Nephrotoxicity, including acquired Fanconi's syndrome, caused by adefovir dipivoxil - is there a safe dose?

ABSTRACT

WHAT IS KNOWN AND OBJECTIVE: Adefovir dipivoxil (ADV) is an oral bioavailable prodrug of adefovir that possesses potent in vitro activity against hepadnaviruses, retroviruses and herpes viruses. ADV is excreted unchanged in the urine through glomerular filtration and tubular secretion and is known to be nephrotoxic at doses of 60mg daily and above. Thus, the long-term safety of ADV, particularly nephrotoxicity, is a major concern. Our objective is to comment on the nephrotoxcicity of low-dose (10mg daily) ADV through a case report. COMMENT: The clinical features of nephrotoxicity because of ADV are described. A case report of acquired Fanconi's syndrome in a chronic hepatitis B patient treated with ADV 10mg daily is used to illustrate several key aspects. WHAT IS NEW AND CONCLUSION: Adefovir dipivoxil can be nephrotoxic at conventional dosage and therefore, patients treated with long-term ADV should have regular monitoring of renal function, and calcium and phosphate levels.