Cardiovascular and Adverse Effects of Glucagon for the Management of Suspected Beta Blocker Toxicity: a Case Series.

BACKGROUND: Although glucagon use in beta blocker toxicity has been recommended for many years, evidence for its safety and efficacy in humans is limited. This study aims to determine the magnitude of effect of glucagon on heart rate (HR) and systolic blood pressure (SBP) in patients with suspected beta blocker toxicity and describe potential adverse effects of the medication.

METHODS: We conducted a retrospective, multi-center case series of patients greater than 12 years of age who received glucagon for suspected beta blocker toxicity. The primary outcome was the mean difference in HR from immediately pre- to 20-minutes post-glucagon administration. Secondary outcomes included the median difference in SBP, and occurrence of nausea, vomiting, and hyperglycemia.

RESULTS: A total of 107 patients met inclusion criteria accounting for 144 glucagon orders. The mean difference in HR from pre- to post-glucagon administration was 4 bpm ± 10.6 (95% CI [2.25-5.76], p < 0.001). The median difference (IQR) in SBP was 4.5 (- 6 to 16) mmHg (p = 0.004). Similar increases were observed when patients receiving concomitant vasopressors were excluded. A total of nine glucagon administrations (6.3%) were associated with nausea and 14 (9.7%) with vomiting; however, 52 doses (36.1%) were administered concomitantly with antiemetic medications. Fifteen administrations (10.4%) were associated with hyperglycemia.

CONCLUSION: Glucagon administration was associated with a statistically significant increase in HR, but a small absolute difference of uncertain clinical significance. A similar observation was noted for SBP. Few patients experienced adverse events.