A one-year double-blind clinical study of the efficacy and tolerability of picumast dihydrochloride versus ketotifen in patients with bronchial asthma.

The efficacy and tolerability of picumast dihydrochloride (3,4-dimethyl-7-[4-(4-chlorobenzyl)piperazine-1-yl]propoxycoumarin dihydrochloride) (2 mg twice daily orally) in comparison with ketotifen (1 mg twice daily orally) was investigated in 400 patients with bronchial asthma (picumast dihydrochloride n = 202, ketotifen n = 198) in a double-blind, controlled, parallel group study. Assessment of therapeutic and preventative efficacy was by means of symptom scores, quantitative measurements (accumulatory threshold dose) of the bronchial hyperreactivity by means of inhalatory acetylcholine provocation, measurements of peak expiratory flow, vital capacity (VC) and 1-s capacity (FEV1) as well as global assessment of efficacy by the doctor and patient. Tolerability was assessed by recording side effects and global assessment of tolerance on a rank scale at the end of the treatment as well as by means of clinico-chemical parameters. Picumast dihydrochloride and to a lesser extent ketotifen both led to a clinically relevant and statistically significant increase in the inhalatory provocation dose (PD50) for acetylcholine. There was a moderate improvement in the symptom scores and a rise in peak flow values in both treatment groups. The mean total score of asthmatic symptoms of both drugs showed a clear but quantitatively low improvement after 12 months' treatment. The differences in efficacy between picumast dihydrochloride and ketotifen were not statistically significant. During the course of the study, adverse reactions were recorded on 117 occasions (picumast dihydrochloride n = 41, ketotifen n = 76).(ABSTRACT TRUNCATED AT 250 WORDS)