A friend of mine has ADHD and is also very gluten-sensitive. Recently, she has been suffering with one inexplicable malady after another. Finally, an explanation: the gluten in the generic medication she has been taking.
Here is an excerpt from the Celiac Disease & Gluten Sensitivity page at Verywell.com:
For both the consumer and the pharmacist, unless a medication is specifically labeled as gluten-free, calling the manufacturer is the only way to confirm the medication’s gluten-free status.
How Is Gluten Hidden In Medications?
In prescription and over-the-counter medicines, fillers (also called “inactive ingredients” or “excipients”) are added to the active drug. Fillers provide shape and bulk for tablets and capsules, aid in water absorption (helping the tablet to disintegrate), and serve other purposes as well. Fillers can be derived from any starch source, including corn, potatoes, tapioca and wheat.
Unfortunately, very few medications are labeled as gluten-free. Inactive ingredients may be listed on the box or the package insert, but it is difficult if not impossible (even for pharmacists) to tell if these are derived from gluten. [continued at the link above]