RESUMO
OBJECTIVES: Single-size vials of drugs may be a source of waste and increase in treatment costs. Bortezomib, indicated for multiple myeloma (MM) treatment, is available in 3.5-mg vials, a quantity higher than the average dose commonly prescribed. This analysis aimed to demonstrate, through real-world data, which would be the optimal vial presentation for bortezomib in Brazil and quantify the reduction in medication waste related to this option. METHODS: From November 2007 to October 2009 all patients with MM treated with bortezomib were identified via the Evidências database. Analysis of prescribed, dispensed, and wasted doses, their costs and projections of the ideal vial size were performed. RESULTS: Thirty-five patients (mean body surface area of 1.73 m(2)) received 509 infusions in 131 cycles of treatment (average of 3.77 cycles per patient). The average dose prescribed was 2.1 mg per infusion (95% confidence interval [CI] 1.97-2.26) with average waste of 39.5% of the vial content (95% CI 35.35-43.76). The mean waste per patient per day was 1.38 mg (95% CI 1.24-1.52). If a 3-mg vial were available, the average drug waste per patient per day would be 0.88 mg (95% CI 0.74-1.03) or 36.2% less. With a 2.5-mg vial the waste would be 1.05 mg (95% CI 0.81-1.29) or 23.9% less. If two presentations were available (2.5 mg and 0.5 mg), the waste would be 0.52 mg (95% CI 0.4-0.63) or 62.5% less. Considering the price of the different vials to be proportional to the original 3.5-mg vial, the cost would be also reduced by the same rates described above. CONCLUSIONS: A simple adjustment in vial size may reduce the waste of bortezomib by 36% to 62% and can also reduce the cost of treatment.