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Busulfex Dosage

Generic name: busulfan
Dosage form: injection

The information at is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist.

When BUSULFEX (busulfan) Injection is administered as a component of the BuCy conditioning regimen prior to bone marrow or peripheral blood progenitor cell replacement, the recommended doses are as follows:

Adults (BuCy2)

The usual adult dose is 0.8 mg/kg of ideal body weight or actual body weight, whichever is lower, administered every six hours for four days (a total of 16 doses). For obese, or severely obese patients, BUSULFEX should be administered based on adjusted ideal body weight. Ideal body weight (IBW) should be calculated as follows (height in cm, and weight in kg): IBW (kg; men)=50+0.91× (height in cm -152); IBW (kg; women)=45+0.91× (height in cm -152). Adjusted ideal body weight (AIBW) should be calculated as follows: AIBW= IBW +0.25× (actual weight -IBW). Cyclophosphamide is given on each of two days as a one‑hour infusion at a dose of 60 mg/kg beginning on BMT day –3, no sooner than six hours following the 16th dose of BUSULFEX.

BUSULFEX clearance is best predicted when the BUSULFEX dose is administered based on adjusted ideal body weight. Dosing BUSULFEX based on actual body weight, ideal body weight or other factors can produce significant differences in BUSULFEX (busulfan) Injection clearance among lean, normal and obese patients.

BUSULFEX should be administered intravenously via a central venous catheter as a two‑hour infusion every six hours for four consecutive days for a total of 16 doses. All patients should be premedicated with phenytoin as busulfan is known to cross the blood brain barrier and induce seizures. Phenytoin reduces busulfan plasma AUC by 15%. Use of other anticonvulsants may result in higher busulfan plasma AUCs, and an increased risk of VOD or seizures. In cases where other anticonvulsants must be used, plasma busulfan exposure should be monitored (See DRUG INTERACTIONS). Antiemetics should be administered prior to the first dose of BUSULFEX and continued on a fixed schedule through administration of BUSULFEX. Where available, pharmacokinetic monitoring may be considered to further optimize therapeutic targeting.


The effectiveness of BUSULFEX in the treatment of CML has not been specifically studied in pediatric patients. For additional information see Special Populations -Pediatric section.

Preparation and Administration Precautions


An administration set with minimal residual hold-up volume (2-5 cc) should be used for product administration.

As with other cytotoxic compounds, caution should be exercised in handling and preparing the solution of BUSULFEX. Skin reactions may occur with accidental exposure. The use of gloves is recommended. If BUSULFEX or diluted BUSULFEX solution contacts the skin or mucosa, wash the skin or mucosa thoroughly with water.

BUSULFEX is a clear, colorless solution. Parenteral drug products should be visually inspected for particulate matter and discoloration prior to administration whenever the solution and container permit. If particulate matter is seen in the BUSULFEX vial the drug should not be used.

Preparation for Intravenous Administration

BUSULFEX must be diluted prior to use with either 0.9% Sodium Chloride Injection, USP (normal saline) or 5% Dextrose Injection, USP (D5W). The diluent quantity should be 10 times the volume of BUSULFEX, so that the final concentration of busulfan is approximately 0.5 mg/mL. Calculation of the dose for a 70 kg patient, would be performed as follows:

(70 kg patient) × (0.8 mg/kg) ÷ (6 mg/mL) =9.3 mL BUSULFEX (56 mg total dose).

To prepare the final solution for infusion, add 9.3 mL of BUSULFEX to 93 mL of diluent (normal saline or D5W) as calculated below:

(9.3 mL BUSULFEX) × (10) =93 mL of either diluent plus the 9.3 mL of BUSULFEX to yield a final concentration of busulfan of 0.54 mg/mL (9.3 mL ×6 mg/mL ÷102.3 mL =0.54 mg/mL).

All transfer procedures require strict adherence to aseptic techniques, preferably employing a vertical laminar flow safety hood while wearing gloves and protective clothing.

DO NOT put the BUSULFEX into an intravenous bag or large-volume syringe that does not contain normal saline or D5W. Always add the BUSULFEX to the diluent, not the diluent to the BUSULFEX. Mix thoroughly by inverting several times.

Infusion pumps should be used to administer the diluted BUSULFEX solution. Set the flow rate of the pump to deliver the entire prescribed BUSULFEX dose over two hours. Prior to and following each infusion, flush the indwelling catheter line with approximately 5 mL of 0.9% Sodium Chloride Injection, USP or 5% Dextrose Injection, USP. DO NOT infuse concomitantly with another intravenous solution of unknown compatibility. WARNING: RAPID INFUSION OF BUSULFEX HAS NOT BEEN TESTED AND IS NOT RECOMMENDED.