The renal tolerance of low-dose adefovir dipivoxil by lamivudine-resistant individuals co-infected with hepatitis B and HIV

Background. Adefovir (ADV), an orally administered nucleotide analogue active against hepadnaviruses, retroviruses and herpes viruses was shown to be effective in HIV-infected patients, but the prevalence of nephrotoxicity with doses of 60-120 mg/day was considered unacceptable. Recently, lower doses of ADV were shown to be effective for the treatment of HIV-1 patients with chronic lamivudine (LAM)resistant hepatitis B. Methods. In a cohort of 35 patients infected with both HIV-1 and LAM-resistant hepatitis B virus, we investigated the renal tolerance of a once-daily dose of ADV 10 mg over 52 weeks. Their mean baseline creatinine clearance was within the normal range (105 +/- 3 ml/min/1.73 m(2)). No patient had significant changes in renal function or electrolyte balance secondary to ADV treatment. Results. Transient increases in serum creatinine, which resolved by the end of the study were noted in two patients and three developed proteinuria, which was felt to be unrelated to ADV treatment. The cohort's mean serum phosphate level, 2.45 +/- 0.09 mg/dl at baseline, did not change significantly under treatment (2.66 +/- 0.12 mg/dl at week 52, P = NS). Conclusions. Our study shows that ADV dosed at 10 mg/day for the treatment of LAM-resistant chronic hepatitis B in patients co-infected with HIV is not associated with renal tubular dysfunction or a significant change in renal function.