Does ketotifen have a steroid-sparing effect in childhood asthma?

In view of the possible systemic side-effects of inhaled corticosteroids (ICS), a study was performed to determine whether ketotifen (versus placebo) can replace or allow a reduction in the dose of ICS required for the maintenance treatment of childhood asthma. Sixty six children (aged 6-13 yrs) with asthma (confirmed by methacholine challenge), who were maintained on ICS, at a dose of < or = 1 mg.day-1, were selected, and 52 subjects completed the trial. Children on long-term oral steroids or cromoglycate were excluded. After a 4 week baseline period, the children were randomized to receive ketotifen, 2 mg.day-1, or placebo for 32 Weeks. Between weeks 13-20 of the study, the daily dose of steroid was tapered by 25% every second week to the minimum dose tolerated by the patients. For the remainder of the study (Weeks 21-32) the patients continued on this dose (if tolerated). Beta 2-agonists were allowed, as necessary, for symptom relief. During the baseline period, the mean daily ICS dosage was 432 micrograms in the ketotifen group versus 408 micrograms in the placebo group (NS). Among the-patients who completed the study, the average ICS dosage during the final phase of the study (Weeks 21-32) was only 18% of baseline in the ketotifen group versus 35% in the placebo group (NS). Lung function, diurnal variability in peak flow rates and methacholine sensitivity (provocative concentration producing a 20% fall in forced expiratory volume in one second (PC20)) remained unchanged in both groups throughout the study. During the last 12 weeks of the study, the ketotifen-treated patients were symptomatically better controlled. In the present study, ketotifen did not have a greater steroid-sparing effect than placebo.