A dual reservoir fluid dispensing apparatus for use in controllably dispensing fluid medicaments, such as antibiotics, analgesics and like medicinal agents from either or both of the device reservoirs. The fluid dispensing apparatus includes novel fill means for selectively filling each of the reservoirs with the same or different medicaments that are to be dispensed to the patient. Stored energy sources are provided in the form of a pair of constant force spring members of novel design that provide the force necessary to continuously and substantially uniformly expel fluid from the reservoirs. The apparatus also includes novel adjustable flow rate assemblies that are disposed intermediate the outlet port of the fluid reservoirs and the outlet port of the device for precisely controlling the rate of fluid flow from the outlet port toward the patient.