Posted by Scott L. Schofield on March 12, 2000, at 17:15:29
In reply to Re: Reboxetine lamictal, posted by JohnL on March 12, 2000, at 14:12:58
I am about to add reboxetine 4 mg/day to an ongoing treatment with Lamictal (lamotrigine) 300 mg/day. After reading JohnL's post, I thought it best to do some snooping on Medline to see if there were any investigations studying the kinetic interactions between the two. I could not find any. The best that I could come up with using separate searches is that there doesn't seem to be any metabolic pathways that the two have in common. Lamictal is metabolized via glucuronidation, the same pathway as is Depakote. This accounts for the interaction between these two drugs. Reboxetine is metabolized primarily by cytochrome P450 3A4. I could find no references regarding reboxetine and glucuronidation.
At this point, I feel comfortable adding reboxetine to the Lamictal. I have already established for myself which clinical side effects appear when I take more than 300 mg/day of Lamictal monotherapeutically or in combination with MAO inhibitors and tricyclics. I should be able to tell if blood levels increase. More importantly, having taken Lamictal at clinically relevent dosages for some time, I doubt there is much risk of developing the rash-reaction, which usually occurs at the beginning. This would not be true when adding Lamictal to ongoing reboxetine therapy or when starting both at the same time. I guess the conservative approach would be to take JohnL's recommendation, and begin Lamictal as if you were also taking Depakote. You may want to take a look at the schedule suggested by the PDR.
Be wary that the induction of mania should always be considered a possibility when using any antidepressant for treating bipolar disorder. Although Lamictal is now being used as a mood-stabilizer, it does not always prevent this from happening.
- Scott
poster:Scott L. Schofield
thread:26758
URL: http://www.dr-bob.org/babble/20000312/msgs/26778.html