Is here a difference between singulair (montelukast) and advair?

Yes: Singulair is a tablet containing montelukast, a leukotriene modifier, that helps to reduce asthma inflammation. Advair is an inhaler that contains fluticasone (a steroid) and salmeterol (a beta-agonist). Advair decreases inflammation with the inhaled steroid and helps open the airways with the bronchodilator/ beta-agonist. Advair is for more severe asthma than singulair.

Yes: Advair is an inhaled medication containing an inhaled steroid and a long acting beta agonist. This is used for asthma and COPD Singulair is a pill and is a leukotriene antagonist developed for use in asthma and allergies. Unfortunately, in my experience, Many patients are on singulair and I really have never seen a benefit.