The present invention provides a reservoir compartment adapter for use with a fluid delivery device. The adapter includes a first end adapted for coupling with a fluid delivery device, a second end adapted for coupling with a connector, and a structure between the first end and the second end including an interior space for receiving the reservoir, wherein an extended reservoir compartment for accommodating the reservoir is adapted to be formed when the first end is coupled to the fluid delivery device, and the reservoir is adapted to be secured in the extended reservoir compartment when the connector is coupled to the second end. The adapter allows a user of a delivery device accommodating reservoirs of a certain size to manage periods where increased medication dosage is needed without the burden of carrying a larger delivery device for accommodating reservoirs filled with the increased dosage.
