I have been taking 10 mg Singulair and 10 mg Cetirizine for five years for allergies, asthma, and Lyme. I just got two more kittens, and the medicines do not work anymore. I am miserable and desperate. I asked my doctor to give me 20 mg of Cetirizine and something else because I think my body is immune to 10 mg. Please advise on what better set of medication I should ask for. This is what I thought I should ask for - Cetirizine, Prednisone, Xyzal and Fluticasone propionate nasal spray.