Inhaled and nasal corticosteroids: factors affecting the risks of systemic adverse effects

There has been increasing concern in the medical literature about the safety of inhaled and nasal corticosteroids, since many patients, both adults and children, are increasingly prescribed these drugs for the long-term prophylactic treatment of asthma and rhinitis. It is well recognised that systemic absorption occurs following inhaled and nasal administration of corticosteroids, but the dose at which clinically relevant side effects occurs is controversial. The controversy stems from the fact that the degree of systemic absorption depends not only upon the prescribed dose, but also upon the mode of delivery and the severity of the underlying disease. From a regulatory view, it is essential that the Product Information (Summary of Product Characteristics and Patient Information Leaflet) reflects the available evidence to enable a doctor to make an informed decision when prescribing these medicines. This article assesses the potential for inhaled and nasal corticosteroids to cause systemic adverse effects by analysing the published literature and spontaneously reported suspected adverse drug reactions reported to the Committee on Safety of Medicines and Medicines Control Agency. Five main areas of concern were reviewed: hypothalamic-pituitary-adrenal axis suppression, osteoporosis or changes in bone mineral density, growth retardation in children, cataracts, and glaucoma. Conclusions regarding these side effects at licensed doses of inhaled and nasal corticosteroids are reached and the clinical relevance is discussed, particularly following long-term therapy. The recommendations of the Committee on Safety of Medicines and Medicines Control Agency are included.