#2986 Patiromer for hyperkalemia in the early post-transplant period
Authors: Nava-Chávez Coraima Claudia , Macías Nicolás , Rodriguez Marisa , Villa-Valdés Miguel , Gueorguieva Antonia , Bascuñana Arturo , Pervan Emina , Encalada Landires Miguel Ángel , Ortiz Jorge Armando Torres , Sanchez Gema , Goicoechea Marian 
Published: May 2024

Abstract

Background and Aims
Hyperkalemia is a serious condition among kidney transplant (KT) recipients, which can lead to life-threatening complications such as cardiac arrhythmias.
Following kidney transplantation, the causes of hyperkalemia are multifactorial owing to graft function, excess potassium repletion, comorbidities, and medications used in the peri- and post-operative setting.
The risk for hyperkalemia is increased immediately post-transplantation, particularly in those with suboptimal graft function and higher calcineurin inhibitors levels. A rapidly rising potassium refractory to medical therapy can be an indication for dialysis.
Managing hyperkalemia after kidney transplantation is associated with increased morbidity and healthcare costs. In that manner, newer alternatives such as patiromer and sodium zirconium cyclosilicate have emerged due to their potentially superior efficacy and safety profiles.

Method
This is an observational, retrospective, single-center study aimed to evaluate the efficacy and safety of patiromer for hyperkalemia management in adult transplant recipients over the first 3 months post-transplant period, between January and December 2022 (since patiromer is available in our hospital pharmacy). We included all the kidney transplant recipients of our hospital, with the exception of those with primary graft failure. Information concerning the donor, recipient, graft, drugs pre and post-transplant, fluid therapy, transfusions, and blood tests (ions, blood gases, glycemia, kidney function measurements, anticalcineurin inhibitors levels) were collected. Patiromer was administered in a single-daily dose, diluted in 250 cc of water, in the afternoon, at least 2 hours separated of other drugs.

Results
In total, 69 recipients were included in the analysis. 94% were from deceased donors and 54% from donation after cardiac death. The average age of the entire cohort was 55 years and 66% were male. Medical history of each KT recipients reveal that 89% has hypertension, 32% diabetes, and 35% previous cardiopathy. Hypertension treatment before the KT included beta-blockers (39%) and angiotensin-converting enzyme inhibitors (37%).
The incidence of hyperkalemia (K ≥ 5.5 mmol/L) was 29.7% in the first three months, mostly in the first week (21.6%). Patiromer was administered to 37% of them. For the 88.5% an initial dose of 8.4 g/day was enough. Although, 27% required an increase of the dose to 16.8 g/day and 8% to 25.2 g/day. The changes in serum potassium levels following the first patiromer dose are shown in Graphic 1. The mean time duration of the patiromer treatment was 14.5 days (3.7-36.7). However, 27% continue with patiromer beyond three months.
There was no significant difference in the dose/levels of tacrolimus neither in the serum magnesium levels between patients with or without patiromer.
No gastrointestinal complications were observed following the use of patiromer.

Conclusion
Patiromer may play an important role in the management of hyperkalemia over the first weeks after KT, allowing a significant and sustained reduction of the serum potassium levels, although additional long-term studies are necessary to confirm these effects.