Does Clonazepam increase the risk of QT prolongation?

Question

Hello doctor,

I have been suffering from panic attacks and anxiety for several years, and on top of that, essential tremor affects my everyday life. A couple of weeks ago, my doctor prescribed Clonazepam for me, but after doing some research online, I have a few concerns. Does Clonazepam increase the risk of QT prolongation or other serious heart problems? I am particularly cautious because I have been experiencing PVCs (premature ventricular contractions) daily for over a year.

Occasionally, I also experience bradycardia and, every now and then, short bursts of an accelerated heartbeat accompanied by a fluttering sensation. These symptoms are still under investigation. I have had several ECGs, and on one of them, my QT and QTc were recorded as 412 ms and 447 ms, respectively, at a heart rate of 71 bpm. I am concerned about the possibility of Clonazepam making my QT interval longer.

I have also used Oxazepam in the past. Is it a safer option regarding the risk of QT prolongation, or can I safely continue taking Clonazepam?

Please advise.

Answer 1

Hello,

Welcome to icliniq.com.

Long-term use of Clonazepam, as well as high doses, can increase the risk of developing acquired long QT syndrome. That said, a QTc of 447 ms is within the acceptable limit for women, which is less than 460 ms. Oxazepam is considered a safer option, but if you combine either medication with another QT-prolonging drug, the QT interval may become dangerously prolonged. Additionally, it is important to avoid low potassium levels and the use of diuretics (medications that promote urination), as these can further increase the risk.

Your description of PVCs (premature ventricular contractions) suggests that a Holter monitor and ECG might be helpful to rule out any pause-dependent arrhythmias. An echocardiogram is also recommended to rule out structural heart disease.

I hope this helps you.

Thank you.