What is the likely route of excretion for a volatile drug?

The route of excretion for a volatile drug is most commonly through the lungs. Volatile drugs are substances that can easily vaporize and are typically gases or volatile liquids at normal room temperature. Because of their physical properties, they are often exhaled in the breath after being absorbed into the bloodstream.

The lung's extensive surface area and the rich vascularization allow for efficient gas exchange, making it an ideal route for the excretion of these types of drugs. This process occurs through passive diffusion, where drugs move from areas of higher concentration in the blood to lower concentration in the alveolar air, facilitating their removal from the body.

Other routes of excretion, such as urine or feces, are more typical for drugs that are not volatile and may need to be metabolized or conjugated before elimination. Saliva can contain trace amounts of various substances but is generally not a primary route for the excretion of volatile drugs, which are more efficiently expelled through the respiratory system. Thus, the lungs are uniquely suited for the excretion of these volatile compounds.