Patients with celiac disease or who otherwise follow a gluten-free diet need to be aware of potential sources of gluten, especially in medications such as oral contraceptives. The FDA defines gluten as “proteins that naturally occur in [wheat, barley, and rye or their crossbred hybrids] and that may cause adverse health effects in persons with celiac disease”. Potential sources of gluten can come from excipient ingredients, which are used to bind pills. Starches used in excipients are typically derived from corn, potato, rice or tapioca which don’t contain gluten, but some starches may also be derived from wheat.

Besides the type of starch, the amount of starch in a pill can vary. While the FDA strictly regulates the active ingredients of drug products, drug manufacturers are allowed to use any quantity and type of FDA-approved excipient. Another factor to consider is that generic products only require the active ingredient to be identical to the brand and do not have to use the same excipient or inactive ingredients. So while a brand name medication may be gluten-free, the generic formulation isn’t guaranteed to also be gluten-free.

Determining if a Medication is Gluten-Free

If you’re looking for what ingredients are included in a medication, you can find them listed on the package insert, also known as the prescribing information. If the ingredients listed on the package insert don’t include what source they are derived from, such as ‘starch’ instead of ‘cornstarch’, then you should call the manufacturer to confirm the source.

Examples of both gluten-free and gluten-containing excipient ingredients include:

• Pregelatinized starch, sodium starch glycolate: derived from corn, potato, rice, or wheat but chemically processed so gluten remaining is unlikely
• Dextrans, dextrose: derived from corn and potato starch so they do not contain gluten
• Dextrates, dextrins: derived from any starch source so you would have to call the manufacturer to confirm if gluten is included
• Starch alcohols (xylitol, maltitol, and mannitol): some are derived from wheat but they are purified to no longer contain gluten

Another issue that can arise is cross-contamination. The FDA has stated that although they don’t collect data in regards to contamination with gluten, “the amount of gluten would be well below the levels we have estimated an inactive ingredient, such as wheat starch, could potentially contribute to an oral drug product”. If wheat happens to be an impurity in a drug listed as gluten-free, the FDA estimates that it could contain no more than 0.5 mg of gluten per pill (for reference, a slice of bread labeled ‘gluten-free’ may contain up to 0.57 mg of gluten and still meet FDA criteria for being considered gluten-free).

Drug Information Resources

DailyMed (https://dailymed.nlm.nih.gov/dailymed/) is a reputable online resource for pharmacists to use as you are able to see the active and inactive ingredients in each geneic formulation of a drug. This may be a complicated resource for patients, so make sure to limit this resource to your own education.

Currently, there are several oral contraceptive options available that are gluten-free. To be 100% certain, it is best to consult either DailyMed or the package insert for the ingredient lists.

Patient Counseling

Ultimately, it is up to the patient to decide if they feel comfortable taking their particular oral contraceptive. If there is any uncertainty about a medication’s gluten-free status, contacting the manufacturer directly is the best way to clarify. Other birth control methods that don’t include gluten are non-oral options such as the Depo-Provera® shot, Nexplanon® implant, vaginal rings, condoms (depending on lubricant used), diaphragms, IUDs, transdermal patches and more.

As pharmacists, it is important to make note of patient allergies on their profiles as well as counsel patients on the inactive ingredients in their medications so that patients can feel more confident and at ease while taking their medications. You can apply your skills when caring for patients by keeping track if generic manufacturers change and informing patients if they are able to continue taking their medications.

References

1. United States, Congress, Food and Drug Administration. “Gluten in Drug Products and Associated Labeling Recommendations: Draft Guidance for Industry .” Gluten in Drug Products and Associated Labeling Recommendations: Draft Guidance for Industry, 2017, pp. 1–12.
2. Parrish, Carol. “Medications and Celiac Disease- Tips from a Pharmacist.” Celiac.org, Jan. 2007, celiac.org/main/wp-content/uploads/2009/11/Medications_and_Celiac_Disease.pdf.

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About the Author

Niamh O’Grady, PharmD Candidate, is a pharmacy student in the Class of 2021 at the University of California San Francisco School of Pharmacy.

Article reviewed by Breanna Failla, PharmD Candidate and Brooke Griffin PharmD, BCACP