Oral/ Enteral route:

• Oral (per oral P.O or PO) route refers to administration of drugs by ingestion.
• Oldest, easiest and commonest method of drug administration.
• Drugs are administered orally either in the form of drenches or mixed in feed or water. After oral administration, drug passes through the gastrointestinal wall and travels to the liver before it is transported via bloodstream to its target site.
• Drugs given before meal are rapidly absorbed from an empty stomach.

Advantages:

• Safest, least expensive and commonest route of drug administration.
• Most convenient for patient
• It doesn’t require sterilization of drug preparation
• Most suitable route for gastrointestinal tract infections and parasites.
• Large volume of liquid drug preparation can be administered.
• In case of drug sensitivity, the ingested drug can be removed from stomach.

Disadvantages:

• It is not suitable for emergency situations and in critically ill patient.
• It is not suitable for uncooperative, unconscious or vomiting patient.
• Some drugs are ineffective by oral route because they are destroyed rapidly in the stomach or rumen.
• Strong electrolyte or highly polar drugs are not absorbed by oral route because they remain largely ionized in the G.I tract.
• Long-term administration of some drugs may either cause damage to gastro-intestinal mucosa or destroy gut microflora causing superinfection.