Pharmacoepidemiology of metaraminol in critically ill patients with shock in a tertiary care hospital

Metaraminol is increasingly used as a vasopressor in critically ill patients. Nevertheless, there remains limited evidence to support its use in international guidelines for management of shock. The aim of the study was to describe the pharmacoepidemiology of metaraminol in critically ill patients with shock. A retrospective observational study was conducted in an intensive care unit (ICU) in Sydney, Australia. Patients admitted during a 1-year time frame who received metaraminol intravenous infusions for management of shock were included. A total of 152 patients were included. When metaraminol was used, it was the most common first-line vasopressor started for management of shock (97%, n = 147) and was used as monotherapy in 53% (n = 81) of patients. The median duration of metaraminol infusion in the ICU was 7 h (interquartile range [IQR] = 3 to 19), and the median maximum metaraminol infusion rate in the ICU was 4.0 mg/h (IQR = 2.5 to 6.0). Peripheral vasopressor infusions were used in 96% (n = 146/152) of patients for a median duration of 7 h (IQR = 2 to 18). In all these cases, the peripheral vasopressor used was metaraminol (100%, n = 146/146). Patients were commonly switched from metaraminol to noradrenaline infusions after insertion of a central venous catheter (R2 = 0.89). Patients treated with metaraminol monotherapy had a lower Acute Physiology and Chronic Health Evaluation III score (58 vs 68; median difference = −9, 95% confidence interval = −16 to −3; p