Drug dispenser for use with intravenous feeding pump

Abstract

This invention relates to a drug dispensing capsule in which the drug may be first mixed with a predetermined quantity of parenteral fluid (the solution to be administered to the patient). It is adapted to be used at the discharge end of an intravenous feeding pump and will automatically switch over to the parenteral fluid as soon as the drug dosage has been dispensed. The device comprises a cylindrical chamber somewhat of the nature of an enlarged hypodermic syringe. It has an inlet at one end and an outlet at the other. A piston-like fluid separator is slidably mounted on the interior of said cylindrical chamber. The drug mixture to be administered is placed in the chamber between the piston and the discharge end of the chamber. The capsule is placed in the pumping system at the discharge end of the pump, the outlet from the device being connected to the tube to the needle inserted in the blood vessel of a patient. When the pump is operated, it pushes the piston axially in the cylinder thereby forcing the drug dosage out of the outlet end of the chamber and into the patient. When the piston reaches the end of the cylinder, the seal between the piston and the wall of the chamber is automatically broken, as by means of ridges projecting inwardly from the wall of the chamber, or by cavities formed in the wall thereof. Means is provided for exhausting air from the chamber, both when the parenteral fluid is introduced into the chamber and when a capsule with its premeasured dosage is placed in the system.