Effect of placebo substitution during long-term betamethasone valerate aerosol treatment in asthmatic children.

Abstract

(1975). Archives of Disease in Childhood, 50, 387. Effect of placebo substitution during long-term betamethasone valerate aerosol treatment in asthmatic children. Ten children with severe asthma, who had been well controlled on maintenance betamethasone valerate aerosol for an average of 11 months, were given placebo aerosols without their knowledge. The period of placebo substitution was compared with one 28-day period of betamethasone valerate therapy beforehand, and two 28-day periods afterwards.Symptoms were increased during the placebo period, and patients did not return to their previous well-controlled state until the second month after reinstitution of therapy. Changes in the means of twice-daily peak expiratory flow readings (PEFR) followed the same pattern as changes in symptoms. The exacerbation of asthma which occurred during placebo treatment was accompanied by a widening in the diurnal variation between morning and evening PEFR. In comparison with the previous period, morning PEFR fell by a greater amount than evening PEFR. Standardized running tests suggested an increase in exercise-induced bronchoconstriction and in the Exercise Lability Index when the child was receiving only placebo treatment as compared with betamethasone valerate treatment.The trial provided further evidence of the efficacy of betamethasone valerate aerosol in the prophylactic therapy of severe childhood asthma. As 2 of these children were able to discontinue long-term therapy it is unlikely that this drug causes dependency.Recent studies have shown the effectiveness of betamethasone valerate aerosol in the prophylactic therapy of severe childhood asthma (Frears, Wilson, and Friedman, 1973;McAllen, Kochanowski, and Shaw, 1974). These findings are comparable with those shown in children using a different inhaled steroid with high topical activity, beclomethasone dipropionate (Dickson et al., 1973;Morrow Brown and Storey, 1973).Follow-up of children using betamethasone valerate aerosol for longer than a year (Frears and Friedman, 1974) has shown that the initial dramatic clinical improvement experienced by most patients continues over some time and is then maintained.Many parents claim that with this therapy their children have been in better health than at any time