528: Guanfacine for Dexmedetomidine Withdrawal

Introduction: The use of guanfacine has been proposed to facilitate dexmedetomidine weaning in critically ill patients given its action as an alpha-2 agonist. Historically, clonidine has been used for this purpose, however its use is limited by cardiovascular effects, namely hypotension. Guanfacine is thought to be more centrally-acting compared to clonidine, theoretically reducing the comparative risk of these hypotensive adverse effects. The purpose of this medication use evaluation was to classify the current practice of guanfacine use for dexmedetomidine withdrawal at Inova Health System. Methods: A retrospective chart review of patients who received guanfacine at Inova Health System between January 1, 2023 and August 31, 2024 was performed. Eligible patients were identified via an Epic SlicerDicer report. Patients were included if they were at least 18 years of age and received guanfacine exclusively for dexmedetomidine withdrawal. Results: The cohort (n=20) was primarily female (65%) with a median age of 45 years (IQR=38-63). Of the instances evaluated (n=21), 76.2% of patients had received dexmedetomidine for at least 48 hours prior to guanfacine initiation. The guanfacine extended-release formulation was ordered in 28.6% of instances, with 66.7% of those cases deemed inappropriate for the administration route (i.e., administration via enteral feeding tubes). For the majority of patients, the guanfacine dose and frequency was titrated over time, with the most frequent starting dose as 1 mg once daily and peak dose as 2 mg twice daily. Median duration of guanfacine therapy was 8.8 days (IQR=3.9-15.6) and median duration of dexmedetomidine administration from the start of guanfacine until either dexmedetomidine or guanfacine discontinuation was 85 hours (IQR=18-177). Conclusions: The results of this evaluation reveal a lack of standardized guanfacine dosing strategies in dexmedetomidine weaning, suggesting an opportunity for protocol development. Additionally, the findings suggest an education opportunity for providers on ensuring the appropriate guanfacine formulation is ordered for the planned route of administration. Immediate future directions for this project include a research project designed to evaluate the comparative efficacy of dexmedetomidine weaning strategies.