What is the process that must occur for medication to have an effect called?

The process that must occur for medication to have an effect is referred to as absorption. Absorption involves the movement of the drug from the site of administration into the bloodstream, allowing it to reach the target tissues where it exerts its effects. This process is critical, as it influences how quickly and effectively the medication begins to work.

Distribution is related but follows absorption; it refers to how the medication disperses throughout the body's fluids and tissues after it has entered the bloodstream. Routes pertain to the specific way a medication is introduced into the body, such as orally or intravenously, but do not define the efficacy directly. Administration simply refers to the act of giving the medication, rather than the process that leads to the medication working. Thus, absorption is the key term that encapsulates the initial process necessary for a medication to take effect.