Posted by Sunnely on June 6, 2001, at 23:59:13
In reply to Bad Interactions with Buspar/Celexa?, posted by Nathan on June 6, 2001, at 22:48:29
Hi Nathan,
Granted your experienced serotonin syndrome, it is possible that it was induced by the combination of Celexa/Serzone/Buspar. All have serotonergic effect and the type of drug-drug interaction probably involved both "pharmacodynamic" (increased stimulation of the serotonin receptors) and "pharmacokinetic" probably via the cytochrome enzymes. Both Celexa and Serzone have serotonin reuptake inhibiting effect, while BuSpar is a serotonin (5HT1A) agonist. Increased supply of serotonin due to this "pharmacodynamic" drug interaction could lead to excessive stimulation of serotonin receptors and the subsequent occurrence of serotonin syndrome.
Serzone is a marked inhibitor of the cytochrome enzyme CYP3A4. BuSpar is heavily dependent on CYP3A4 for its metabolism while Celexa partly depends on this enzyme for its metabolism. (Celexa is also metabolized by CYP2C19). With the addition of Serzone, the blood levels of BuSpar and Celexa increased several times leading to increased side effects including the occurrence of serotonin syndrome. This is the "pharmacokinetic" drug interaction involving these drugs.
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> I have been taking Buspar and Zoloft for about 3 years. I stopped the Zoloft about a month ago (by tapering). I have since tried Celexa (only 5 mg) and today I tried Serzone (50 mg). When I took the Celexa I experienced very negative side effects that I chalked up to the drug. The side effects were similar to serotonin syndrome -- I felt very hot, confused, numb, disoriented and out-of-body. I decided Celexa was not for me. Today I took Serzone (50 mg) and I had the same experience. Could the combination of Buspar and Celexa/Serzone be causing effects consistant with too much serotonin? I encountered no problems with the Buspar/Zoloft combo. I decided to go off the Zoloft because I felt it made me too complacent and it killed my sex drive. Interestingly, since I stopped Zoloft I have had zero sex drive which is worse than when I was taking Zoloft. Does anybody have any suggestions? Thanks for your help.
poster:Sunnely
thread:65610
URL: http://www.dr-bob.org/babble/20010605/msgs/65620.html