This was a retrospective observational study of COPD patients in the United States treated with LABA/LAMA or LABA/ICS combination. Insurance claims from January 1, 2004, through December 31, 2014, were used as the data source. Patients were required to have greater than one prescription filled for the combination medications, and they were followed from 30 days after drug initiation. Individuals were censored if they discontinued a study medication, initiated medication from the opposite cohort (LAMA or ICS), lost enrollment eligibility, or at the study period end. Exacerbation rates were compared using Poisson regression.
Certain drugs such as troleandomycin (TAO), erythromycin ( Ery-Tab , EryPed 200), and clarithromycin ( Biaxin ) and ketoconazole ( Nizoral ) can reduce the ability of the liver to metabolize (breakdown) corticosteroids and this may lead to an increase in the levels and side effects of corticosteroids in the body. On the other hand, phenobarbital, ephedrine , phenytoin ( Dilantin ), and rifampin ( Rifadin , Rimactane ) may reduce the blood levels of corticosteroids by increasing the breakdown of corticosteroids by the liver. This may necessitate an increase of corticosteroid dose when they are used in combination with these drugs.