enteral route

The enteral route covers any way of giving a drug through the gastrointestinal tract — the tube running from mouth to anus. The name comes from enteron, Greek for gut. In practice it groups together the oral route (swallowing), administration through a feeding tube into the stomach or intestine, and the rectal route. It is the natural counterpart of the parenteral route, which bypasses the gut.

What unites enteral routes is that the drug must be absorbed across the lining of the digestive tract to reach the blood, and that anything absorbed from most of the gut first passes through the liver via the portal vein, where it may undergo first-pass metabolism. They also share exposure to gut contents, pH changes, and digestive enzymes.

The enteral route is the most physiological and convenient way to give medicines and is preferred whenever a drug is reliably absorbed and the patient can use it. Feeding tubes (nasogastric or gastrostomy) extend the enteral route to patients who cannot swallow but still have a working gut.

A common source of confusion is treating 'enteral' as a synonym for 'oral'. Oral is one enteral route, but enteral is the broader category that also includes rectal and tube administration. The defining feature is use of the gut, not specifically the mouth.