Pancreatitis
In patients with HIV infection during therapy with hydroxyurea and didanosine, with or without stavudine, fatal and nonfatal cases of pancreatitis have occurred.
Hydroxyurea is not indicated for the treatment of HIV infection; however, if patients with HIV infection are treated with hydroxyurea, and in particular, in combination with didanosine and/or stavudine, close monitoring for signs and symptoms of pancreatitis is recommended. Permanently discontinue therapy with hydroxyurea in patients who develop signs and symptoms of pancreatitis.
Hepatotoxicity
Hepatotoxicity and hepatic failure resulting in death have been reported during postmarketing surveillance in patients with HIV infection treated with hydroxyurea and other antiretroviral drugs. Fatal hepatic events were reported most often in patients treated with the combination of hydroxyurea, didanosine, and stavudine. Avoid this combination.
Peripheral Neuropathy
Peripheral neuropathy, which was severe in some cases, has been reported in patients with HIV infection receiving hydroxyurea in combination with antiretroviral drugs, including didanosine, with or without stavudine.
XROMI is not approved in males or females of reproductive potential.
Infertility
Males
Based on findings in animals and humans, male fertility may be compromised by treatment with XROMI. Azoospermia or oligospermia, sometimes reversible, has been observed in men. [see Nonclinical Toxicology (13.1)].
Absorption
Following oral administration of XROMI, hydroxyurea reaches peak plasma concentrations in 0 to 2 hours. Mean peak plasma concentrations and AUCs increase more than proportionally with increase of dose.
Effect of Food
There are no data on the effect of food on the absorption of hydroxyurea.
Distribution
Hydroxyurea distributes throughout the body with a volume of distribution approximating total body water.
Hydroxyurea concentrates in leukocytes and erythrocytes.
Elimination
Metabolism
Up to 60% of an oral dose undergoes conversion through saturable hepatic metabolism and a minor pathway of degradation by urease found in intestinal bacteria.
Excretion
In patients with sickle cell anemia, the mean cumulative urinary recovery of hydroxyurea was about 40% of the administered dose.
Specific Populations
Renal Impairment
The effect of renal impairment on the pharmacokinetics of hydroxyurea was assessed in adult patients with sickle cell disease and renal impairment.
Patients with normal renal function (creatinine clearance [CrCl] >80 mL/min), mild (CrCl 50-80 mL/min), moderate (CrCl =30-<50 mL/min), or severe (<30 mL/min) renal impairment received a single oral dose of 15 mg/kg hydroxyurea.
Creatinine clearance values were obtained using 24-hour urine collections. Patients with ESRD received two doses of 15 mg/kg separated by 7 days; the first was given following a 4-hour hemodialysis session, the second prior to hemodialysis.
The exposure to hydroxyurea (mean AUC) in patients with CrCl <60 mL/min and those with ESRD was 64% higher than in patients with normal renal function (CrCl >60 mL/min).
[see Dosage and Administration (2.2) and Use in Specific Populations (8.6)].
Pediatric Patients
The model estimated steady state exposures (AUC) in pediatric patients receiving a daily dose of 15 mg/kg is lower in patients aged 6 months to <2 years by 40% compared to adults receiving the same dose (XROMI is not approved for use in adults).