Search results
Results from the WOW.Com Content Network
In pharmacokinetics, steady state refers to the situation where the overall intake of a drug is fairly in dynamic equilibrium with its elimination. In practice, it is generally considered that once regular dosing of a drug is started, steady state is reached after 3 to 5 times its half-life. In steady state and in linear pharmacokinetics, AUC ...
Absorption half-life 1 h, elimination half-life 12 h. Biological half-life (elimination half-life, pharmacological half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration (C max) to half of C max in the blood plasma.
It was proposed to be used instead of AUC in animal-to-human dose translation, as computer simulation shows that it could cope better with half-life and dosing schedule variations than AUC. This is an example of a PK/PD model, which combines pharmacokinetics and pharmacodynamics. [13]
In pharmacology, clearance is a pharmacokinetic parameter representing the efficiency of drug elimination. This is the rate of elimination of a substance divided by its concentration. [ 1 ] The parameter also indicates the theoretical volume of plasma from which a substance would be completely removed per unit time.
The biological half-life of progesterone in the circulation is very short; with intravenous injection, its half-life has ranged widely from 3 to 90 minutes in various studies. [14] The metabolic clearance rate of progesterone ranges between 2,100 and 2,800 L/day, and is constant across the menstrual cycle. [14] [211
[2] [3] The pharmacokinetics of testosterone, including its bioavailability, metabolism, biological half-life, and other parameters, differ by route of administration. [2] Likewise, the potency of testosterone, and its local effects in certain tissues, for instance the liver, differ by route of administration as well. [2]
The plasma half-life or half life of elimination is the time required to eliminate 50% of the absorbed dose of a drug from an organism. Or put another way, the time that it takes for the plasma concentration to fall by half from its maximum levels.
Half-life has units of time, and the elimination rate constant has units of 1/time, e.g., per hour or per day. An equation can be used to forecast the concentration of a compound at any future time when the fractional degration rate and steady state concentration are known: