Hypokalemic paralysis and proximal renal tubular acidosis secondary to tenofovir-induced Fanconi syndrome: A contributing cause of death

Nucleotide reverse transcriptase inhibitors (NRTIs, primarily cidofovir and adefovir, less likely tenofovir) pose a well-known risk of nephrotoxicity. Acute renal failure, nephrogenic diabetes insipidus (NDI), and Fanconi syndrome (FS) are the primarily reported renal adverse effects associated with NRTIs. In this report, we describe a case of a 52-year-old female who presented to the outpatient department of a tertiary-care facility with polyuria, polydipsia, convulsions, myalgias, and hypokalemic paralysis (quadriparesis) after 10 months exposure to tenofovir disoproxil fumarate (TDF), which she was taking for HIV and Hepatitis-B virus coinfection. The patient developed hypokalemic paralysis and proximal renal tubular acidosis (pRTA) with normal anion gap hyperchloremic metabolic acidosis. On evaluation, renal tubulopathy was evident, which was resolved post-TDF discontinuation and therapeutic corrections. A diagnosis of TDF-induced FS, pRTA, and NDI were considered, as there were no clear alternative explanations. This report also highlights the characteristics of TDF-induced FS from the published case reports in the Indian context.