1.9:
Routes of Drug Administration: Overview
Drugs can be administered through various routes, such as enteral, parenteral, and topical. The route choice depends on the drug's properties and the therapeutic aim.
Enteral administration delivers a drug through the gastrointestinal or GI tract. The drug can be administered perorally, or swallowed by mouth, sublingually or placed under the tongue, or buccally, that is placed on the cheeks' inner lining.
Perorally administered drugs take time to get absorbed and reach the systemic circulation. So they usually have the slowest onset of action.
Parenteral administration delivers the drug directly into the circulation. It can be injected intravenously or through the veins, intramuscularly or through the muscles, or subcutaneously under the skin.
Intravenous drugs have high bioavailability and rapid onset of action. This route is often used during emergencies.
In topical administration, the drug is applied directly to an area of the skin or mucous membrane through ointments or sprays. The absorption of the drug depends on its properties and the vascularity of the local tissue.
1.9:
Routes of Drug Administration: Overview
Drug administration involves delivering drugs to the body through various routes, such as enteral, parenteral, and topical.
Enteral administration refers to drugs absorbed through the gastrointestinal tract. They can be swallowed (perorally), placed under the tongue (sublingually), or on the inner lining of the cheeks (buccally). Perorally administered drugs take time to be absorbed and have a slower onset of action. The rectal route is another form of enteral administration, which allows for faster absorption through the rectal mucosa.
Parenteral administration involves delivering drugs directly into the bloodstream. This can be done through intravenous (IV), intramuscular (IM), or subcutaneous (under the skin) injections. IV drugs have high bioavailability and provide a rapid onset of action, making them suitable for emergencies.
Topical administration involves using ointments or sprays to apply drugs directly to the skin or mucous membranes.
Absorption is the process of a drug moving from the administration site into the bloodstream. It is crucial for all routes of administration except for intravenous injection, where absorption is immediate. In most cases, the drug must enter the bloodstream before reaching its site of action.
Other routes of administration include application to epithelial surfaces, inhalation, transnasal, vaginal, intrathecal, intraosseous,and intravitreal injections.
The choice of administration route is primarily determined by the drug's properties, such as solubility and ionization, as well as therapeutic objectives and target location. Enteral administration is commonly used for its safety, convenience, and cost-effectiveness. Parenteral routes are preferred for drugs with poor GI absorption, unstable in the GI tract, or requiring rapid action. Topical administration is suitable for localized treatment.