Recent reports suggest that methadone may prolong the QTc interval and cause
torsades de pointes. This study was conducted to evaluate the prevalence of
QTc prolongation during oral methadone therapy and identify factors associated
with prolongation. Patients receiving oral methadone as treatment for chronic
pain or addiction were eligible for the study. One hundred four patients who
were receiving >/= 20 mg methadone per day for >/= 2 weeks underwent electrocardiograms
to measure QTc interval duration. Sixty-three (61%) patients were male and 63
(61%) were receiving methadone maintenance for opioid addiction. The mean (+/-
SD) age was 45.3 +/- 9.4 years. The median (range) methadone dose was 110 mg/day
(20-1200 mg/day); median (range) number of months on methadone was 12.5 months
(1-444 months). The median (range) QTc interval was 428 msec (396-494 msec).
Thirty-three percent had QTc prolongation (males 40%, females 20%; P=0.03).
No patient had a QTc longer than 500 msec. Significant dose response was observed
in males on methadone <12 months (rho=0.60, P=0.02). Our study suggests that
methadone may prolong the QTc interval in specific subpopulations but poses
little risk of serious prolongation.
Cruciani RA, Sekine R, Homel P, Lussier D, Yap Y, Suzuki Y, Schweitzer
P, Yancovitz SR, Lapin JA, Shaiova L, Sheu RG, Portenoy RK. J Pain Symptom Manage.
2005 Apr;29(4):385-91.
PMID: 15857742 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15857742
Credit: All abstracts retrieved from PubMed, developed by the National Center for
Biotechnology Information (NCBI) at the
National Library of Medicine (NLM).
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