Medications with Potential to Prolong QT Interval
Several medications, including methadone, have the potential to prolong the QT interval.
PharmaNet should be reviewed for drugs that may potentially cause a prolonged QT interval prior to initiating or refilling a methadone prescription. Commonly prescribed drugs that may prolong the QT interval are included in the table below. In addition, Credible Meds provides a list of QT-prolonging drugs, and an overview of prolonged QT intervals and Torsades de Pointes.
When possible, avoid prescribing multiple QT prolonging medications simultaneously, especially in patients that have other risk factors. If a prolonged QTc is found or there are questions about safely prescribing multiple QT-prolonging medications simultaneously, prescribers are encouraged to consult the 24/7 Line or the RACE app.
Commonly Used Drugs That May Cause Prolonged QT Intervals
Drug Class | Examples |
Antiarrhythmics- Class I and III antiarrhythmics |
Amiodarone Sotalol Quinidine Procainamide Dofetilide Ibutilide |
Antimicrobial agents- Fluoroquinolones, Macrolides, Antifungal agents |
Ciprofloxacin Moxifloxacin Levofloxacin Erythromycin Ketoconazole Itraconazole |
Antipsychotic agents | Haloperidol Thioridazine Quetiapine Droperidol Ziprasidone Risperidone Clozapine |
Antidepressants | Amitriptyline Desipramine Imipramine Doxepin Fluoxetine Sertraline Venlafaxine |
Antivirals | Nelfinavir |
Antimalarials | Chloroquine Mefloquine |
Opioid analgesic/opioid agonist | Methadone |
Other | Cisapride Sumatriptan Zolmitriptan Arsenic Dolasetron Tacrolimus |