01.04 Routes of Drug Administration

The routes of drug administration are described as enteral, which means into the gastrointestinal tract, or parenteral (not into the gastrointestinal tract); Figure 1.2.

Figure 1.2 Enteral and parenteral routes of administration (Copyright QUT, Sheila Doggrell)

Routes that are enteral (into the gastrointestinal tract) are oral and rectal. Routes that are parenteral include sublingual (under the tongue) and injection, which can be to a variety of sites e.g. into the vein (intravenous), into the muscle (intramuscular), under the skin (subcutaneous). Other parenteral routes include topical, which is to a body surface, such as the skin, nose, eyes etc. and pulmonary, which is delivery to the lungs. These routes of drug administration are considered in sequence. The route of administration used for a drug may also depend on whether a systemic (around the body) effect is required. Local administration is a way of trying to limit the effects of a drug to a local area.