Mary Medley, PharmD
Ascension Saint Thomas West
Memphis, Tennessee
Disclosure information not submitted.
Adam Wiss, PharmD, BCCCP
Neurointensive Care Unit Pharmacist
Ascension Saint Thomas Hospital West, United States
Disclosure information not submitted.
Brooke Bibb, PharmD
Clinical Pharmacist
Ascension Saint Thomas Hospital West, United States
Disclosure information not submitted.
Title: Guanfacine to Aid in Weaning Dexmedetomidine for Sedation in the ICU
Introduction: Prolonged infusions of dexmedetomidine may precipitate withdrawal and delay transition to a lower level of care. Clonidine has been utilized to wean dexmedetomidine, but is limited by hypotension and bradycardia. Guanfacine may provide the desired level of sedation with less hemodynamic events, due to preferential receptor affinity of alpha-2B > alpha 2A. The purpose of this study was to analyze guanfacine and dexmedetomidine practices for sedation in the ICU.
Methods: This single-center, retrospective chart review included adults treated with dexmedetomidine and guanfacine for sedation in the ICU between January 2017 and September 2020. Those who received < 2 doses of guanfacine, received guanfacine prior to initiating dexmedetomidine, were being treated for alcohol withdrawal, or were receiving paralytics were excluded. The primary objective was to evaluate response to guanfacine at 24 hours. Response was defined as discontinuation of dexmedetomidine within 24 hours of initiating guanfacine without augmenting ancillary psychoactive medications. Secondary objectives included rates of hypotension and bradycardia.
Results: Forty-eight patients were included in the analysis. Twenty-one patients (43.8%) responded to therapy. Of the 27 nonresponders, 9 patients had an increase in psychoactive medication(s) and 18 patients continued on dexmedetomidine at 24 hours. Overall, 30 patients (62.5%) were weaned from dexmedetomidine within 24 hours. Notable characteristics between the responder and nonresponder groups were as follows: mechanical ventilation (29% vs. 56%, p=0.06), baseline CAM-ICU positive (57% vs. 83%, p=0.08), time on dexmedetomidine prior to guanfacine initiation in hours (59 [IQR, 45-82] vs. 36 [IQR, 16-80], p=0.06), and dexmedetomidine dose at guanfacine initiation in mcg/kg/hr (0.2 [IQR, 0-0.4] vs. 0.6 [IQR, 0.2-0.9], p=0.01). In nonresponders, the median time to dexmedetomidine discontinuation was 73 hours [IQR, 30-111]. The majority were treated with guanfacine 1 mg twice daily. Hypotension occurred in 3 (14%) patients in the responder group and 3 (11%) patients in the nonresponder group (p >0.99). Bradycardia occurred in 1 nonresponder.
Conclusions: Guanfacine may be a safe and effective strategy to assist dexmedetomidine weaning in some patients and further study is warranted.