in sleep onset latency between placebo (median 11, range 2-49 mins) and salmeterol 50 .sg twice daily (13, 5-53 mins). In fact the major determinant of the observed decrease in wakefulness and drowsiness between salmeterol 50 ig twice daily and placebo was a reduction in intervening wakefulness throughout the night. Mr Sarin and colleagues suggest that the effect of salmeterol 100 Fg twice daily on sleep quality was little different from that of salmeterol 50 [sg twice daily, but this suggestion conflicts with the study data. There was no significant difference in any objective sleep variable between the groups given placebo and salmeterol 100 .tg twice daily, and the observed increase in time spent in stage 4 sleep by those given salmeterol 50 [tg as compared with salmeterol 100 [g was significant (p