A pump-type dispenser for dispensing predetermined doses of medicament in droplets or in spray form to the nasal area incorporates a rigid vial for medicament, an expandable pouch located within the rigid vial, a nasal screen, a one-way actuation mechanism, a one-way valve mechanism in the nozzle area and a spring element, both the valve mechanism and the spring element being formed as integral portions of the pump body. The nasal screen aligns the dispenser nozzle with the nasal passage and also allows the user to discreetly hide the nasal area from public view. The one-way valve mechanism in the nozzle area ensures a one-way movement of medicament from the dispenser, thereby preserving substantially perfect sterility of the medicament in the dispenser regardless of the environment surrounding the dispenser, without requiring the use of preservatives. The one-way actuation mechanism enables the user to load and dispense a uniform quantity of medicament with a uniform actuation force and speed via a single continuous motion of the actuation mechanism upon application of a very small force on the actuation trigger mechanism by the user. By preventing the pump mechanism from being left in a loaded state for a prolonged period of time, the one-way actuation mechanism prevents the spring element from experiencing the "fatigue" phenomenon. The rigid vial/expandable-pouch combination facilitates improved long term use, as well as uniformity of dosage independent of the pump orientation.