Inclusion Criteria

INCLUSION CRITERIA:

Age: Two age groups will be enrolled and studied separately.

Group 1: 4 months to less than 2 years.

Group 2: 2 years to less than 21 years.

Gender and Ethnicity: There will be no restriction as to genderor ethnicity. A resonable
effort will be made to include chldren of both genders and all ethnic backgrounds.

HIV-infected children between the ages of 4 months and 21 years.

An indication for treatment with antiretrovirals.

One of the following: Children failing current treatment after at least 12 weeks of
therapy as defined by the most recent Guidelines for the Use of Antiretroviral Agents in n
Pediatric HIV Infection or accepted practice OR Intolerant to or are showing evidence of
toxicity from other antiretroviral treatments.

HIV RNA greater than or equal to 5,000 copies per/mL within the past 3 months (may be from
outside institution).

Women of childbearing age must agree to avoid becoming pregnant while on study and for 4
months afterwards.

Hematologic Function:

Total WBC greater than 1,500/mm(3),

Absolute neutrophil count greater than 750/mm(3),

Hemoglobin greater than 8.0 gm/dL, and

Platelet count greater than 75,000/mm(3) at study entry.

Hepatic Function:

Liver transaminases must be less than or equal to 3.0 times the upper limit of normal;

Serum amylase less than 1.5 times the upper limit of normal and if abnormal, fractionated
pancreatic amylase less than 45 U/L;

Lipase less than 1.5 times the upper limit of normal;

Creatinine phosphokinase (CPK) less than 2.5 times the upper limit of normal.

Renal Function:

Patients must have an age-adjusted normal serum creatinine OR a creatinine clearance
greater than or equal to 70 mL/min/1.73:

EXCLUSION CRITERIA:

Therapeutic regimens including:

Immunomodulating agents (within 30 days of entry), other than GCSF, erythropoeitin,
corticosteroids, IVIG, or anti-D;

Treatment with chemotherapeutic agents (including hydroxyurea) or radiation therapy within
the past 6 weeks;

Current chronic use of medications known to inhibit or induce cytochrome P450, including
but not limited to: isoniazid, rifampin, rifabutin, astemizole, terfenadine, cisapride,
triazolam, midazolam, nifedipine, diltiazem, verapamil, cimetidine, dexamethasone,
carbamazepine, phenytoin, phenobarbital, propoxyphene, quinidine, amiodarone, or ergot
alkaloids, azole antifungals (ketoconazole, fluconazole, itraconazole), or macrolide
antibiotics (erythromycin, clarithromycin);

Current use of highly plasma protein bound drugs including but not limited to, warfarin
and phenytoin;

Current use, or use within the last 28 days, of any investigational agent.

Clinically significant, unrelated systemic illness (serious infections or significant
cardiac, pulmonary, hepatic or other organ dysfunction) which in the judgement of the
Principal Investigator or Chairperson would compromise the patient's ability to tolerate
this therapy or is likely to interfere with the study procedures or results will be
excluded.

Weighting less than 10 kg.

Pregnant or breast feeding females will be excluded.