Is Midazolam (Versed) or Lorazepam (Ativan) better for patients with prolonged QT interval?

From the Guidelines

For patients with prolonged QT interval, Ativan (lorazepam) is generally preferred over Versed (midazolam) due to its minimal effects on cardiac conduction and lower risk of further QT interval prolongation. When considering sedation options for patients with prolonged QT intervals, it is crucial to prioritize medications with the least potential to exacerbate this condition, thereby reducing the risk of torsades de pointes and other severe cardiac arrhythmias. The choice between Ativan and Versed should be guided by their pharmacological profiles and potential impacts on cardiac function. Ativan has a more favorable profile in this context because it does not significantly affect the QT interval, unlike some other benzodiazepines which may have more pronounced effects on cardiac conduction 1. Key considerations in the administration of these medications include:

• Starting with the lowest effective dose to minimize potential side effects
• Continuous cardiac monitoring to promptly identify any adverse effects on cardiac conduction
• Adjusting doses based on patient response and tolerability, especially in vulnerable populations such as the elderly or those with hepatic impairment
• Being aware of potential drug interactions that could further prolong the QT interval or exacerbate respiratory depression, a known side effect of benzodiazepines. Given the information available and focusing on minimizing morbidity, mortality, and improving quality of life, Ativan emerges as the preferable option for sedation in patients with prolonged QT intervals, provided that its use is carefully managed and monitored.

From the Research

Comparison of Versed and Ativan for Prolonged QT

• There are no direct studies comparing Versed (midazolam) and Ativan (lorazepam) for prolonged QT interval in the provided evidence.
• However, studies have investigated the effects of midazolam on the QT interval:
  • A study from 1995 2 found that midazolam followed by administration of either vecuronium or atracurium did not produce any significant change in QTc interval.
  • Another study from 1996 3 found that midazolam had no significant effect on QTc interval.
• Ativan (lorazepam) is not mentioned in the provided studies as being associated with QT interval prolongation.
• A study from 2021 4 provides general guidance on managing drug-induced QT prolongation, but does not specifically compare Versed and Ativan.
• A study from 2011 5 discusses the management of sedation in patients with prolonged QT syndrome, but does not compare Versed and Ativan.
• A study from 2010 6 explains the mechanisms of drug-induced QT interval prolongation, but does not specifically discuss Versed or Ativan.