Subcutaneous

Definition

Subcutaneous refers to the layer of tissue located just beneath the skin, and it is also a common route for drug administration. Drugs given subcutaneously are injected into this layer, allowing for slower absorption into the bloodstream compared to other methods like intravenous or intramuscular injection. This route is often used for medications that require a gradual release or those that cannot be taken orally.

5 Must Know Facts For Your Next Test

1. Subcutaneous injections are typically administered using a syringe and needle, with common sites including the abdomen, thigh, and upper arm.
2. The absorption rate of subcutaneously administered drugs can be influenced by factors such as blood flow to the area and the formulation of the drug.
3. This route is advantageous for patients who may have difficulty swallowing pills or those requiring long-term medication management.
4. Certain medications like vaccines can also be given subcutaneously to stimulate an immune response over time.
5. Common subcutaneous medications include insulin, heparin, and some vaccines, making it a versatile method in pharmacotherapy.

Review Questions

• How does subcutaneous administration differ from intravenous administration in terms of drug absorption and onset of action?
  • Subcutaneous administration differs from intravenous administration primarily in the rate at which drugs are absorbed and their onset of action. Subcutaneous injections deliver drugs into the fatty tissue beneath the skin, leading to slower absorption into the bloodstream compared to intravenous injections, which introduce drugs directly into the circulation. This means that subcutaneously administered drugs may take longer to exert their effects, making them more suitable for medications that require gradual release.
• Discuss the advantages and disadvantages of using the subcutaneous route for drug administration.
  • The advantages of using the subcutaneous route include ease of administration, especially for self-injection by patients; reduced risk of infection compared to intravenous routes; and suitability for long-acting medications. However, disadvantages may include limited volume capacity for injections, variability in absorption rates due to factors like body composition and site of injection, and potential discomfort at the injection site. Understanding these pros and cons helps in selecting the appropriate route for specific medications.
• Evaluate how factors such as formulation type and injection site affect the bioavailability of drugs administered subcutaneously.
  • The bioavailability of drugs administered subcutaneously can be significantly influenced by both the formulation type and the injection site. For instance, formulations designed for slow release can enhance the duration of drug action and maintain therapeutic levels over time. Additionally, different injection sites may have varying blood flow rates which can impact how quickly a drug is absorbed into the bloodstream. Understanding these factors is crucial for optimizing drug therapy and ensuring effective patient outcomes.

Related terms

Intravenous: A method of delivering medication directly into the bloodstream through a vein, allowing for rapid absorption and immediate effect.

Bioavailability:

The proportion of a drug that enters the circulation when introduced into the body and is available for therapeutic effect.

Insulin: A hormone commonly administered subcutaneously for the management of diabetes, helping to control blood sugar levels.