What process involves medication molecules temporarily attaching to proteins in the blood plasma?

The process where medication molecules temporarily attach to proteins in the blood plasma is referred to as plasma protein binding. This is a critical pharmacokinetic concept that affects how drugs are distributed throughout the body and can influence their therapeutic effects.

When a drug enters the bloodstream, it can bind to various plasma proteins, predominantly albumin. The binding is usually reversible, meaning that the molecules can detach and then bind again. Only the unbound or "free" drug is active and able to exert a therapeutic effect. Consequently, the extent of plasma protein binding can significantly impact the drug's availability and efficacy, as well as its duration of action.

In contrast, free drug distribution refers to the availability of unbound drug to tissues, metabolic clearance relates to the elimination of the drug from the body, and volume of distribution is an estimate of how extensively a drug disperses into body tissues relative to the plasma. These concepts are also important in understanding drug dynamics but do not specifically describe the process of medication molecules attaching to proteins in the plasma.