A pilot, feasibility, randomised controlled trial of midodrine as adjunctive vasopressor for low-dose vasopressor-dependent hypotension in intensive care patients: The MAVERIC study

The Impact of Midodrine Tapering Versus Nontapering Regimens on the Clinical Outcomes of Critically Ill Patients: A Retrospective Cohort Study

BACKGROUND

Midodrine has been used in the intensive care unit (ICU) setting to reduce the time to vasopressor discontinuation. The limited data supporting midodrine use have led to variability in the pattern of initiation and discontinuation of midodrine.

OBJECTIVES

To compare the effectiveness and safety of 2 midodrine discontinuation regimens during weaning vasopressors in critically ill patients.

METHODS

A retrospective cohort study was conducted at King Abdulaziz Medical City. Included patients were adults admitted to ICU who received midodrine after being unable to be weaned from intravenous vasopressors for more than 24 hours. Patients were categorized into two subgroups depending on the pattern of midodrine discontinuation (tapered dosing regimen vs. nontapered regimen). The primary endpoint was the incidence of inotropes and vasopressors re-initiation after midodrine discontinuation.

RESULTS

The incidence of inotropes or vasopressors' re-initiation after discontinuation of midodrine was lower in the tapering group (15.4%) compared with the non-tapering group (40.7%) in the crude analysis as well as regression analysis (odd ratio [OR] = 0.15; 95% CI = 0.03, 0.73, P = 0.02). The time required for the antihypertensive medication(s) initiation after midodrine discontinuation was longer in patients who had dose tapering (beta coefficient (95% CI): 3.11 (0.95, 5.28), P = 0.005). Moreover, inotrope or vasopressor requirement was lower 24 hours post midodrine initiation. In contrast, the two groups had no statistically significant differences in 30-day mortality, in-hospital mortality, or ICU length of stay.

CONCLUSION AND RELEVANCE

These real-life data showed that tapering midodrine dosage before discontinuation in critically ill patients during weaning from vasopressor aids in reducing the frequency of inotrope or vasopressor re-initiation. Application of such a strategy might be a reasonable approach among ICU patients unless contraindicated.

Exploring the Efficacy of Midodrine for Tapering Off Vasopressors

Sepsis and septic shock represent critical conditions, often necessitating vasopressor support in the intensive care unit (ICU). Midodrine, an oral vasopressor, has gathered attention as a potential adjunct to vasopressor therapy, aiming to facilitate weaning and improve clinical outcomes. However, the efficacy of midodrine remains questionable, with conflicting evidence from clinical trials and meta-analyses. This article provides a comprehensive review of the literature on midodrine's role in ICU settings by gathering evidence from multicenter trials, retrospective studies, and meta-analyses. While some studies suggest a limited benefit of midodrine in expediting vasopressor weaning and reducing ICU/hospital stays, others report potential advantages, particularly in reducing mortality rates among septic shock patients. Ongoing efforts aim to address knowledge gaps surrounding midodrine's efficacy and safety.

Droxidopa or Atomoxetine for Refractory Hypotension in Critically Ill Cardiothoracic Surgery Patients

OBJECTIVE

To evaluate the effects of droxidopa or atomoxetine on intravenous (IV) vasoactive agent discontinuation in cardiothoracic intensive care unit (ICU) patients with hypotension refractory to midodrine.

DESIGN

Single-center, retrospective cohort study.

SETTING

Tertiary- and quaternary-care university teaching hospital.

PARTICIPANTS

Included patients who received at least 4 consecutive doses of droxidopa or atomoxetine and remained on concurrent midodrine. Patients were excluded if they received study medication before admission, had clinical deterioration after study medication initiation requiring additional vasoactives/escalation of IV vasoactive dosage for at least 12 hours, had a diagnosis of hepatorenal syndrome, were prisoners, or were pregnant.

