What is a prodrug?

A prodrug is defined as an inactive compound that undergoes metabolic conversion within the body to become an active pharmacological agent. This activation usually occurs after administration, where the prodrug is converted into its active form through various metabolic processes, often involving enzymatic reactions in the liver or other tissues. This mechanism allows for improved absorption, distribution, and sometimes a reduction in toxicity of the drug as the active form is released at the ideal site of action.

For this reason, the answer accurately reflects the nature of prodrugs and their role in pharmacology. Other options refer to characteristics that do not distinctly define a prodrug. For example, a drug that acts immediately upon administration is not fitting the prodrug definition, as prodrugs require activation. Similarly, compounds that are eliminated solely through urine or drugs that induce sedation do not pertain to the prodrug classification, as these descriptions focus on elimination routes and effects rather than the activation process that defines prodrugs.