Steroid safety: the endocrinologist's view

Asthma guidelines recommend the use of inhaled glucocorticoids (GCS). However, high doses increase the risk of systemic effects including suppression of the hypothalamic-pituitary-adrenal (HPA) axis by negative feedback, reduction of bone mass, inhibition of growth in children and skin thinning. Plasma concentration depends on the dose delivered from the inhaler, the distribution of delivery (ratio of lung to gut), and the degree of first-pass metabolism. Improving lung delivery increases lung absorption and reduces gut absorption and, depending on the extent of first-pass metabolism, may have significant effects on the systemic drug load. Qvar (3M Pharmaceuticals' hydrofluoroalkane beclomethasone dipropionate (HFA-BDP)), which produces an extra fine aerosol, improves lung delivery without producing clinically significant HPA suppression within the recommended dose range. Within this range Qvar produces no more HPA suppression than an equal dose of CFC-BDP and, in addition, lower doses of Qvar are effective in asthma control.