Inhaled lactose-free sodium cromoglycate powder in the treatment of recurrent asthma.

Sodium cromoglycate is widely used in many countries as a first-line drug in the prevention of bronchial asthma, but in others, particularly the United States, there are doubts about its role. It has been suggested that the lactose, which was used as a carrier substance in the earlier preparation, might have contributed to the apparent efficacy of the drug. In view of this a double-blind controlled trial comparing inhaled lactose-free sodium cromoglycate powder (C) with placebo (P) has been undertaken in patients with chronic asthma not adequately controlled by bronchodilators. Thirty adult patients (15 C, 15 P) with demonstrable reversibility of their airflow obstruction of at least 20% and who were not taking corticosteroids or sodium cromoglycate were admitted to the study. The C patients had, on average, more severe asthma in the 4-week pretrial assessment period and were taking more bronchodilators. After 12 weeks on trial therapy the results for the C group were significantly better than for the P group in terms of changes in symptom scores, the amount of inhaled bronchodilator used and morning and evening peak flow rates. There was already evidence of greater improvement in the C group by 4 weeks. These results indicate that in this group of atopic patients with frequent asthma symptoms despite bronchodilator therapy, inhaled lactose-free sodium cromoglycate powder provided improved control of asthma symptoms.