outpatient follow-up phase of the study Zidovudine will be dispensed by the 
study center pharmacy in limited quantities (two-four week supply) to provide 
an accurate accounting of compliance at the time of each follow-up clinic 
visit. 
2. Dosage and Administration 
a. Pretransplantation Treatment 
Two weeks prior to bone marrow transplantation (day-14 through day 0), 
patients will receive Zidovudine therapy at 5 mg/kg IV every four hours, with 
zidovudine administered over one hour IV. 
b. Transplantation Therapy 
At the time of the bone marrow transplantation (day 0) the Zidovudine dose 
will be reduced to 2.25 mg/kg IV every four hours (after infusion of the 
donor marrow). 
c. Posttransplantation Therapy 
Conversion to an oral regimen will be initiated if the patient is able to tolerate 
oral medications and is able to be discharged to the outpatient department. 
The dose TV will be reduced by 50% (1.13 mg/kg) and a 48 hour trial of 
Zidovudine 100 mg p.o. every four hours (1.35 mg/kg/q 4 hours) will be 
initiated. If the patient is able to tolerate the oral medication, then the IV 
dosing can be discontinued. 
The oral dose will be continued for a minimum of twelve months. After this 
period the drug will be continued at the discretion of the principal investigator 
with mutual consent of the patient. 
3. Zidovudine Dose Modifications 
a. Discontinuation of Zidovudine 
1 . Life threatening anaphylactic reaction secondary to Zidovudine. 
2. Severe bone marrow toxicity as defined by the failure of donor bone 
marrow to engraft after marrow infusion will necessitate Zidovudine 
discontinuation. Zidovudine will be discontinued if the absolute 
neutrophil count (ANC) is less than the indicated value at any of the 
three evaluation points posttransplant (Table 2). 
TABLE 2 
Stopping Criteria for Zidovudine Administration 
Day of Evaluation Posttransplant Sto pping Criteria 
Day 18 ANC <100 
Day 22 ANC < 200 
Day 30 ANC <500 
These stopping criteria were formulated by reviewing rates of 
engraftment in 44 patients receiving HLA-identical allogeneic marrow 
transplants for leukemia/lymphoma. These patients received 
cyclosporine only for graft-versus-host disease prophylaxis. Forty- 
three of forty-four patients attained an ANC of 100 by day 17 
[624] 
Recombinant DNA Research, Volume 15 
