Posted by Cam W. on July 25, 2000, at 7:13:19
In reply to Re: CAM, need some info desperately, posted by Sunnely on July 25, 2000, at 1:00:50
Sunnely - A slow taper on of Tegretol and desipramine with a slow taper off of Prozac should be no problem in a compliant person. You are correct that the Prozac and Tegretol can alter each other's metabolism; sometimes in unpredictable ways, but I have also seen both used together several times, with no ill effects. Though these drugs interact, it shouldn't preclude one from using them together; with a caveat. Like you said, this combination (Prozac + desipramine + Tegretol) should be monitored for adverse effects and blood levels should also be monitored for Tegretol and desipramine. This close monitoring (in this case) should be done in 2 stages. Initially for 5 weeks until the Prozac clears the system significantly and then in about 8-10 weeks, when Tegretol seems to begin to induce it's own metabolism (and it's dose usually needs to be raised). Serotonin syndrome should not be a problem, as desipramine is mainly noradrenergic in action.
The CYP-3A4 inducing effects of Tegretol really do not affect desipramine, but it can affect the hydroxylation of imipramine to desipramine. CYP-2D6 is still the major enzyme system in both the metabolism of imipramine and desipramine, which does not metabolize Prozac. Since desipramine is being used (and not imipramine) the Tegretol/desipramine should really not interact.
Desipramine can be a problem in slow metabolizers of CYP-2D6, but this can occur in the absence of other drugs. Therefore, the side effects of desipramine (and TCAs in general) that you mention, must be closely watched in the first couple of weeks especially.
After rereading my last post, I do realize I was a little complacent in the way I shrugged off the interactions. I just see many drugs that interact in a potentially serious manner used in combination by some aggressive pdocs (even Prozac and TCAs, quite commonly) in treatment refractory patients.
I cannot believe that Greg's doc would start him on desipramine and Tegretol without considering the taper of Prozac. Both doses of desipramine and Tregretol should be started at normally sub-therapeutic doses and increased gradually as the Prozac is eliminated from the body. Done correctly, there should really be no antidepressant off-time with this method.
Thanks Sunnely, I appreciate your imput and caution against my blaise attitude. Sometimes I do get jaded with some of the combinations that I see.
Keep me honest - Cam
poster:Cam W.
thread:41333
URL: http://www.dr-bob.org/babble/20000717/msgs/41365.html