- Busulfan dosing will resume starting on day -8 and will be given IV q6h for an additional 15 doses (total 16 doses). Patients at UCSF will receive busulfan chemotherapy on the 11 Long Adult Inpatient Unit. Dose #2 will be administered at approximately 8 pm. This dose will be adjusted based on target dose level and PK data results following dose #1. The second dose will not be given until the PK data is available from dose #1.