Influence of inspiratory flow rate upon the effect of a Turbuhaler.

The effect of a new breath actuated dry powder inhaler, the Turbuhaler, was found to be reduced at inhalations slower than 28 1/minute. This flow rate could be generated by virtually all children aged greater than or equal to 6 years, by 42 of 57 children less than 6 years (74%), and by six of 15 preschool children with acute wheeze (40%).