Evaluation of a spring-loaded syringe driver for the subcutaneous administration of narcotics

A simple spring-loaded syringe driver was tested for the subcutaneous administration of narcotic analgesics and antiemetics. With concentrations of 2 to 10 mg/mL of hydromorphone and 10 to 50 mg/mL of morphine, the infusion rate during preclinical testing was 1.01 ± 0.1mL/hr (range 0.70-1.2 mL/hr). The rate of infusion was not modified by the concentration of narcotic in solution. Clinical trials were performed with morphine in 17 patients, and with hydromorphone in 11 patients. The duration of the infusion was 21 ± 11 days. The most frequent reason for discontinuation was death (22 cases). The average duration of the site of infusion was 6.3 ± 4 days. When used subcutaneously, the rate of infusion of the device was 1 ± 0.15 mL/hr (range 0.70-1.30 mL/hr). Patients and nurses were satisfied with the simplicity and safety of the device. Cost analysis shows that this device is significantly less expensive than currently available portable infusion devices. We conclude that the Medifuse Pump is an inexpensive, safe and effective device for the subcutaneous infusion of narcotics and antiemetics.