# Clinical Characteristics and Predictors of Hypokalemia in Patients Receiving Piperacillin/Tazobactam: A Retrospective Observational Audit

## TL;DR

This study found that low potassium levels are common in patients taking piperacillin/tazobactam, especially in women and those with low initial potassium.

## Contribution

The study provides new clinical insights into the incidence and risk factors for hypokalemia during piperacillin/tazobactam therapy.

## Key findings

- Hypokalemia incidence was highest around Day 5 of piperacillin/tazobactam therapy.
- Female patients and those with baseline potassium <4.0 mmol/L were more likely to develop hypokalemia.
- Potassium supplementation improved levels, showing its effectiveness in recovery.

## Abstract

Hypokalemia is a clinically relevant electrolyte disturbance that may develop during treatment with piperacillin/tazobactam. Although often described as uncommon, emerging clinical experience suggests that the true incidence may be higher, particularly among hospitalized patients receiving prolonged therapy. This retrospective observational audit evaluated the incidence, severity, and risk factors associated with hypokalemia in adult inpatients treated with piperacillin/tazobactam at Mater Dei Hospital. Medical records of 62 adult patients who received piperacillin/tazobactam for at least three consecutive days between May 1, 2024, and August 31, 2024, were reviewed. Serum potassium values, demographic data, duration of therapy, comorbidities, and potassium supplementation patterns were examined. Hypokalemia developed progressively with treatment duration, with the highest incidence observed around Day 5 of therapy. Female patients and those with baseline potassium levels below 4.0 mmol/L demonstrated a greater predisposition to developing hypokalemia. Although hypokalemia was observed during therapy, potassium supplementation generally led to improvement in serum potassium levels, indicating that supplementation was effective in supporting biochemical recovery. Higher initial potassium levels appeared to be protective, highlighting the importance of early risk assessment and optimization of baseline potassium. This analysis emphasizes that hypokalemia is a relatively common occurrence in patients treated with piperacillin/tazobactam in routine clinical practice. The findings support the need for proactive monitoring, identification of high-risk groups, and preventive strategies, such as optimizing baseline potassium and closer surveillance during the first week of therapy, to reduce the likelihood of clinically significant electrolyte disturbances.