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Sean Cate
Sean Cate
December 21, 2023 ·  2 min read

Common Sedative May Cause Heart Damage When Taken at Night

A common sedative used before surgery, Midazolam, could be responsible for some unexpected risks if administered at night. Recent findings from a University of Colorado study (Anschutz Medical Campus) shed light on some concerning connections between Midazolam and potential heart injuries, particularly during nighttime surgeries.

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What is Chronotherapy?

Chronotherapy, the practice of applying treatments based on the body’s natural sleep-wake (or circadian) rhythms, emerges as a crucial aspect of knowing the risks associated with Midazolam administration. The research linking Midazolam’s timing with heart injury during surgeries, especially at night, underscores the significance of chronotherapy in medical practice.

Chronotherapy offers a new dimension in medicine by emphasizing the critical role timing plays in the efficacy and safety of treatments. Understanding how drugs interact differently with the body depending on the administration time could pave the way for more personalized and safer medical practices, particularly in surgical settings where timing could significantly impact patient outcomes.

The study, published in Frontiers in Cardiovascular Medicine, analyzed data from over 950,000 surgeries involving Midazolam. While Midazolam itself didn’t significantly increase the overall risk of heart injury, the timing of its administration played a crucial role.

Midazolam’s Effect on the Heart


Studies indicated that Midazolam might interfere with a protective heart protein, PER2, especially when given at night.2 This sedative alters the GABA neurotransmitter, regulating PER2 levels. PER2 is crucial for heart function when administered at night. This sedative’s interaction with the GABA neurotransmitter lowers PER2 levels during nighttime doses, potentially increasing the heart’s vulnerability to injury.

Although Midazolam usage overall didn’t show a substantial risk increase, the timing of its administration, especially at night or among healthier patients, correlated with a heightened risk of myocardial injury. This raises crucial concerns about the timing of sedative administration before surgeries.

The Nighttime Risks

The research revealed a strong association between Midazolam use and an increased risk of myocardial injury during nighttime procedures or among healthier patients. This significant link between sedative timing and potential heart complications warrants a reevaluation of medical protocols concerning sedative administration. Knowing this link between Midazolam, the timing of its application, and potential heart injury opens a critical dialogue in the medical community. Rethinking the timing of sedative administration, especially during nighttime surgeries, is vital for patient safety. Not only that, but we should strive to find out why.

Sedative Timing Matters

Midazolam, a widely used sedative before surgery, demonstrates a potential risk of heart damage, particularly when administered at night, as per how the PER2 heart protein and GABA neurotransmitters. These findings urge a reconsideration of the timing for administering sedatives like Midazolam before surgeries. Understanding the nuances of timing in drug administration is crucial for enhancing patient safety and care.

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  1. Night-Time Use of Sedative Increases Heart Damage Risk.” Technology Networks. Katie Brighton. February 4, 2023.
  2. Time-of-day dependent effects of midazolam administration on myocardial injury in non-cardiac surgery.” Frontiers. Meghan Prin, et al. October 28, 2022.
  3. Common Surgery Sedative Can Increase Risk of Heart Damage When Used at Nigh.” CU Anschutz. David Kelly. November 1, 2022.