I did a web search on kava kava and come up with two interesting pieces of info:

1) risk of serious liver damage: kava kava effects the liver enzymes in such a way that the potency of both it and other drugs already in the body are elevated. While not a lot of tests have been done, one must presume that it will interact with any drug.

2) it has an effect on the central nervous system and it expressly warns for those with Parkinsons.

So while nothing on MG specifically, it may not be a good idea. And if you decide to use it, I would make sure hubby knows and is watching you closely for any negative impact.