten-free medications

Allergic reactions

The current study identified 38 inactive ingredients that could cause allergic reactions in those sensitive enough to react to small amounts. Lactose is the most frequently used and is found in nearly 45 percent of oral medications. Adverse reactions can both affect a patient’s wellbeing and result in reluctance or failure to take a prescribed drug, the study says.

Oral medications are made of active ingredients and inactive ingredients. The active ingredient produces the intended effect of a drug, while inactive ingredients, also referred to as excipients, are used to hold pills and capsules together and to improve absorption, stability, taste and appearance. Traverso and his colleagues determined that inactive ingredients make up about 75 percent of the average medication.

The study analyzed the Pillbox database, which contains information on about 42,000 medications. Researchers found that the average tablet or capsule contains about nine inactive ingredients, but some contain 20 or more.

On average, the study said, 82 formulations are available per active ingredient for the 18 most frequently prescribed oral medications in the United States. This highlights how many versions of the same medication are available, the authors wrote.

Varying inactive ingredients presents challenge

Variations in the use of inactive ingredients is a challenge for celiac disease patients who have to check for gluten each time a prescription is filled. Often, the doctor and pharmacist don’t know whether an active ingredient contains gluten. And the information can be difficult to get from drug makers.

The study also notes that for patients who take multiple medications every day, there may be an additional impact. Nearly 40 percent of Americans older than 65 take at least five prescription medications daily, the authors write, and the cumulative amount of gluten or an allergen could be an issue of special concern for older adults.

The study was published here.



Think you may have celiac disease?

Symptoms Checklist