Introduction

Pharmacology of Advair Diskus
Fluticasone Propionate (FP), a component of Advair Diskus, is a corticosteroid primarily used in the treatment of asthma, allergic rhinitis (AR), or chronic obstructive pulmonary disease (COPD).1,2,3,4 In patients with allergic rhinits, is it most often used intranasally, falling under the class of “intranasal corticosteroids”, or INS.3 However, in the case of asthma, the drug is classified as an “inhaled corticosteroid” or ICS.5 Typically short-acting β2 adrenoreceptor agonists are used to rapidly treat the symptoms of asthma, but corticosteroids like FP are utilized when long-term contol is required.6 FP has been obsered to have synergistic effects when used in co-therapy with these short-acting β2 adrenoreceptor agonists, yielding a greater improvement in lung treatment and symptom control than when either of the two drugs is adminstered alone.6
The corticosteroid drug class has been around …show more content…
Additionally, it is imperative that these therapies possess a limited ability to enter circulation from the lung and/or nasal tissue. Due to these requirements, the most extensively studied pharmacokinetic parameters for INS and ICS are lipophilicity and systemic availability.3
Fig. 5, by Kaliner, is an illustration of the metabolic fate of FP when taken as an ICS. After inhalation only 10-40% of the drug is deposited in the lung where it an be absorbed and potentially iteract with GR to produce the desired therapeutic effect. The remainder of the drug is swallowed, where it is eventually abosorbed from the gut and passes through the liver, after which it may enter systemic circulation and potentially produce adverse