Lamictal (Lamotrigine) level when taken with Tegretol XR

[forward2007]

I had my Tegretol XR and Lamotrigine levels tested on 05-20-10. At the time I was taking 1200 mg/day of Tegretol XR and 400 mg/day of Lamotrigine. My Tegretol XR was at 7.4 ((Theraputic range 4.0-8.0) and my Lamotrigine level was at 2.7 (Theraputic range 2.0-20.0). At 2.7 is the Lamotrigine even helping at all? I had recently tried to lower my Tegretol XR doese from 1200 mg/day to 800 mg/day but started having seizures I wasn't having before so I raised it back up to 1200 mg/day. I also recently raised the Lamotrigine dose to 500 mg/day. I was told it is now accepted to take up to 500 mg/day of Lamotrigine when being taken with Tegretol. I am going to get both my Tegretol XR and Lamotrigine levels tested again soon. Has anyone else here had their Lamotrigine level tested when they were taking it with another AED? If so, what level was it at?

 

[Nakamova]

You might want to check this out: http://www.drugs.com/drug-interactions/lamictal-with-tegretol-1430-848-497-234.html

The gist is that Tegretol can reduce the blood serum level of the Lamictal by as much as 40%. And Lamictal can potentially make Tegretol more toxic. This means you need to be careful when messing with the doses of either med.

It also says that when Lamictal is added as an adjunct, the maintenance dose is in the 300-500mg/day range.

Also, don't know if this is helpful/relevant, but I'm on Lamictal monotherapy, at 175mg/day. My most recent blood serum level was 4.0.