Seroquel and Methadone

Attached a link to an article published in the New York Times (July 19th, 2011) http://www.nytimes.com/2011/07/19/health/19drug.html reporting that at the request of the Food and Drug Administration, AstraZeneca is adding a new heart warning to the labels of Seroquel, its blockbuster antipsychotic.
The revised label emphasizes that drug.Seroquel and extended-release Seroquel XR “should be avoided” in combination with at least 12 other medicines linked to a heart arrhythmia that can cause sudden cardiac arrest.The previous Seroquel labels had mentioned the risk of a prolonged QT interval, but had not identified other drugs to avoid, Stephanie Andrzejewski, a spokeswoman for AstraZeneca, said Monday. The new warning also is separated from other warnings and precautions on the label, she said, “to provide some additional guidance to physicians” treating patients ”who are already at risk of QT prolongation.”
The new label lists the other drugs to avoid as antiarrhythmic drugs like quinidine, procainamide, amiodarone and sotalel; antipsychotic drugs like ziprasidone, chlorpromazine and thioridazine; antibiotics like gatifloxacin and moxifloxacin; the anti-infective drug pentamidine; and synthetic opioids like levomethadyl acetate and methadone. The label also raises caution about use by the aged and people with heart disease. As addiction professionals we should know that Seroquel has a potentially deadly interaction with methadone in regard to the QT interval, even though the FDA is downplaying this risk!
Methadone use and deaths have increased drastically in recent years as more doctors prescribe it for chronic pain. The number of methadone prescriptions for pain in the United States rose to 4.3 million in 2010 from 2.2 million in 2006, IMS Health, an industry data firm, said Monday. The use for pain has surpassed that for heroin withdrawal and maintenance.

Yours
Bernd