Justification for initiating patiromer when restricted by prior authorization and clinical guidance in a US health care system.

BACKGROUND: In the Veterans Health Administration, patiromer is a formulary medication restricted by prior authorization and criteria-for-use (CFU). Historically, patiromer approval was restricted by step therapy, requiring prescribers to trial sodium polystyrene sulfonate (SPS). OBJECTIVE: To describe clinical scenarios leading to patiromer initiation by characterizing patient experience with primary hyperkalemia treatment modalities, especially SPS. METHODS: All veterans who initiated patiromer between January 1, 2016, and February 28, 2021, with chronic kidney disease and dispensed SPS during the 3 months preceding patiromer were included. A structured chart-review process was used to abstract prior authorization drug request notes to characterize patiromer approval and patient experience with primary pharmacotherapy. Results were reported with descriptive frequencies and proportions. RESULTS: Three hundred thirty-one veterans met inclusion criteria. Primary justification for patiromer initiation included continuation of patiromer initiated outside the Veterans Health Administration or during inpatient stay (5.7%) and SPS inventory shortage (25.4%). CFU justification was mentioned in 83.7% of notes and, among those with CFU justification, SPS treatment was documented in 68.7%. Clinician statements indicating that SPS was ineffective occurred in 65 (41.7%) and statements of safety concerns (either observed or potential) in 37 (23.7%) veterans. CONCLUSIONS: Patiromer approval is multifactorial, and clinicians often opted to avoid long-term SPS use because of safety concerns, lack of consistent availability, and concerns about its appropriateness for longterm hyperkalemia management. DISCLOSURES: Drs Patel and Sauer received funding from Otsuka Canada Pharmaceutical Inc. to study the use of patiromer in the VHA. This material is the result of work supported with resources and the use of facilities at the VA Salt Lake City Health Care System. The views expressed in this manuscript are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the US government. Drs Qualls and Pinnell are supported by the VA Advanced Fellowship Program in Medical Informatics with the Office of Academic Affiliations. This work was funded through a partnered research mechanism. Otsuka Canada Pharmaceutical Inc. was not involved in development or review of this manuscript.