A dispensing device for dispensing first and second medicaments to a patient that is made up of first and second stand-alone, interconnectable assemblies. The first of these assemblies comprises a fluid reservoir assembly that houses a fluid reservoir defining component while the second assembly comprises a fluid delivery and control assembly that includes an adding assembly for controllably dispensing the second medicament to the patient, a novel flow control means that functions to control the flow of medicinal fluid from the fluid reservoir of the first assembly toward the patient via a plurality of fluid flow control passageways. Because the stand-alone fluid delivery and control assembly is initially totally separate from the fluid reservoir assembly of the apparatus, the fluid flow passageways of the fluid delivery and control assembly can be effectively sterilized using conventional gamma ray sterilization techniques without adversely affecting the medicament contained within the fluid reservoir of the apparatus.