Switching tenofovir disoproxil fumarate to tenofovir alafenamide results in a significant decline in parathyroid hormone levels: uncovering the mechanism of tenofovir disoproxil fumarate-related bone loss?

: An increasing number of patients have been switched from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide because of its improved bone safety profile, although the pathophysiological mechanism is not fully understood. We show that serum parathyroid hormone levels drop significantly after the switch from TDF to tenofovir alafenamide. This observation supports the theories that TDF-related bone loss is parathyroid hormone-driven and that this effect is dose-dependent.