Severe acute hypokalaemia associated with piperacillin/tazobactam in an HIV-infected patient under antiretroviral therapy with tenofovir alafenamide: case report and literature review.

Piperacillin/tazobactam is a commonly prescribed antimicrobial agent. Tenofovir alafenamide (TAF) is increasingly being used in antiretroviral therapy (ART) of HIV. Herein we report a case of a 57-year-old male with AIDS receiving TAF-containing ART in whom severe refractory hypokalaemia developed after coadministration of piperacillin/tazobactam for suspected hospital-acquired infection. Upon withdrawal of piperacillin/tazobactam, serum potassium concentrations returned to normal within 2 days. Hypokalaemia is a rare adverse effect of piperacillin/tazobactam and may be aggravated with the underlying use of TAF. We also reviewed past reported cases of hypokalaemia after piperacillin/tazobactam administration. We want to highlight that a more cautious approach should be considered when combining piperacillin/tazobactam and TAF in clinical practice.