It is not just the fillers in generics we need to be concerned about. Supplements are another culprit in adverse reactions, even if you keep buying the same brand, because they are unregulated, their composition can change from time to time.

A different dosage of the same drug, name brand or generic, can contain a different filler or dye - for example, the medication in an extended release capsule versus a tablet, or a pink pill and a white one, or the flavoring in a liquid suspension, or the carrier in an ointment or gel. It is a constant mystery for those with sensitivities and allergies.
Sue