Geneesmiddeleneliminatie: Het concept van klaring

Administered drugs circulate in the blood plasma until they are removed by the kidneys through urine or by the liver via bile. Drug clearance is a pharmacokinetic parameter that measures how efficiently the body removes the drug from systemic circulation within a specified time.

 Drug clearance is measured as the rate at which a drug is eliminated from plasma divided by the plasma concentration of the drug. It is the most crucial parameter for designing a rational dosage regimen.

If the bioavailability of a drug is assumed to be 100%, clearance helps determine the dosing rate needed to achieve a steady-state concentration of the drug in plasma.

As long as the correct dosing rate is maintained, the body clears a constant fraction of the drug per unit of time. Increasing the drug concentration beyond the prescribed dosing rate overburdens elimination pathways and decreases drug clearance.

This raises plasma drug concentrations to toxic levels, leading to one or more adverse effects.