Background and importance Hyperkalaemia is an electrolyte disorder, common among patients with chronic kidney disease, diabetes mellitus or heart failure (HF). Its occurrence is associated with an increase in mortality risk. Patiromer was recently approved by the Europaan Medicines Agency (EMA) for the treatment of hyperkalaemia, and is under additional monitoring, allowing quick identification of possible new safety information.

Aim and objectives To assess the adverse events (AE) of patiromer in HF patients with chronic hyperkalaemia.

Material and methods Prospective observational study that included HF patients treated with patiromer to optimise kaleemia and renin angiotensin aldosterone system inhibitor (RAASi) medication, followed in a pharmaceutical consultation between November 2020 and September 2021. A questionnaire evaluating the occurrence of adverse events was applied to all patients on days 1, 3, 7 and 30 after starting therapy and thereafter monthly, or whenever a clinical change was considered relevant. The clinically significant AE were reported to our National Pharmacovigilance System (NPS).

Results During the study period, 19 patients were included, 15 males (78.9%) with a mean age of 69.1±10.2 years. A total of 13 AE occurred in 11 patients. Expected AE such as gastrointestinal disorders (diarrhoea (n=4), flatulence (n=1)), hypomagnesemia (n=3) and cases of unexpected anaemia (n=1), CKD worsening (n=1) and metabolic acidosis (n=3) were reported. Causality has already been confirmed by the NPS in 4 reported AE: 2 metabolic acidosis were considered possible, 1 diarrhoea and 1 flatulence were considered probable. Patiromer was discontinued in 7 patients due to AE, 2 of wich resulted in hospitalisation (metabolic acidosis).

Conclusion and relevance As of June 2021, the World Health Organization (WHO) has received 10 reports of metabolic acidosis associated with patiromer, including the 2 reported in this study. Despite this AE being unexpected, these reports raise concerns and can lead to safety signal and new recommendations for patiromer’s use. These preliminary results prove that establishing pharmacovigilance networks, particularly for new drugs, prescribed to patients who are often comorbid, is indispensable to assure safe healthcare in the real world.

References and/or acknowledgements 1. Schulz M, Griese-Mammen N, Anker SD, Koehler F, Ihle P, Ruckes C, et al. Pharmacy-based interdisciplinary intervention for patients with chronic heart failure: results of the PHARM-CHF randomized controlled trial. Eur J Heart Fail 2019;21(8):1012–21.

Conflict of interest No conflict of interest