MODEL RELEASED. Asthma inhaler. Man using a pressurized aerosol Ventolin inhaler to control an attack of asthma. The Ventolin inhaler uses a drug called salbutamol which dilates the bronchial muscles, allowing air to pass to the lungs. In bronchial asthma an allergic reaction to particles in the air causes a spasm of the muscles in the bronchial tubes which narrows the airways. These spasms are associated with swelling of the lining surfaces and an increased production of secretions.