Home » Notes » Nursing Fundamentals and Skills » Transdermal Patches and Medications

Transdermal Patches and Medications

Published on
By Paul Martin, BSN, R.N.

Transdermal drug delivery offers a convenient method to administer medication, avoiding the discomfort of intravenous injections, the need for venous access, and the disposal of syringes. It also provides an alternative for patients with difficulty swallowing oral medications as it bypasses first-pass metabolism, avoids gastrointestinal issues, and improves patient compliance.

Table of Contents

What is Transdermal Medications?

Transdermal medication refers to the administration of drugs through the skin for systemic distribution. These medications are delivered via patches that are applied to the skin, allowing for a slow and controlled release of the drug into the bloodstream.

Mechanism of Transdermal Patches

Transdermal patches work through several key layers:

  • Backing Layer. Protects the patch from external elements.
  • Drug Reservoir/Matrix. Contains the medication.
  • Release Liner. Protects the drug during storage and is removed before application.
  • Adhesive Layer. Ensures the patch sticks to the skin.

The medication in the patch is released at a controlled rate, passing through the skin layers (stratum corneum, epidermis, and dermis) and entering the capillaries to be distributed throughout the body.

Advantages

Transdermal patches provide the following several benefits:

  • Controlled release. Provides a constant and controlled release of medication over time.
  • Easy to use and non-invasive. It offers an alternative to injections, reducing pain and risk of infection.
  • Digestive system bypass. By avoiding the digestive tract, transdermal patches minimize the impact of stomach acid on the medication.
  • Direct bloodstream delivery. Transdermal patches bypass liver processing, delivering medication more directly to the bloodstream.

Disadvantages

While transdermal patches provide a convenient and steady method of drug delivery, they also come with some disadvantages:

  • Can cause local skin reactions. Some patients may experience allergic reactions or irritation at the application site.
  • Variable absorption. Skin permeability can vary between individuals and at different sites on the body, leading to inconsistent drug absorption.
  • Generally more expensive. Transdermal systems can be more expensive to manufacture than traditional oral medications.
  • Limited drug types. Only drugs with specific molecular properties (e.g., small molecular size, lipophilicity) can be effectively delivered transdermally.

Types of Transdermal Patches

Understanding these different types of transdermal patches helps in selecting the appropriate design based on the desired drug delivery profile and therapeutic needs.

1. Single-layer Drug-in-Adhesive.
This type of patch has a single adhesive layer that contains the drug. The adhesive layer serves as both the adhering agent and the drug reservoir, which releases the drug through the skin. These patches are simple in design and easy to manufacture.

2. Multi-layer Drug-in-Adhesive.
Similar to the single-layer patch, but with multiple layers of adhesive, each containing the drug. This design allows for a more controlled release of the drug over time. Each layer can have different drug concentrations, enabling a more complex delivery profile.

3. Reservoir.
This type of patch has a separate drug reservoir, which is encased between a backing layer and a rate-controlling membrane. The drug is released through the membrane at a controlled rate, allowing for precise control over the dosage. These patches often provide a more consistent and prolonged drug delivery.

4. Matrix.
In matrix patches, the drug is embedded in a matrix layer, which is placed between the backing layer and the adhesive layer. The drug diffuses through the matrix and then through the adhesive to the skin. This design can provide a steady release of medication over time.

5. Vapor Patches.
These patches release essential oils or other substances that vaporize and are inhaled rather than absorbed through the skin. They are commonly used for aromatherapy or to deliver medications that benefit from inhalation.

6. Micro-reservoir.
This design combines the reservoir and matrix types. The drug is suspended in a solution and formed into tiny reservoirs within a gel-like matrix. This structure allows for a controlled and sustained release of the drug.

Types of Drugs Administered Through Transdermal Patches

Transdermal patches are used for various therapeutic purposes and deliver different types of medications. Here are some common examples:

Side Effects

Common side effects of transdermal medications include:

  • Local skin reactions. Redness, itching, rash, or swelling at the application site.
  • Systemic side effects. Depending on the drug, may include dizziness, nausea, headache, or other drug-specific side effects.
  • Allergic reactions. Rare but possible, requiring immediate medical attention.

How to Apply Transdermal Medication?

Proper application of transdermal medication is key to achieving effective drug delivery and reducing side effects. This guide provides a detailed step-by-step process:

1. Before applying the new patch, review the physician’s order or the drug label for placement instructions, which suggest the upper chest, upper outer arm, lower abdomen, or hip.
This ensures efficient skin absorption, minimizing the chance of uneven drug effects and maximizing therapeutic benefits, ensuring patient safety and comfort.

2. Remove any old patches containing the same drug by peeling back an edge and gently pulling it off. Fold it with sticky sides together and discard it.
Correct disposal of old patches maintains consistent dosing, prevents overdose, and avoids irritation.

3. Clean the application area with clear water, pat it dry completely, and avoid using soaps, alcohols, lotions, or oils before applying the patch.
Clean, dry skin free of any residue optimizes the patch’s ability to adhere and function effectively.

4. Carefully open the pouch and remove the patch without touching the adhesive side.
Proper handling prevents contamination and maintains the patch’s adhesive quality.

5. Immediately press the adhesive side of the patch onto the skin using the palm of the hand. Applying the patch immediately enhances strong adhesion and maximizes its effectiveness.

6. Hold the patch firmly in place for at least 30 seconds, ensuring it sticks well, especially around the edges.
Firm pressure enhances adhesion, preventing the patch from coming loose.

7. Use first-aid tape to secure the edges if the patch becomes loose. If needed, see-through dressings can be used.
Reinforcing the patch ensures it stays in place, maintaining consistent drug delivery.

8. If a patch falls off prematurely, dispose of it properly and apply a new patch, maintaining the original dosing schedule. Inform the physician or pharmacist in such cases.
Ensuring consistent dosing prevents interruptions in medication therapy.

9. Wash hands with water immediately after applying the patch.
Washing hands prevents accidental transfer of medication to other areas or people.

10. When changing the patch, apply the new one to a different skin area.
Rotating the application site prevents skin irritation and improves patch effectiveness.

11. Fold the used patch with adhesive sides together and dispose of it properly.
Proper disposal prevents accidental exposure to medication and environmental contamination.

Nursing Considerations

Follow these additional instructions when applying transdermal medication:

1. Choose an appropriate patch placement by selecting an area of skin that facilitates good adhesion.
Select a skin area that is clean, dry, and free from hair, excessive sweat, or cuts. This guarantees the patch adheres securely, enhancing drug absorption and effectiveness.

2. Rotate patch application sites.
Rotate the patch placement between different areas of the body (e.g., upper arm, abdomen, hip) to minimize skin irritation and maximize patch effectiveness over time.

3. Considering skin thickness for patch placement.
Avoid placing patches on skin that is excessively thin or thick, as this can affect drug absorption.

4. Advise to keep the patch dry and avoid prolonged exposure to water or moisture.
Avoid exposing patches to water or excessive moisture, as this can compromise their ability to adhere to the skin and deliver medication effectively.

5. Do not apply new patches over areas where previous patches were placed.
Overlapping patches can lead to unintended drug interactions or overdosing.

Sources and References

Paul Martin R.N. brings his wealth of experience from five years as a medical-surgical nurse to his role as a nursing instructor and writer for Nurseslabs, where he shares his expertise in nursing management, emergency care, critical care, infection control, and public health to help students and nurses become the best version of themselves and elevate the nursing profession.

Leave a Comment


Share to...