Dose equivalence between metaraminol and norepinephrine in critical care

Abstract

Mean arterial pressure (MAP) and infusion doses for both drugs were collected at hourly intervals; 2 hours before to 5 hours after switching from metaraminol monotherapy to norepinephrine monotherapy. The conversion dose ratio was defined as the ratio of metaraminol (μg.kg À1 .min -1) : norepinephrine (μg.kg À1 .min À1 ) required to achieve a similar MAP.Results: A total of 43 out of 144 eligible patients were included. The median age was 68 years (IQR 56-76) and 22 (51%) were male. There was no significant difference between the baseline MAP during metaraminol monotherapy (median 71 mm Hg, IQR 66-76) and the post-transition MAP during norepinephrine monotherapy (median 70 mm Hg, IQR 66-73) (P = .09). The median conversion dose ratio between metaraminol and norepinephrine was 13 (IQR 7-24). In the sensitivity analyses, the median conversion dose ratio using the maximum and the mean norepinephrine infusion dose was 8 (IQR 5-16) and 12 (IQR 8-23), respectively. Conclusion:A conversion dose ratio of 10:1 (metaraminol μg.kg À1 .min À1 :norepinephrine μg.kg À1 .min À1 ) may be used in critically ill patients with shock to account for ease of calculations and variability of the conversion ratio in the primary and sensitivity analyses.

Assessment of depth of sedation using Bispectral Index™ monitoring in patients with severe traumatic brain injury in UK intensive care units

“…Participants on alternative vasopressors, such as metaraminol, were converted to noradrenaline (norepinephrine) equivalents using previously published dosing equivalents. 20 …”

The use of metaraminol as a vasopressor in critically unwell patients: a narrative review and a survey of UK practice

“…Thirteen other articles that were excluded [21][22][23][24][25][26][27][28][29][30][31][32], as they did not meet the inclusion criteria. Four were either prospective or retrospective observational studies regarding metaraminol use in combination with other vasopressors, metaraminol dosing, frequency of metaraminol use [21,23,24,33,34]. Four were case reports, highlighting use of metaraminol for shock of different etiologies [22,27,28,31].…”