Prolonged QT Interval due to Medication

Aka: Prolonged QT Interval due to Medication, Drug-Induced Torsades de Pointes

1. See Also
   1. Prolonged QT
   2. Torsades de Pointes
2. Risk Factors: Medication-Induced Torsades de Pointes
   1. Female gender
   2. Hypokalemia
   3. Severe Hypomagnesemia
   4. Bradycardia
   5. Atrial Fibrillation Cardioversion recently
   6. Congestive Heart Failure
   7. Concurrent Digoxin use
   8. Baseline QT Prolongation or subclinical Long QT
3. Causes: Medications causing Torsades de Pointes
   1. General
      1. Higher doses of predisposing drug raise risk
      2. Rapid drug administration raises risk
   2. Overall associated medication classes causing Prolonged QT interval
      1. Amphetamines
      2. Anticholinergics
      3. Antihistamines (e.g. Diphenhydramine)
      4. Anti-emetics
         1. Ondansetron (Zofran)
         2. Dolasetron (Anzemet)
         3. Granisetron
         4. Consider lower risk agents: Palonosetron (Aloxi), Prochlorperazine, or metoclopramide (Reglan) instead
      5. Decongestants
      6. Diuretics
      7. Fluoroquinolones
         1. Class effect
         2. Consider lower risk agent: Ciprofloxacin
      8. Macrolides
         1. Highest risk: Clarithromycin, Erythromycin
         2. Consider Zithromax as a lower risk agent if Macrolide needed
      9. Opioids
         1. Highest risk agents: Methadone, Buprenorphine, Oxycodone
         2. Consider lower risk agents: Morphine
      10. Phenothiazines
      11. Protease Inhibitors
      12. Antipsychotics
          1. Highest risk: Thioridazine, pimozide, Haloperidol, chlorperazine
          2. Some risk: Geodon, Fanapt, Inega, Saphris, Seroquel
          3. Consider lower risk agents: Abilify, Latuda, Zyprexa
      13. Antidepressants
          1. Highest risk
             1. Tricyclic Antidepressants
             2. Trazodone
             3. Citalopram (especially in combination with Cytochrome P450 2C19)
          2. Some risk: Venlafaxine, SSRIs in general
          3. Consider lower risk agents: Bupropion, Duloxetine, Mirtazapine
      14. Sympathomimetics
      15. Vasodilators
   3. Medications that more commonly cause Torsades
      1. Bepridil
      2. Disopyramide
      3. Dofetilide
      4. Ibutilide
      5. Procainamide
      6. Quinidine
      7. Sotalol
   4. Medications that less frequently cause Torsades
      1. Amiodarone
      2. Arsenic trioxide
      3. Chlorpromazine
      4. Cisapride
      5. Clarithromycin
      6. Domperidone
      7. Droperidol
      8. Erythromycin
      9. Halofantrine
      10. Haloperidol
      11. Lidoflazine
      12. Mesoridazine
      13. Methadone
      14. Pentamidine
      15. Pimozide
      16. Sparfloxacin
      17. Thioridazine
4. References
   1. Roden (2004) N Engl J Med 350:1013-22
   2. Wexler (2011) Am Fam Physician 84(1): 63-9