Corticosteroids in treatment of chronic asthma.

Chronic or continuous bronchial asthma is a disabling and potentially dangerous disorder, for which the only effective treatment in the majority of cases is the administration of corticosteroids. There was at first some reluctance to use these agents on a long-term basis, mainly because of a discouraging report from the Medical Research Council (1956), but in the past nine years many well-documented studies have testified to the value of this form of treatment (Phear, Ball, and Page, 1960; Bruce Pearson, Baylis, and Smellie, 1961; Livingstone and Davies, 1961; Rees and Williams, 1962). There are indeed few respiratory physicians who do not now believe that it is indispensable to the management of severe chronic asthma. In the Respiratory Diseases Unit of the Northern General Hospital, Edinburgh, corticosteroids have been used in the treatment of chronic asthma since 1953. Until 1958 we adopted the then orthodox policy of selecting patients for long-term treatment on purely clinical criteria. Patients with severe asthma which did not respond adequately to bronchodilator drugs were first given a seven-day course of corticosteroid. If the asthma was of the chronic or continuous type there was inevitably a recurrence of symptoms a few days or a few weeks after treatment was stopped. Another course of corticosteroid was then given, and the cycle of improvement and deterioration was usually repeated. After a time, often as a result of pressure from the patient or from the general practitioner, and seldom as a deliberate decision, a daily maintenance dose of corticosteroid was sanctioned by the consultant, and this form of long-term treatment, once started, could seldom be stopped, even for a day. This was clearly an unsatisfactory way to use a potentially dangerous drug, and in 1958 one of us (I. W. B. G.), working in collaboration with Dr. A. R. Somner, decided to experiment with methods of administering corticosteroids intermittently. It had been observed that in most cases of chronic asthma the improvement produced by a short course of corticosteroid persisted for a few days after treatment was stopped, and there appeared to be fairly good grounds for assuming that, in some patients at least, symptoms could be controlled by the administration of corticosteroids for two or three consecutive days every week, or for a longer period every fortnight or every month. It seemed possible that if a regimen of this type could be used the various metabolic disturbances caused by the short courses of corticosteroid would subside or perhaps even be entirely reversed during the periods between treatment. Some support for this hypothesis has since been obtained from the work of Harter, Reddy, and Thorn (1963), who showed that the metabolic effects of a single dose of prednisone given every 48 hours were substantially corrected during the second period of 24 hours after each dose was given. The results of our preliminary experience with intermittent corticosteroid therapy in chronic asthma were reported six years ago (Somner, Rogan, and Grant, 1960). Groups of severe but otherwise unselected chronic asthmatics were treated with 20 mg. of