What are the three primary routes of drug administration?

• A. Oral, inhaled, injected
• B. Topical, oral, subcutaneous
• C. Nasal, sublingual, oral
• D. Injected, oral, transdermal

Answer: (A)

The three primary routes of drug administration encompass oral, inhaled, and injected methods.

Oral administration is the most common route due to its ease and ability to deliver medication directly to the gastrointestinal tract where it can be absorbed into the bloodstream. Inhaled medications, often used for respiratory conditions, enter the body through the lungs, allowing for rapid absorption and onset of action due to the large surface area and rich blood supply in the pulmonary system. Lastly, injected routes, which include intramuscular, subcutaneous, and intravenous, provide direct entry into the bloodstream or tissues, facilitating a quick therapeutic effect.

These routes are fundamental because they cover a broad spectrum of patient needs and drug characteristics, allowing for flexibility in treatment approaches. Each of the other options includes certain valid routes but does not encapsulate the three most essential forms as comprehensively as the selected answer.