National Certified Addiction Counselor, Level 2 (NCAC II) Practice Exam Exam

How does the route of inhalation facilitate the entry of drugs into the bloodstream?

1. Through the stomach

2. Through the gastrointestinal tract

3. Through the lungs

4. Through the skin

The correct answer is: Through the lungs

Inhalation is an effective route for drug administration due to the unique properties of the lungs and the respiratory system. When drugs are inhaled, they travel directly into the alveoli, the tiny air sacs in the lungs where gas exchange occurs. The alveolar walls are extremely thin and are surrounded by a rich network of capillaries, which allows for rapid absorption of substances into the bloodstream. This route bypasses the digestive system and its metabolic processes, which can alter or degrade drugs before they reach circulation, as would occur with options involving the stomach or gastrointestinal tract. Additionally, inhalation avoids the epidermal barrier that would be encountered with transdermal (through the skin) routes. The rapid absorption through the lungs is particularly important for substances that require quicker onset of action, making inhalation a preferred method for certain drugs, especially in emergency situations or for medications affecting the central nervous system.