INTERVENTIONS

Droxidopa, atomoxetine, or both.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was time to discontinuation of IV vasoactive agents after initiation of study medication, analyzed using a Kaplan-Meier estimate with the Wilcoxon method, censoring death within 24 hours of the last dose of study medication. No adjustment for repetitive analyses was made, as the analysis was hypothesis-generating. Of the 72 charts reviewed, 45 patients met inclusion criteria (18 atomoxetine, 17 droxidopa, and 10 both). There were no differences in median time to discontinuation of IV vasoactive agents (21.9 days v 8.0 days v 13.9 days, respectively; p = 0.259) or ICU or hospital length of stay between groups. A higher percentage of patients who survived to hospital discharge received both study medications or droxidopa alone (90% v 76.5%) than atomoxetine alone (44.4%, p = 0.028).

CONCLUSIONS

Droxidopa and atomoxetine are oral vasoactive agents with potential mechanisms to facilitate IV vasopressor weaning for patients in the ICU with hypotension refractory to midodrine, but further prospective research is needed.

The Use of Midodrine as an Adjunctive Therapy to Liberate Patients from Intravenous Vasopressors: A Systematic Review and Meta-analysis of Randomized Controlled Studies

BACKGROUND

Studies evaluating the role of midodrine as an adjunctive therapy to liberate patients with shock from intravenous (IV) vasopressors have yielded mixed results. The aim of our study was to evaluate the efficacy and safety of midodrine as an adjunctive therapy to liberate patients with shock from IV vasopressors.

METHODS

Electronic searches of the MEDLINE, EMBASE, and Cochrane databases through April 2022 for randomized controlled trials (RCTs) that evaluated the use of midodrine versus control in patients with shock and a low dose of IV vasopressors. The primary outcome was total IV vasopressor time, while the secondary outcomes included time-to-IV vasopressor discontinuation, IV vasopressor restart, intensive care unit (ICU) length of stay (LOS), hospital LOS, and incidence of bradycardia.

RESULTS

The final analysis included four RCTs with a total of 314 patients: 158 in the midodrine group and 156 in the control group, with a weighted mean age of 64 years (54.2% men). There was no significant difference in the total IV vasopressor time between the midodrine and control groups (standardized mean difference [SMD] - 0.53; 95% confidence interval [CI] - 1.38 to 0.32, p = 0.22; I² = 92%). Also, there were no significant differences between the two groups in the time-to-IV vasopressor discontinuation (SMD - 0.05; 95% CI - 0.57 to 0.47, p = 0.09), IV vasopressor restart (19.3 vs. 28.3%; risk ratio [RR] 0.74; 95% 0.25-2.20, p = 0.59), ICU LOS (SMD - 0.49; 95% CI - 1.30 to 0.33, p = 0.24), and hospital LOS (SMD 0.01; 95% CI - 0.27 to 0.29, p = 0.92). However, compared with the control group, the midodrine group had a higher risk of bradycardia (15.3 vs. 2.1% RR 5.56; 95% CI 1.54-20.05, p = 0.01).

CONCLUSIONS

Among patients with vasopressor-dependent shock, midodrine was not associated with early liberation of vasopressor support or shorter ICU or hospital length of stay. Adding midodrine increased the risk of bradycardia. Further large RCTs are needed to better evaluate the efficacy and safety of midodrine in liberating patients from IV vasopressors.

Midodrine use in critically ill patients: a narrative review

Midodrine is a peripherally acting, oral α-agonist that is increasingly used in intensive care units despite conflicting evidence for its effectiveness. It has pharmacological effects on blood vessels as well as pupillary, cardiac, renal, gastrointestinal, genitourinary, lymphatic and skin tissue. It has approval for use as a treatment for orthostatic hypotension, but a surge in interest over the past decade has prompted its use for a growing number of off-label indications. In critically ill patients, midodrine has been used as either an adjunctive oral therapy to wean vasoplegic patients off low dose intravenous vasopressor infusions, or as an oral vasopressor agent to prevent or minimise the need for intravenous infusion. Clinical trials have mostly focused on midodrine as an intravenous vasopressor weaning agent. Early retrospective studies supported its use for this indication, but more recent randomised controlled trials have largely refuted this practice. Key questions remain on its role in managing critically ill patients before intensive care admission, during intensive care stay, and following discharge. This narrative review presents a comprehensive overview of midodrine use for the critical care physician and highlights why lingering questions around ideal patient selection, dosing, timing of initiation, and efficacy of midodrine for critically ill patients remain unanswered.

