A dry powder medicament inhaler (100) for metering an inhalation of dry powdered medicament is provided. The inhaler (100) comprises at least one inlet (101) and at least one outlet (102) wherein a communication between said at least one inlet (101) and said at least one outlet (102) at least comprises a mixing and deaggregation chamber (106) and at least two dosage communications (107) between the at least one inlet (101) and the chamber (106). The inhaler (100) further comprises a dosage mechanism (104 108) for arranging at least one dose of a medicament between the inlet (101) and the chamber (106) such that said at least one dose may be delivered upon inhalation at said outlet (102) through said communications (107). The inhaler (100) may comprise a locking mechanism (200) wherein on moving the dosage mechanism (104 108) from a dose collecting position to a dose administering position the locking mechanism (200) is moved from an unlocked to a locked position preventing the metering of any further doses prior to resetting of the locking mechanism. Instead of a locking mechanism (200) the inhaler may comprise a dosage indicator (300) or a counterweight mechanism (420). The inhaler (100) may also comprise combinations of a locking mechanism (200) a dosage indicator (300) and a counterweight mechanism (420).
