Q:  Depakote/Lamotrigine Interaction

I am confused about your information re: depacote/lamictal interation on the psych.education.org site.

Part of the paragraph from lamotrigine link reads:
...because Depakote can double lamotrigine levels and itself be increased 30% by the lamotrigine; however, then can be used together, one must just be careful with the combination). 

I thought lamictal decreases the efficacy of depacote/and perhaps lowers depacote levels? Perhaps I'm mistaken.

I appreciate your clarification.

Thanks.


Hello Ms. B' --
Well, looks like we're both right in terms of finding statements both ways.  Most sites I just surfed through talk about lamotrigine decreasing Depakote levels; whereas material by Dr. Lori Altshuler, a UCLA expert, states that lamotrigine increases Depakote levels (you have to sift in here, but you'll find it, if you want to check that reference). 

However, there's a better way than just surfing for references, theoretically, and that's to look at what lamotrigine does to enzymes that metabolize Depakote.  If it lowers them, or their activity, then the medication should increase Depakote levels, and vice versa.  

By that logic, Depakote is listed on one table I consulted as metabolized by the liver enzyme known as CYP - 2C.  Unfortunately I can't find lamotrigine on these lists (they aren't new enough).  If you would like to do some snooping and send me the lamotrigine effects on CYP-2C, that would move things along!  

Thanks for writing. 

Dr. Phelps