Costs and outcomes with once-daily versus every-six-hour intravenous busulfan in allogeneic hematopoietic cell transplantation.

•Every-24-hour (q24h) dosing of i.v. busulfan reduced drug waste compared with every-6-hour (q6h) dosing.•Reduced busulfan drug waste led to a cost savings of nearly $20,000 USD per patient.•Clinical outcomes were equivocal or improved with q24h dosing compared with q6h dosing.