An upper bound for the half-removal time of neutrophils from circulation

Clearance measures drug elimination from the central compartment, including plasma and highly perfused organs like kidneys and liver. Its calculation varies depending on pharmacokinetic models and administration routes. The one-compartment model, for instance, portrays the pharmacokinetics of polar drugs such as aminoglycoside antibiotics administered intravenously and readily excreted in urine. In this case, clearance is influenced by the terminal rate constant (λz) and the total volume...

Clearance is a pharmacokinetic parameter traditionally defined by compartment models, signifying the rate at which a drug is expelled from the body. However, a noncompartmental model offers an alternative method for assessing clearance, primarily employing empirical data obtained after administering a single drug dose.
The noncompartmental approach capitalizes on extensive sampling data, correlating the volume of distribution to systemic exposure and the administered dosage. This method enables...

The elimination half-life and drug clearance of drugs following nonlinear kinetics can vary with dosage. The Michaelis-Menten parameters and drug concentration influence these factors. As the dose increases, the elimination half-life tends to lengthen, resulting in a reduction in clearance and a disproportionately larger area under the curve. The total clearance can be derived from the Michaelis-Menten equation for drugs following a one-compartment model.
A study on guinea pigs examined the...

Hepatic clearance refers to the volume of blood cleared of a drug by the liver per unit of time. It plays a crucial role in drug metabolism and elimination. While hepatic clearance is commonly estimated by subtracting renal clearance from total body clearance, other pathways, such as pulmonary or biliary clearance, may also contribute. However, these pathways are generally less significant than hepatic and renal clearance.
Most drugs undergo restrictive clearance, which is proportional to the...

Clearance is a key pharmacokinetic parameter that quantifies the volume of body fluid from which a drug is entirely removed within a specific time frame. It is crucial in assessing how a drug is eliminated from the body and has critical clinical applications.
In the one-compartment open model for intravenous (IV) bolus administration, clearance is estimated by dividing the elimination rate by the plasma drug concentration. This equation leverages the elimination rate constant and the apparent...

Drug elimination from the body primarily occurs through metabolic and excretion pathways. Hepatic metabolism transforms lipophilic drugs into hydrophilic forms for excretion, typically via enzymatic processes classified as phase I (modification) and phase II (conjugation). Renal excretion eliminates drugs and metabolites through filtration and secretion in the kidneys. Impairment in liver or kidney function can hinder these processes, delaying drug clearance and extending the drug’s...