methadone induced arrhythmia; fact or myth should we add regular ekg monitoring to mmt protocol?

methadone is a synthetic opioid used as the standard treatment for narcotics dependence.cyp3a is the major enzyme to metabolize methadone. long qt syndrome and secondary tdp (a polymorphic ventricular tachycardia) to methadone is generally rare, but in the past few years, gained attention of many scientists as a potentially fatal complications caused by methadone. interact  with voltage-dependent potassium channels prolong the action potential and qt. qtc of 430-450 ms in females and 450-430 ms in males is considered prolonged. some studies consider qtc shorter than 450 ms as normal and qtc longer than 450 ms as prolonged. prolonged qtc leading to tdp is reported 470-615 ms in different studies. we will discuss more details regarding considering qtc syndrome during mmt, in the current article.