Midazolam is a common medication doctors use to help patients relax before surgery or medical procedures.
It works by calming the brain and helping people feel sleepy and less anxious. Many patients who take it do not remember much of the procedure afterward, which can be a good thing for reducing fear and discomfort.
However, recent research from the University of Colorado Anschutz Medical Campus suggests that this medicine may not always be safe, especially when given at certain times of the day.
The researchers studied more than 1.7 million medical records from patients who had received midazolam during different kinds of procedures. Among these records, they found over 16,000 cases where patients experienced some form of heart damage.
When the team looked more closely at the data, they discovered something surprising. Patients who had their surgeries at night had a higher risk of heart injury than those who were treated during the day. Even more surprising, the risk was highest in people who were otherwise healthy and had no previous heart problems.
This led scientists to wonder why the time of day could change how the drug affects the heart. To understand this, they turned to one of the body’s most important systems—the circadian rhythm.
Circadian rhythms are the body’s natural 24-hour cycles that control when we sleep, wake, eat, and perform many other biological functions. These rhythms also help protect organs like the heart. At night, for example, our heart rate and blood pressure naturally drop to help the body rest and recover.
The researchers found that a gene called PER2 plays a key role in protecting the heart. This gene is part of the circadian system and helps the heart cells stay healthy and strong. They then explored how midazolam interacts with this gene, both in human data and in animal studies using mice.
What they discovered was that midazolam increases the level of a brain chemical called GABA, which has a calming effect. This is what helps patients feel relaxed and less anxious. But at night, this same effect reduces the activity of the PER2 gene, making the heart more vulnerable to damage.
This finding shows that timing really matters when giving certain medicines. A drug that is safe in the daytime may not act the same way at night because of changes in the body’s internal clock.
The researchers suggest that doctors should pay more attention to when medications are given, not just which drug or how much. This idea is part of what scientists call “personalized medicine,” which means tailoring treatment to each patient’s unique needs—including the best time of day for it to work safely.
In fact, doctors already know that some medications, such as blood pressure pills, work better when taken at night. Extending this approach to other drugs could make treatments more effective and safer. If hospitals and clinics begin to align drug schedules with patients’ natural rhythms, they might be able to prevent side effects and improve recovery outcomes.
The study, led by Dr. Tobias Eckle and published in the journal *Frontiers in Cardiovascular Medicine*, encourages healthcare providers to rethink how they use time as a factor in treatment. It also opens up a new area of research called “chronotherapy,” which studies how the time of day affects how the body responds to drugs.
This research serves as a reminder that our bodies are deeply connected to the natural day-and-night cycle. When medical treatments respect that rhythm, they may protect the heart and other organs more effectively. In the future, understanding and applying these timing principles could lead to safer surgeries, better recovery rates, and improved overall health.
If you care about heart health, please read studies that yogurt may help lower the death risks in heart disease, and coconut sugar could help reduce artery stiffness.
For more information about health, please see recent studies that Vitamin D deficiency can increase heart disease risk, and results showing vitamin B6 linked to lower death risk in heart disease.
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