This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
A 25yr old women with myoclonic seizures is well controlled on valproate. she indicates that she is intrested in conceiving in next year. With respect to her antiepileptic medication, wof should be considered 
Select and explain. 
A. Leave her on current therapy, B. Switch to lamotrigine, C. Decrease valproate dose, D. None of the above
B: Switch to lamotrigine
Answer: B: Switch to lamotrigine 
Explanation: Lamotrigine Mech of action:- Lamotrigine is a broad-spectrum antiepileptic. It modifies maximal electric shock and decreases electrically evoked as well as photic after-discharge duration. Prolongation of Na+ channel inactivation and suppression of high frequency firing has been demonstrated. In addition, it may directly block voltage sensitive Na+ channels, thus stabilizing the presynaptic membrane and preventing release of excitatory neurotransmitters, mainly glutamate and aspaate. This may account for its broader-spectrum of antiseizure efficacy. uses:- Absence and myoclonic or akinetic epi-lepsy cases have also been successfully treated. Reduction in seizure frequency or complete control is obtained as frequently as with carbamazepine. Pharmacokinetics:- Lamotrigine is well absorbed orally and metabolized completely in liver. Its t 1/2 is 24 hr, but is reduced to ~16 hr in patients receiving phenytoin, carbamazepine or phenobarbitone. On the contrary valproate inhibits glucuronidation of lamotrigine and doubles its blood level, but valproate levels are lowered by lamotrigine. Reduce the dose of lamotrigine to half in patients taking valproate. However, metabolism of other anticonvulsants and oral contraceptives is not altered. Ref:- kd tripathi;pg num:-419