Where are transdermal patches optimally applied?

• A. Upper arms including deltoids
• B. Face
• C. Soles of the feet
• D. Scalp

Answer: (A)

Transdermal patches deliver medicine through the skin into the bloodstream, so the best site is one with clean, dry, intact skin and good blood flow that allows steady absorption. The upper arm, including the deltoid area, provides a smooth, relatively hair-free surface with decent perfusion, and it’s easy to access for application and for checking the patch. It also tolerates movement well enough that the patch stays in place and can be rotated to prevent skin irritation.

Areas like the face are more sensitive and prone to irritation, and patches on the scalp can be hindered by hair, making adhesion and visibility an issue. The soles of the feet have thick skin and more friction, which reduces absorption and increases the chance a patch will peel off.