I want to know if there is any snake bit first aid drug that can be bought, kept at home and taken as first aid, before taken victim to hospital ?

No.: Snake bite antivenin is extremely expensive and requires medical supervision to give it and to monitor for side effects. It is great that you are making up a first aid kit though! Everyone should do so. By the way: diphenhydramine (Benadryl), liquid and capsule forms, should be in everybody's medicine cabinet, to prevent potentially fatal allergic reactions which can occur without warning.