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.
The aim of this article is to bring less well recognised adverse effects of inhaled corticosteroids to the attention of prescribers. Whilst inhaled steroids have a more favourable side effect profile than systemic steroids, they are not free from adverse effects. The dose of inhaled steroids used should be carefully monitored, and kept at the lowest dose necessary to maintain adequate control of the patient’s disease process. Be particularly aware of the cumulative effect of co-prescribing various dose forms of corticosteroids (inhaled, intranasal, oral and topical preparations).
Given the published evidence, ICSs should be continued throughout pregnancy at low to moderate doses sufficient to control asthma symptoms and prevent exacerbations. However, caution must be taken with doses greater than 1000 µg/d (chlorofluorocarbon beclomethasone equivalent), although whether such doses cause adverse effects is currently still questionable. Patient education on proper ICS administration and adherence, including during the first trimester, must be ongoing. Well controlled asthma will reduce the need for higher ICS doses and possible exposure to systemic corticosteroids, and might decrease the risk of adverse pregnancy or perinatal outcomes.