The term “gluten-free” now adorns the shelves of grocery stores, health foods stores, and pharmacies. Gluten is an insoluble protein that is naturally found in grains such as wheat, barley, and rye and gives bread products the chewy texture.1 Avoidance of gluten has always been a reality for those with celiac disease but is now becoming a mainstream idea as many individuals discover that they have non-celiac gluten sensitivity or that they simply feel better when consuming less gluten.2 While the number of those affected by gluten intolerance or sensitivity is not accurately known, the prevalence of true celiac disease is about 1% worldwide.2, 3
Celiac disease is an autoimmune disorder that has a genetic component and an environmental component. A cell-mediated immune response results in inflammation of the small intestine and causes atrophy of the villi on the internal surface of the intestine. Atrophy of the intestinal villi disrupts absorption of nutrients and can cause weight loss, muscle wasting, chronic diarrhea, and abdominal discomfort.3 The environmental trigger for inflammation has been determined to be gluten found in wheat and grain products.4 For people living with celiac disease, avoidance of gluten is essential to controlling the inflammatory symptoms.3, 4
While it is largely known that food products made from wheat or other grains likely contain gluten, there is less widespread discussion about the presence of gluten in medications. Tablet and capsule dosage forms of medications contain the active ingredient and various excipients. Excipients, or “fillers”, are inactive ingredients that are added to the medication in order to aid in the delivery of the dosage form.5 This includes, but is not limited to, adding bulk, adjusting pH, increasing solubility, delaying absorption, flavoring, coating, coloring, sweetening, and preserving. Several excipients are derived from plant sources and have the potential to contain gluten. While gluten contamination in drugs is often trace, even a small dose of 30-50mg of gluten has been associated with symptoms in patients with celiac disease.6
Generic medications are often produced by more than one manufacturer, and the excipients in different products may or may not be the same. When evaluating medications for gluten, the most important ingredient to pay attention to is starch. While most sources of starch in medications are corn, potato, and tapioca, which are all gluten-free sources, starch can contain wheat that could potentially contaminate the medication with gluten.5 If the source of the starch is not identified (e.g. listed as “starch” or “pregelatinized starch”), further investigation is necessary. Pharmaceutical manufacturers maintain information about the ingredients that are used to manufacture their products. When contacted, they will disclose the source of the starch and will often verify if a product has been determined gluten-free (through product analysis by the manufacturer, not FDA-certified).
The four “Dex-ingredients” that may be present in medications are starch derivatives and are dextrose, dextrans, dextrates, and dextrins. Dextrose and dextrans are derived from corn and potato starches and are not sources of potential gluten contamination. Dextrates and dextrins, however, can be derived from any starch source, and the only certain way to guarantee the absence of gluten is to contact the pharmaceutical manufacturer. Fructose, cellulose, gelatin, povidone, and lactose are other common excipients that do not contain gluten and should not warrant investigation.5
Celiac patients who are highly motivated can investigate the medications that they take to determine the presence of gluten. Also, the patient’s community pharmacist can review the products available in his or her pharmacy and modify inventory, based on the patient’s needs and the financial and logistic practicality of obtaining gluten-free medications. Several online resources exist for both patients and pharmacists to investigate a medication’s ingredients.6 Clinical Pharmacology©, a subscription-based drug database, contains a product comparison report tool that lists all of the excipients in a specific drug product, based on manufacturer and National Drug Codes (NDC). The ingredient list can be reviewed to determine the potential for gluten contamination, and the manufacturer can be contacted if ingredient sources are not specified. Additionally, medication package inserts list product ingredients and are often published online by the drug manufacturer.5
Another online resource that can be helpful to patients and to pharmacists is www.glutenfreedrugs.com. This website is maintained by a clinical pharmacist at Nationwide Children’s Hospital (Columbus, OH) and contains lists of medications that are gluten free, sorted both alphabetically and by therapeutic category. The lists include over-the-counter (OTC) products and differentiate the product manufacturer for generic drugs.7 The Gluten in Medicine Identification Act of 2012 (H.R. 4972) was introduced to Congress in April 2012. The bill proposed “to amend the Federal Food, Drug, and Cosmetic Act to require the label of drugs intended for human use to contain a parenthetical statement identifying the source of any ingredient constituting or derived from a grain or starch-containing ingredient”.8 The bill, however, was not enacted, and no legislation currently exists that mandates the labeling of gluten presence in medications.7, 8 Because of this fact, the best way to determine if gluten may be a contaminant in a medication product is to investigate the ingredients of the product and to contact the manufacturer for verification of gluten-free status.
Mary Naeger, Pharm.D. Candidate, 2015
St. Louis College of Pharmacy
- Lee HJ, Anderson Z, Ryu D. Gluten contamination in foods labeled as “gluten free” in the United States. J Food Prot [Internet]. 2014 Oct [cited 2014 Nov 5]; 77(10):1830-1833. PMID: 25285507.
- Manseuto P, Seidita A, D’Alcamo A, Carrocio A. Non-celiac gluten sensitivity: Literature review. J Am Coll Nutr [Internet]. 2014 Feb [cited 2014 Nov 5]; 33(1):39-54. PMID: 24533607.
- Mavrinac MA, Ohannessian A, Dowling EP, Dowling PT. Why celiac disease is so easy to miss. J Fam Pract [Internet]. 2014 Sep [cited 2014 Nov 5]; 63(9):508-513. PMID: 25353024.
- Anderson WH, Mackay IR. Gut reactions—from celiac affection to autoimmune model. N Eng J Med [Internet]. 2014 Jul 3 [cited 2014 Nov 5]; 371(1):6-7. PMID: 24988553.
- Plogsted S. Medications and celiac disease—tips from a pharmacist. Pract Gastroenterol [Internet]. 2007 Jan [cited 2014 Nov 5]; 31(1):58-64. Available from http://www.medicine.virginia.edu/clinical/departments/medicine/divisions/digestive-health/nutrition-support-team/nutrition-articles/PlogstedArticle.pdf
- King AR, University of Kansas Drug Information Center Experiential Rotation Students, August 2012. Gluten content of the top 200 medications: Follow-up to the influence of gluten on a patient’s medication choices. Hosp Pharm [Internet]. 2013 Oct [cited 2014 Nov 5]; 48(9):736-743. PMID: 24421547.
- Plogsted S. Gluten Free Drugs [Internet]. Columbus, OH; [updated 2014 May 12; cited 2014 Nov 5]. Available from http://www.glutenfreedrugs.com/
- Gluten in Medicine Identification Act of 2012, H.R. 4972, 112th Cong., 2d Sess. (2012).