Drug infusions can be exposed for prolonged periods to 'in-use' conditions where the temperature of an infusion in a holster-worn infusion pump may reach 37 degrees C. In this study, the stability of three cytotoxic drug infusions (carboplatin, 5-fluorouracil and mitozantrone) and one analgesic infusion (diamorphine HCl) was determined in Parker Micropump medication reservoirs under refrigerated storage and prolonged in-use conditions. The stability of the three cytotoxic drug infusions was unaffected by 14 days storage at either 4 or 37 degrees C. The diamorphine HCl infusion was stable over 14 days storage at 4 degrees C but under in-use conditions at 37 degrees C, drug degradation became significant (greater than 5%) if storage exceeded 7 days.