A breath actuated nebulizer for administration of an inhaled medication to a patient is provided with a generally cylindrical body in a horizontal orientation to the patient. Within the body is a Venturi configured to nebulizer a liquid medication in a reservoir. Within the body is a shaft integrated with a baffle and diaphragm that slides horizontally in response to the breathing of a patient. During inhalation by the patient, the diaphragm flexes shifting the baffle over the Venturi, allowing nebulization to occur. When the patient exhales, the diaphragm flexes to a default position in which the baffle is distal to the Venturi, thereby stopping the nebulization. The diaphragm is biased to rest in this default position until the patient inhales again.