Q: Combining which 2 epileptic drugs may increase the risk of  Stevens–Johnson syndrome?

Answer:  lamotrigine (lamictal) with sodium valproate (Depakote)

Stevens-Johnson syndrome is a rare but life-threatening acute mucocutaneous hypersensitivity reaction, well known during treatment with antiepileptic drugs (AEDs).

Kocak S, Girisgin SA, Gul M, Cander B, Kaya H, Kaya E. - Stevens-Johnson syndrome due to concomitant use of lamotrigine and valproic acid.  Am J Clin Dermatol. 2007;8(2):107-11.