Fluidising powdered medicament for inhalation comprises drawing air through an inhalation tube (1) closed by a chamber contg. the medicament and with air passage holes causing the air to fluidise and entrain the powder. Air is admitted to the tube downstream (6) of the chamber. Also claimed is a powdered medicament inhaler comprising an inhaler tube, chamber receiving means to receive a capsule or other chamber to close the tube and an air inlet downstream of the receiving means.