Renal dysfunction in chronic hepatitis B patients treated with adefovir dipivoxil

Abstract

Renal dysfunction has been reported in patients treated with adefovir dipivoxil (ADV); however, its incidence and clinical importance may be underappreciated given the lack of long-term follow-up and data outside of a clinical trial setting. Our goal was to examine the severity and incidence of renal dysfunction in a real-life setting for patients treated with ADV and whose baseline estimated glomerular filtration rate (eGFR) was >50 mL/minute. We performed a cohort study of 290 chronic hepatitis B patients: 145 patients treated with 10 mg ADV and 145 patients unexposed to ADV at two community clinics, who were matched for age (+/-10 years), sex, and baseline eGFR. The exposed and unexposed populations were well-matched with a similar mean age (46-47 years), proportion of male patients (76.5%), baseline serum creatinine (0.97-0.99 mg/dL), and baseline creatinine clearance (85.0-85.4 mL/minute). The incidence density for renal dysfunction defined by treatment termination and/or development of eGFR < or =50 mL/minute was five cases per 100 patient-years in the exposed group compared with 1.36 cases per 100 patient-years in the unexposed group (P = 0.02). The relative risk of exposed to unexposed was 3.68 (95% confidence interval 1.1-19.3). On Cox proportional hazard analysis also inclusive of sex, ADV was a significant predictor of significant renal dysfunction (hazard ratio [HR] 3.94, P = 0.03). There were also significant trends for age >50 years (HR 3.49, P = 0.087), mild renal impairment at baseline (HR 4.49, P = 0.073), and hypertension and/or diabetes mellitus (HR 2.36, P = 0.074). ADV is an independent predictor for significant deterioration of renal function. Patients on ADV should be monitored, especially patients who are older, have baseline renal insufficiency, or have hypertension and/or diabetes mellitus.