What role do transport proteins play in pharmacokinetics?

Transport proteins play a crucial role in pharmacokinetics by facilitating the movement of drugs across cell membranes. This is essential for the absorption, distribution, and excretion of drugs in the body. They can be categorized into two main types: influx and efflux transporters.

Influx transporters help bring drugs into cells, which can enhance drug absorption in the gastrointestinal tract or allow for the uptake of drugs into target tissues. Conversely, efflux transporters can move drugs out of cells, which is important for preventing toxicity and regulating drug levels within tissues.

The action of transport proteins can influence a drug's bioavailability, its ability to reach therapeutic targets, and its overall pharmacological effects. Since pharmacokinetics involves understanding how drugs move through the body and how they are processed, the role of transport proteins is fundamental in determining the fate of a drug after administration.