The present invention provides an inhaler comprising a housing which contains a blister strip having a plurality of blisters which contain powdered medicament for inhalation, a mouthpiece mounted to the housing through which the medicament is inhaled by a user, an indexing and opening mechanism for indexing the blister strip and for opening the blisters which is operated by an actuator, wherein the blister strip is indexed by forward motion of the actuator from a first position to a second position, such as by opening a cover, and is also indexed in the same direction by reverse motion of the actuator from the second positon to the first position, such as by closing the cover.
