A monodose inhaler for powdered medicaments consists of a hollow substantially pipe-shaped body that has a first portion (H), for housing a capsule or cartridge of powdered medicament, defined by a wall (W) in which there are formed slots (S) as air intakes to an inner region where the powder drops, and a second portion (M) connected to the first portion (H) for delivering the medicament by means of a primary stream (F) that carries the powder from the drop region along a delivery duct (D) whose end is suitable to be placed in the patients mouth, and it further includes a secondary duct (D) located under the delivery duct (D) and provided with its own air intake (S) for delivering a powderless secondary stream (F). This stream (F) supports and directs the primary stream (F) so that it can climb over the patients tongue, thus preventing the excessive deposition of the medicament in the oropharingeal cavity and obtaining a greater effectiveness of the treatment thanks to the larger amount of medicament that reaches the lungs. Other advantages of this inhaler are the better separation of the drug from the excipient due to the secondary stream (F) that hits and directs the primary stream (F), and its low cost thanks to the fact that it can be manufactured in plastic by injection molding with a monolithic structure and therefore can be used as a disposable inhaler.
