Wastage of injectable anticancer drugs in a public hospital chemotherapy compounding unit: A prospective descriptive study

IntroductionEvidence on cancer drug wastage comes largely from high-income countries and generally excludes the pediatric setting. This study quantified consumption, leftover reuse and wastage in a chemotherapy compounding unit of the Brazilian public health system.MethodsProspective, observational, descriptive study covering every compounding episode performed between October and December 2024 in a public hospital serving adult oncology and adult and pediatric onco-hematology. Of 32 formulary injectable cytotoxic drugs, the 29 with activity were analyzed by quantity and cost. The daily balance was classified as reusable leftover or wastage by a 24-h stability threshold. Relative wastage (quantity discarded divided by quantity compounded) was calculated per drug.Results1298 patients were treated in 2030 compounding episodes. Compounded doses totaled 612,192 mg or IU (BRL 657,724.73), of which 5.5% by quantity came from reused leftovers. Wastage reached 53,996.45 mg or IU (BRL 30,391.78; USD 5206.84), equivalent to 8.8% of the compounded quantity, 4.6% of its value and 13.9 mg or IU per patient treated per month. Fluorouracil led both compounded quantity (29.5%) and wastage (27.1%), yet relative wastage was highest in low-volume drugs with short stability: fludarabine (158.9%), etoposide (134.0%) and azacitidine (95.5%). Pegaspargase, used predominantly in children, combined 57.5% relative wastage with the largest discard cost (BRL 15,402.00). Pertuzumab, the costliest drug compounded, generated none.ConclusionsWastage concentrated in drugs with short stability and vial sizes poorly matched to prescribed doses, whereas the greatest financial impact fell on high unit-cost biologics. Relative wastage reveals intervention targets that absolute volume does not.