Singulair is a leukotriene inhibitor. Leukotrienes are chemicals your body releases when you breathe in an allergen (such as pollen). In turn, it also eases inflammations in the lungs (or opens them up). So yes, it's normal to feel like you can draw more in while on Singulair. When I first started on it, it felt like I was sucking on a cold wind pipe. That feeling went away after a while. The way it works can also help your sinus passages, which allow more "smells".
Moderator-Allergies/Asthma and Alzheimer's, Co-moderator-UC
Diagnosed Left sided UC in '92 - meds: 6mp, Colazal, Remicade and Bentyl*Unable to tolerate ALL mesalamines*, in '11 diagnosed with IBS, Diverticulosis, Fibromylagia..I also have Sacroiilitis, Scoliosis, Raynauds, OA, PA, Rosacea, Psoriasis, Dry Eye and allergies controlled by Zyrtec and Singular