Disclosed is an inhaler (10) for an inhalation formulation (14). The inhaler (10) is comprised of a canister (12) containing a pharmaceutical composition (14) under pressure, a metering valve (18), and an actuator (22). The metering valve (18) measures a metered dose of the composition (14) from the canister (12) for administration to a patient in need thereof. The actuator (22) actuates discharge of the metered dose to the patient. The actuator (22) includes a discharge orifice (28) having a diameter in the range 0.2 to 0.4 mm. The pharmaceutical composition (14) comprises an anticholinergic agent and a pharmaceutically acceptable propellant. The metered dose contains 2.5 micrograms to 18 micrograms of the anticholinergic agent.
