hai. I can c that u have a lot of information to convey but u have missed what is the problem he has now for which u want opinion.
but from ur details I have picked up 2 things:
1) u r from India - bcos liponorm is atorvastatin
made by blue cross Pharma
2) that ur father is having generalized itching
kindly perform a serum IgE
if u want more advice I need to know more specific details.
drug like phenytoin
can produce urticaria
but even stopping these drugs is a trial only but no a definite solution since we don't know the cause yet.
but watch out for withdrawal seizures in ur father.