As an adjunct therapy with cyclophosphamide for conditioning prior to bone marrow transplantation in adults and children >12 kg, intravenous (IV) busulfan (Bulsulfex) is dosed at 0.8 mg/kg every six hours for 16 doses (four days). IV busulfan is usually administered over two hours. Both IV and oral formulations require prophylactic antiemetic agents administered prior to the busulfan dose and scheduled antiemetics administered thereafter. Oral bioavailability of busulfan shows a large interindividual variation. Taking busulfan on an empty stomach is recommended to reduce the risk of nausea and emesis.