Hemodynamic Effects of an Increased Midodrine Dosing Frequency

Area of Science:

• Critical Care Medicine
• Pharmacology

Background:

• Midodrine is used to reduce intravenous vasopressor requirements and intensive care unit (ICU) length of stay.
• Previous studies using midodrine every 8 hours have not shown clinical success.
• Suboptimal pharmacokinetics may explain the lack of efficacy at less frequent dosing intervals.

Purpose of the Study:

• To evaluate the institutional experience with midodrine administered every 6 hours.
• To assess the impact of a more frequent midodrine dosing schedule on vasopressor requirements.

Main Methods:

• Retrospective, descriptive study conducted at a single academic medical center.
• Included adult patients receiving midodrine every 6 hours or four times daily.
• Data were abstracted from electronic medical records without intervention.

Main Results:

• Forty-four patients were included, with an average age of 65 years.
• Over half of the patients (52.3%) were on IV vasopressors when midodrine was initiated every 6 hours.
• Vasopressor requirements decreased by 50% (0.10 to 0.05 norepinephrine equivalents) within 24 hours of implementing the every 6-hour midodrine regimen.

Conclusions:

• Administering midodrine every 6 hours may optimize its pharmacokinetic profile.
• This dosing frequency appears safe and potentially enhances efficacy.
• Prospective evaluation of midodrine every 6 hours is warranted as a strategy for accelerated IV vasopressor weaning.