Aim: The effects of cessation of therapy with inhaled steroids on symptoms, lung function, and airway responsiveness in stable bronchial asthma should be examined.
Patients and methods: During a 4-week run-in period 24 patients inhaled beclomethasone dipropionate (BDP) 2000 micrograms/d and salbutamol 800 micrograms/d. This was followed by a 6-week treatment period during which the patients obtained either placebo plus 800 micrograms salbutamol or 2000 micrograms BDP plus 800 micrograms salbutamol in a randomized double-blind design. Symptoms, lung function, and airway responsiveness to histamine were measured before and after the run-in period and at the end of each week during the treatment period.
Results: Airway responsiveness was assessed as the concentration of inhaled histamine which caused a 20% fall in FEV1 compared to baseline (PC20). During the run-in period, 21 of the 24 patients showed an increase of PC20 (p = 0.0005). In the placebo group, 5 patients had to cease the protocol after 1 to 4 weeks of the treatment period because of intolerable symptoms and severe worsening of lung function; PC20 on entry was significantly smaller in these patients compared to those who completed the protocol (p = 0.01). After 6 weeks, FEV1 had decreased by 8.5% (p = 0.005) and PC20 by 1.71 doubling concentrations (p = 0.0003). In the BDP group, all patients completed the study and PC20 after the treatment period was significantly higher (p = 0.04) in the BDP than in the placebo group.
Conclusion: Our data suggest that patients on long-term inhaled steroid therapy with a high degree of bronchial hyperresponsiveness are more likely to show early deterioration of their clinical state after cessation of inhaled steroids.