Fluticasone-salmeterol (brand name, Advair Diskus; GSK) is an
inhalation maintenance treatment for breathing difficulties caused by
COPD, such as wheezing, shortness of breath, coughing, and chest
tightness. It is a combination of an inhaled corticosteroid
(fluticasone) with a long-acting bronchodilator (salmeterol).
Fluticasone is a corticosteroid that works by reducing airway swelling.
Salmeterol is a long-acting beta-agonist (LABA) bronchodilator that
works by relaxing and opening the airways to the lungs, making breathing
easier.β-agonist Powder
The anti-inflammatory activity of fluticasone is what works upon disease processes in COPD, whose inflammatory agents include neutrophils, CD8+ T cells, and macrophages. The effects of corticosteroids in the treatment of COPD, however, are less well-defined than they are in treating asthma.
As a selective LABA, salmeterol’s effects are due to the stimulation of an enzyme, called adenyl cyclase, in lung muscle cells (bronchial smooth muscle). This enzyme helps convert adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP). When the levels of cAMP increase, the muscle cells relax.
Beta2-receptors are predominant in lung muscle cells, but they are also present in the heart, which means salmeterol may have cardiac effects like an irregular heartbeat.The efficacy of two different dosages of fluticasone-salmeterol oral inhalation — Advair Diskus 250 mcg fluticasone propionate/50 mcg salmeterol, and 500/50 mcg — was assessed in six studies in COPD patients age 40 or older. Significantly greater improvements in lung function, as defined by pre- and post-dose FEV1, were seen in patients treated with either dose of Advair, than in those treated with either fluticasone, salmeterol or placebo in two of three trials that focused on lung health; the third such study showed significant improvement with Advair Diskus 500/50 (the only dose tested in this yearlong trial) compared to either medication alone or placebo.
Two separate studies that focused on exacerbations in COPD patients tested Advair Diskus 250/50 against salmeterol 50 mcg, and found significantly lower annual rate of moderate or severe COPD flares in those given the combination oral inhalation treatment. Likewise, in one- and three-year studies of this inhalation therapy, fewer COPD flares were also reported in patients treated with either the 250/50 or 500/50 mcg doses than in those given comparator medicines or placebo. No significant differences were seen between the two dose levels.
A three-year study of Advair Diskus 500/50 mcg that focused on all-cause mortality did not find significant improvements in survival among those treated with this fluticasone-salmeterol combination, although better pulmonary function was reported in the treatment group compared to patients given salmeterol (50 mcg) or fluticasone propionate (500 mcg) as monotherapy, or placebo.
