This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Concomitant use of valproic acid and lamotrigine increases the risk of : 
Select and explain. 
A. Chondrodysplasia punctata, B. Paroxysmal Nocturnal hemoglobinuria, C. Stevens-Johnson syndrome, D. Floppy infant syndrome
C: Stevens-Johnson syndrome
Answer: C: Stevens-Johnson syndrome 
Explanation: Stevens-Johnson syndrome Concomitant use of valproic acid and lamotrigine increases the plasma level of lamotrigine and increases the risk of Stevens-Johnson syndrome; hence, lamotrigine should be staed as a low dose with gradual escalation.