Have you considered taking Magnesium? It helps muscles relax. It also is an anticonvulsant. My daughter takes 1000 mg per her neurologist.
However when she was taking meds, Lamictal made her muscles and bones ache. So it could be a side effect.
I would look into the side effects of each and also how they interact with each other.
I am taking effexor XR, 75 mg, once daily. Other than that, I take a multi-vitamin, extra vit-c, citri-cal calcium, vit-b, omegas, glucosamine and condritin, and an herbal remedy for ovairian cysts called DonQui. I sometimes also take white willow bark for pain, either in capsul form or as a hot tea beverage.
What medicines are you taking?