If you’re down with the flu or a cold, it’s best to follow the gluten-free diet. This also includes gluten-free cough, cold and flu medications. Fortunately, you can find a wide variety of options available in pharmacies and several online stores. For instance, Avid Cold and Sinus is gluten-free cough medicine. Similarly, Afrin, Alka-Seltzer Plus, Delsym, Mucinex, and Sudafed are a few popular no gluten medicines that treat cold and cough effectively.