How are drugs administered through transdermal means?

Transdermal drug administration involves delivering medication through the skin using a patch. This method allows the active ingredients of the drug to be absorbed slowly into the bloodstream over time, providing a continuous release of medication and maintaining stable drug levels in the body.

Transdermal patches are often used for various treatments, such as pain management (e.g., fentanyl patches), hormone replacement therapy (e.g., estrogen patches), and smoking cessation (e.g., nicotine patches). This method bypasses the gastrointestinal tract and the potential issues associated with oral administration, such as first-pass metabolism in the liver, enabling more consistent drug levels.

The other methods of administration listed involve different routes that do not engage the skin's absorption capabilities, hence they are not considered transdermal. Inhalation delivers the drug directly to the lungs; swallowing involves the digestive system; and injection targets directly into the bloodstream or tissues. Transdermal delivery stands out as a unique and effective method designed specifically for skin absorption.