Drug administration

• The three routes of drug administration are enteral, parenteral, and topical. • The drug route may produce systemic effects, local effects, or both. • Oral drugs may be available in sustained-release or enteric-coated form to delay onset of action of the drug. • Food, fl uids, and other drugs may alter the absorption of enteric drugs. • The parenteral route avoids the GI tract and the irregularities of absorption, including the fi rst-pass effect. The most common methods of parenteral drug administration are the IM, SC, and IV routes. • Onset of drug action is more rapid with the parenteral than with the enteral route. • Patient characteristics (age, weight, muscle mass) and drug characteristics (volume, viscosity, irritability) are considered when selecting a site for IM drug administration. • Administration of IV drugs may be through continuous drip, intermittent infusion, or IVP methods into peripheral or central venous access devices. IV drugs are normally administered via a pump or controller to maintain a steady, safe rate of drug delivery. • Topical drugs include those that are applied to the skin and mucous membranes of the eyes, ears, nose, rectum, and vagina.