What is the importance of routes of drug administration in Pharmacotherapy?

The importance of routes of drug administration in pharmacotherapy include;

1. This route is of prime importance in emergency.
2. It is the only route for giving large volume of drugs e.g. blood transfusion.
3. It is safe, convenient, cheap and does not require the services of a skilled personnel.
4. Blood from intestinal tract passes via portal vein to the liver where the drug may be metabolized to a great extent before being distributed to the site of action.
5. Venous drainage from mouth is poured into the superior vena cava and the drug is saved from first pass effect.