To determine volume loss when Schedule 8 (S8) liquid medicines are measured during routine dispensing and checking processes.Method:
A literature review and policy review of local, state and territory practices pertaining to S8 liquid medicines discrepancies was conducted, including measuring techniques, monitoring and reporting requirements. Hospital staff and manufacturers were surveyed to identify commonly used measuring techniques relevant to S8 liquid medicines. Subsequently, an experiment was conducted with 3 measuring techniques (bung, needle, cannula) to identify if measuring technique, S8 liquid viscosity, frequency of dispensing and duration of storage influence volume loss.Results:
Policy review did not uncover substantial guidelines to inform practice. Survey findings demonstrated a lack of uniformity with the 3 commonly used measuring techniques. These 3 techniques were investigated. A bung with an oral syringe resulted in the least amount of loss independent of the frequency of dispensing or viscosity of the liquid measured; less than 1% of the liquid remained in the syringe after a dose was removed. Average discrepancy associated with this technique was 3.4% when the volume recorded in the S8 register was compared to the actual volume measured at each dispensing.Conclusion:
Under laboratory conditions, volume loss through routine measurement and dosing of S8 liquid medicines was on average 3.4%. We recommend that a 4% discrepancy for S8 liquid medicines be included in institutional policies when utilising the bung and oral syringe technique.