Six year old child using a pressurized aerosol Brycanyl inhaler to control recurrent attacks of asthma. The Brycanyl inhaler uses a drug called terbutaline, which dilates the bronchial muscles, allowing air to pass to the lungs. In bronchial asthma the narrowing of the airways is produced by spasm of the muscles in the bronchial tubes. These spasms are associated with swelling of the lining surfaces & an increased production of secretions.