Scientific Poster Session IV - Original Research

Original Research
  Tuesday, November 14, 2023
  08:30 AM–10:00 AM

Abstract

Introduction: The American Society of Transplant recommends Pneumocystis jirovecii pneumonia (PJP) prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX) after lung and heart-lung transplant (LTx). The optimal dosing regimen is not known.

Research Question or Hypothesis: This study compared the incidence of hyperkalemia between TMP-SMX double strength Monday, Wednesday, Friday (DS MWF) and single strength (SS) daily prophylactic regimens in lung and heart-lung transplants to provide greater guidance on dosing and safety.

Study Design: This was a retrospective chart review of 207 adult LTx recipients comparing PJP prophylaxis with DS MWF regimen from 1/2016-12/2019 against SS daily from 1/2019-12/2022.

Methods: The primary endpoint was incidence of hyperkalemia as measured by serum potassium level > 5.5 mEq/L within the first-year post-transplant. Secondary safety endpoints included number of patients with at least one event of severe hyperkalemia requiring intervention, types of interventions used, and number of patients who discontinued TMP-SMX due to hyperkalemia. Secondary efficacy endpoints included incidence of PJP, Nocardia, or Toxoplasma infections. Level of significance (alpha) was set at 0.05.

Results: Compared to DS MWF (n=117), the SS daily (n=90) regimen had a statistically significant higher number of the following: hyperkalemic incidences (545 vs 895, p=0.01), patients who had at least one event of hyperkalemia (74% vs 89%, p=0.03), who had at least one event of severe hyperkalemia (45% vs 58%, p <0.001), and who discontinued TMP-SMX due to hyperkalemia (1.7% vs 6.7%, p=0.03). There were no significant differences between groups for potassium and glomerular filtration rate (GFR) median levels at months 3, 6, and 12 and no PJP, Toxoplasma, or Nocardia infections.

Conclusion: SS daily was associated with a higher incidence of hyperkalemia as compared to DS MWF during the first year of post-lung and heart-lung transplants. Both regimens had similar efficacy in preventing PJP, nocardia and toxoplasma infections.

Presenting Author

Allison Vu PharmD
Stanford Health Care

Authors

Prasannaraddi Alavandi PharmD
Stanford Health Care

Roy Lee PharmD, BCPS
Stanford Health Care

Erik Henricksen PharmD, BCPS
Stanford Health Care

Shravani Pasupneti MD
Stanford Health Care