Dry powder inhalers

A dry powder inhaler comprises a mouthpiece 12 through which in use a user can inhale a powdered medicament. A mouthpiece obstruction or cover 6,8 is arranged to prevent a user properly inhaling through the mouthpiece. A plurality of medicament doses are provided in individually sealed compartments 24. The inhaler has means 48,50 for breaching the seal 25 of one of said compartments 24 to establish a pathway between that compartment and the mouthpiece 12, wherein the mouthpiece obstruction or cover 6, 8 is mechanically coupled to the seal breaching means 48, 50 so as to operate the latter when the mouthpiece obstruction or cover is opened. Also disclosed is a dry powder inhaler comprising a plurality of dose compartments 24 covered by sealing member 25. The inhaler further comprises one or more piercers 52, 54. The piercers 52, 54 are so shaped and arranged that upon penetration of the sealing member they form a hollow tube therewith for communicating with the interior of the compartment.