A dry powder medicament inhaler for metering an inhalation of dry powdered medicament may include at least one inlet and at least one outlet, wherein a communication between said inlet and outlet at least includes a mixing and deaggregation chamber and at least two dosage communications between the inlet and the chamber. The inhaler may also include a dosage mechanism for arranging at least one dose of a medicament between the inlet and the chamber, such that said at least one dose may be delivered upon inhalation at said outlet through said communications. The inhaler may further include a locking mechanism, wherein on moving the dosage mechanism from a dose collecting position to a dose administering position the locking mechanism may be 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, the inhaler may include a dosage indicator or a counterweight mechanism. The inhaler may also include combinations of a locking mechanism, a dosage indicator, and a counterweight mechanism.
