Inhalation devices that receive a blister pack comprising a number of blisters each of which contain a pre-metered and individually packaged dose of the drug to be delivered are known. Used blisters can be simply wound around a take-up spool within the device. However, such devices are large and require means to rotate the spool to wind up the used blisters. The leading end of the strip must also be pre-attached to the spool so that the strip starts to wind around the spool as the spool is rotated. Accordingly, a dry powder inhaler having a chamber divided into first and second blister compartments for storing unused and used portions of a blister strip is provided. A moveable dividing wall separates the first and second blister compartments. Three arcuate supporting surfaces are disposed inside the chamber and support the used or unused blister strip during successive actuations of the inhaler. A blister strip guide rib controls the direction of the used blister strip as it enters the second blister compartment.
