Pharmacokinetic parameters

Pharmacokinetic parameters are a set of values that describe the disposition of a drug in the body. These parameters are used to understand how the body affects a specific drug after administration. They are crucial in the development and testing of new drugs, as well as in the optimization of drug therapy for individual patients.

Overview

Pharmacokinetic parameters are derived from the four fundamental processes of pharmacokinetics: absorption, distribution, metabolism, and excretion (ADME). These processes determine the concentration of the drug in the body over time, which in turn influences the drug's therapeutic and toxic effects.

Key Pharmacokinetic Parameters

Absorption

• Bioavailability: The fraction of an administered dose of a drug that reaches the systemic circulation intact. It is a key factor in determining the dosage of a drug.

Distribution

• Volume of Distribution (Vd): A hypothetical volume that represents the extent to which a drug is distributed in the body relative to its concentration in the blood plasma.

Metabolism

• Clearance (Cl): A measure of the body's efficiency in eliminating a drug from the bloodstream.

Excretion

• Half-life (t1/2): The time it takes for the concentration of the drug in the body to decrease by half.

Factors Influencing Pharmacokinetic Parameters

Several factors can influence pharmacokinetic parameters, including age, sex, body weight, genetic factors, disease states, and interactions with other drugs.

Clinical Significance

Understanding pharmacokinetic parameters is essential for healthcare professionals to optimize drug therapy, minimize side effects, and avoid drug interactions.