following fall is one of the reasons for seizures and there are many. The type and pattern of seizures, the EEG report and MRI
scan of brain will collectively help a doctor understand the situation and start the patient on best possible therapy with least side effects,
is known to have side effects in long run, may be its time to switchover to better and more effective drugs.
Shivering and weakness may not be related to seizures but may be due to many othe reasons including infections etc
I request you to follow up with the reports/tests mentioned above for deciding the plan. also do provide me details about seizure, describing exactly what how and how long etc
I hope this answers yoru query. consult for detailed advice.