Friday October 31, 2008

Q; While on "Rapid response team", you have been called to drug rehab. unit to evaluate a 34 year old female who found hypotensive and dizzy. Nurses confirmed that under strict watch, no narcotic has been taken by patient. As you hook the monitor, it shows frequent runs of Torsades De Pointes. Review of medicine list shows patient under treatment with methadone and 3 days ago started on Levofloxacin for suspected UTI?

Answer: Methadone induced QT prolongation, converted into Torsades due to Levaquin interaction.

Methadone is a long-acting narcotic pain medication commonly used in the treatment of narcotics addiction. Methadone causes prolongation of the QT interval and explains the development of Torsades De Pointes. Methadone causes dose-related increases in the QTC interval. Drugs taken by methadone patients may precipitate dangerous drug interactions when used with methadone, including prolongation of the QT interval.


Related Article: A Twist on Torsade: A Prolonged QT Interval on Methadone (J Gen Intern Med. 2006 November; 21(11): C9–C12)