Zyvox antibiotic and antidepressants may be fatal combination

Zyvox and antidepressants may be fatal combination July 27, 2011 - 2:36PM

http://www.smh.com.au/lifestyle/wellbeing/zyvox-and-antidepressants-may-be-fatal-combination-20110727-1hznv.html

Pfizer's Zyvox antibiotic can cause potentially fatal central nervous system reactions in patients who also take antidepressants that increase levels of the brain chemical serotonin, US regulators said.



Pfizer's Zoloft and Pristiq, Eli Lilly's Cymbalta and GlaxoSmithKline's Paxil and Wellbutrin are among 29 psychiatric drugs that patients may need to stop taking temporarily when they require treatment with Zyvox, the Food and Drug Administration said in a drug safety communication.



Zyvox can interact with these antidepressants to cause a toxic reaction known as serotonin syndrome, in which excess amounts of the chemical build up in the brain, according to the FDA.



Some deaths among patients who suffered such a reaction were reported to the FDA's adverse-event database, the agency said.



Pfizer reported $1.18 billion in revenue from Zyvox last year.



Confusion, memory issues, hyperactivity, excessive sweating and muscle twitching are among the symptoms of excess serotonin levels.



Patients taking psychiatric drugs should not stop using them without first consulting a health-care professional, the FDA said.

The current US package insert for Zyvox "already includes prominent information regarding the potential for serotonergic interactions, the risk of serotonin syndrome and the need for careful observation of patients prescribed Zyvox who are on such agents", Kristen Neese, a Pfizer spokeswoman, said.



The company has not identified any new safety signals related to those drug interactions, she said.



"In an ongoing commitment to ensure patient safety, Pfizer continually monitors all relevant safety information including information pertaining to the concomitant use of Zyvox and serotonergic antidepressant medications," Neese said.



Bloomberg









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