CP-034 Economic impact of the introduction of a compounded 50 mg/ml mercaptopurine suspension in a teaching hospital

Background Mercaptopurine is indicated for the treatment of acute lymphoblastic leukaemia (ALL). In our country, there is no commercial presentation that allows proper dosage in paediatric patients. However, in March 2012, an expensive 20 mg/mL mercaptopurine suspension (100 mL) that may be purchased as a foreign drug was commercialised. In order to meet the needs of these patients using a more cost effective alternative, the pharmacy department developed a mercaptopurine compounded drug. Purpose To assess the economic impact of the development of a 50 mg/mL mercaptopurine suspension (12 mL) compared with the use of a commercial syrup. Material and methods Mercaptopurine suspension is compounded by adding simple syrup, cherry syrup and sterile water for irrigation to 50 mg of mercaptopurine triturated tablets. It is prepared in a biological safety cabinet, packed in amber glass bottles and its shelf life is 28 days. This was a retrospective study from March 2012 to September 2015. Collected data, from Farmatools and Farmis software, were: number of ALL patients treated with the suspension, number of suspensions dispensed, number of mercaptopurine tablets used and its cost, and treatment phase of the ALL-SEHOP-PETHEMA protocol when the dispensation was done. Mercaptopurine suspension appraisal was done according to the valuation rules of the Regional Health Management. The Ministry of Health website was consulted for the commercial suspension price. Total savings by the development of a compounded medicine instead of buying the commercial presentation was established by comparing the direct costs between both alternatives. Results During the study period, 40 mercaptopurine suspensions were prepared to treat 3 patients (according to the ALL-SEHOP-PETHEMA protocol, 2 suspensions were dispensed for the consolidation phase of the treatment and 38 for the maintenance phase). Each one cost 28.1€ (16.6€ mercaptopurine suspension, 0.3€ storage, 11.2€ professional fees); total expenditure was 1124€. Each commercial suspension costs 269.36€ and its shelf life is 56 days; total expenditure would have been 5387.2€. Cost savings achieved by developing the mercaptopurine suspension instead of buying the commercial presentation was 4263.2€. Conclusion The compounded 50 mg/mL mercaptopurine suspension can meet the therapeutic needs of ALL paediatric patients and save costs. It would be useful to assess the addition of a preservative to the compounded suspension to increase its shelf life and save on costs. No conflict of interest.