This is DR ARPAN JAIN.
As told by you , your mother is a known case of epilepsy
and doctor has prescribed some new drugs. Decrease speech and drowsiness
may be due to the effect of frisum(clobazem- a benzodiazepine
) so, dont worry.
You havnt mentioned her weight as epilex crono dose seems to be subtherapeutic(less) if her weight is more than 5o kg.
now you can stop using frisum and can increase the dose of epilex crono to total dose of 1000 mg (500 mg 2 times a day)