AS A PHARMACIST, A GROWING NUMBER OF PATIENTS WILL ASK ABOUT GLUTEN in medications. Most medications don't contain gluten from wheat, barley, or rye. If they do, it's likely no more than 0.5 mg/dose, less than a serving of gluten-free food per FDA standards. But labels rarely say if medications are gluten-free and there aren't any "gluten-free manufacturers"...
Reassure patients that medications aren't a significant source of gluten. Any small amount of gluten in medications isn't likely to cause GI symptoms (bloating, gas, etc) in gluten-sensitive patients. And even some patients with celiac disease who must restrict dietary gluten to minimize GI symptoms, intestinal damage, and malabsorption may tolerate up to 50 mg/day of gluten. Expect gluten in medications to be a concern only when dietary measures aren't enough. If patients with celiac disease need to continue gluten-free medications in the hospital, follow these rules of thumb...
Don't worry about non-oral medications, only ingested gluten is a concern. Continue the patient's home medications using your non-formulary process if possible. Or if you need to switch to a formulary agent or start a new oral medication, check the product information. But you won't see the word "gluten" in labels.
Instead, look for starches or starch derivatives, pregelatinized starch, sodium starch glycolate, dextrin, or dextrate. The product may contain gluten if the source of these starches is wheat or isn't stated. Medications don't have starches from barley or rye.
The more common starches from corn, potato, rice, or tapioca, such as "sodium starch glycolate type A potato" are okay. If you call the manufacturer, don't be surprised if they can't guarantee their product is gluten-free even if the starch isn't derived from wheat for legal reasons or possible cross-contamination.
REFERENCES
-
Medications and Gluten. FDA. [online] Available at: https://www.fda.gov/drugs/ensuring-safe-use-medicine/medications-and-gluten
Leonard MM, Sapone A, Catassi C, Fasano A. Celiac Disease and Nonceliac Gluten Sensitivity: A Review. JAMA. 2017 Aug 15;318(7):647-656. Available at: https://jamanetwork.com/journals/jama/article-abstract/2648637
Catassi C, Fabiani E, Iacono G, D'Agate C, Francavilla R, Biagi F, Volta U, Accomando S, Picarelli A, De Vitis I, Pianelli G, Gesuita R, Carle F, Mandolesi A, Bearzi I, Fasano A. A prospective, double-blind, placebo-controlled trial to establish a safe gluten threshold for patients with celiac disease. Am J Clin Nutr. 2007 Jan;85(1):160-6. Available at: https://academic.oup.com/ajcn/article/85/1/160/4649352