Midodrine therapy for vasopressor dependent shock in the intensive care unit: a protocol for a systematic review and meta-analysis

INTRODUCTION

Intensive care unit (ICU) lengths of stay are modified by ongoing need for haemodynamic support in critically ill patients. This is most commonly provided by intravenous vasopressor therapy. Midodrine has been used as an oral agent for haemodynamic support in patients with orthostatic hypotension or cirrhosis. However, its efficacy in treating shock in the ICU, particularly for patients weaning from intravenous vasopressors, remains uncertain. The objective of this systematic review is to determine the efficacy of midodrine in vasopressor dependent shock.

METHODS AND ANALYSIS

We will search Ovid MEDLINE, Ovid Embase, CINAHL and Cochrane Library for observational trials and randomised controlled trials evaluating midodrine in critically ill patients from inception to 21 April 2022. We will also review unpublished data and relevant conference abstracts. Outcomes will include ICU length of stay, duration of intravenous vasopressor support, ICU mortality, hospital mortality, hospital length of stay and rates of ICU readmission. Data will be analysed in aggregate, where appropriate. We will evaluate risk of bias using the modified Cochrane tool and certainty of evidence using Grading of Recommendations, Assessment, Development and Evaluations methodology. We will perform trial sequential analysis for the outcome of ICU length of stay.

ETHICS AND DISSEMINATION

Ethics approval is not required as primary data will not be collected. Findings of this review will be disseminated through peer-related publication and will inform future clinical trials.

PROSPERO REGISTRATION NUMBER

CRD42021260375.

Contemporary hemodynamic management of acute spinal cord injuries with intravenous and enteral vasoactive agents: A narrative review

DISCLAIMER

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

The pathophysiology and hemodynamic management of acute spinal cord injuries, including the use of intravenous and enteral vasoactive agents, are reviewed.

SUMMARY

Spinal cord injuries are devastating neurological insults that in the acute setting lead to significant hemodynamic disturbances, including hypotension and bradycardia, that are influenced by the level of injury. High thoracic (usually defined as at or above T6) and cervical injuries often manifest with hypotension and bradycardia due to destruction of sympathetic nervous system activity and unopposed vagal stimulation to the myocardium, whereas lower thoracic injuries tend to result in hypotension alone due to venous pooling. Initial management includes maintaining euvolemia with crystalloids and maintaining or augmenting mean arterial pressure with the use of intravenous vasoactive agents to improve neurological outcomes. Choice of vasopressor should be based on patient-specific factors, particularly level of injury and presenting hemodynamics. This review includes the most recent literature on intravenous vasopressors as well as the limited evidence supporting the use of enteral vasoactive agents. Enteral vasoactive agents may be considered, when clinically appropriate, as a strategy to wean patients off of intravenous agents and facilitate transfer outside of the intensive care unit.

CONCLUSION

The hemodynamic management of acute spinal cord injuries often requires the use of vasoactive agents to meet mean arterial pressure goals and improve neurological outcomes. Patient-specific factors must be considered when choosing intravenous and enteral vasoactive agents.

Midodrine to optimize heart failure therapy in patients with concurrent hypotension

According to the Centers for Disease Control and Prevention statistics, about 6.2 million adults in the United States have heart failure. Guideline-Directed Medical Therapy (GDMT) involving the use of renin-angiotensin-aldosterone system inhibitors with or without a neprilysin inhibitor, β-blockers, mineralocorticoid-receptor-antagonists, and sodium-glucose cotransporter-2 inhibitors serve as the backbone for heart failure with reduced ejection fraction (HFrEF) therapy. However, in patients with refractory hypotension, the initiation of GDMT may not be possible. We present four cases where the use of midodrine, an alpha adrenergic agonist, serves as bridge therapy for the initiation or continuation of GDMT with marked clinical improvement. These cases illustrate how exacerbations of HFrEF may be ameliorated with outpatient midodrine titration among patients with baseline, persistent hypotension such that GDMT may be better tolerated.