When applying a transdermal patch, which area should be avoided?

When applying a transdermal patch, it is important to avoid placing it on scars and callouses because these areas can affect the absorption of the medication. Scars may alter the skin's permeability due to changes in the skin's structure and blood flow, while callouses can create a thicker layer of skin that hinders adequate medication uptake. This can lead to reduced effectiveness of the medication, as it may not be absorbed into the bloodstream in the intended amount or at the appropriate rate.

In contrast, applying a patch on dry skin is generally acceptable as it allows for better adhesion and absorption. Areas like arms, legs, or the stomach are typically recommended sites for patch application, depending on the specific instructions for the medication being administered. These areas usually have normal skin that is conducive to adequate absorption, ensuring the medication functions as intended.