Comparing inhaled glucocorticosteroids

Inhaled glucocorticosteroids (GCSs) have a much lower potential for systemi c effects than oral steroids. Nevertheless, the potential systemic effects of inhaled therapy are still an issue of concern, especially to pediatricia ns. Therefore, great efforts have been made to develop new GCSs with even l ess systemic activity for a given clinical effect. Claims are often made th at some inhaled GCSs have a higher potency and/or a lower potential for sys temic effects than others, but there is still much debate about the clinica l importance of this and about how such possible differences should be asse ssed. Both the desired and the unwanted effects of inhaled GCS therapy can be mea sured in many different ways, but the results of different measurements are not always in agreement. This makes the whole issue of inhaled steroid the rapy complex and confusing for many clinicians. Because the prescriber of a n inhaled steroid is faced with an increasingly wide range of drugs and del ivery devices, it would be helpful if it were possible to calculate benefit :risk ratios for all available combinations of drug and inhaler. This paper summarizes some of the most important factors to be considered w hen assessing the efficacy and safety of inhaled GCS therapy and comparing the properties of the various drug-inhaler combinations. It also highlights some pitfalls and problems associated with comparisons between inhaled GCS s in an attempt to provide the reader with a better basis for understanding some of the apparent discrepancies in results between different studies.