Disclosed are apparatus and methods for producing and delivering vapour medicament. An exemplary apparatus disclosed comprises: a gas inlet for receiving a gas from a source of pressurized gas； a chamber for receiving a liquid medicament therein, the chamber being in communication with the gas inlet for permitting entrance and expansion of the gas in the chamber in the presence of the liquid medicament to produce the vapour medicament； and a vapour outlet in communication with the chamber for delivering the vapour medicament.
