National Certified Addiction Counselor, Level I (NCAC I) Practice Exam

What is a unique characteristic of amphetamine metabolism?

1. Metabolized primarily by the liver

2. Excreted in urine unchanged

3. Has a half-life of less than five hours

4. Converted to inactive metabolites in the gut

The correct answer is: Excreted in urine unchanged

Amphetamines, such as dextroamphetamine and methamphetamine, are indeed unique in their metabolic pathway. A notable characteristic is that a significant portion of amphetamines is excreted in the urine in an unchanged form. This means that rather than being metabolized extensively into different compounds, many of the amphetamine molecules remain intact and are eliminated from the body via the renal system. This feature is particularly important in understanding the drug's pharmacokinetics, including how long it remains active in the body and how it can be detected in urine screenings. The unchanged excretion can be influenced by factors such as urine pH; for example, more acidic urine can promote the ionization of amphetamines, which may reduce their excretion rate. In contrast, metabolism primarily by the liver, a half-life of less than five hours, and conversion to inactive metabolites in the gut do not accurately emphasize this unique aspect of amphetamine metabolism, emphasizing the importance of the unchanged excretion in understanding how amphetamines function and linger in the system.