Search results
Results From The WOW.Com Content Network
The accumulation ratio of a specific drug in humans is determined by clinical studies. According to a 2013 analysis, such studies are typically done with 10 to 20 subjects who are given one single dose followed by a washout phase of seven days , and then seven to 14 repeated doses to reach steady state conditions. Blood samples are drawn 11 ...
Clearance of a substance is sometimes expressed as the inverse of the time constant that describes its removal rate from the body divided by its volume of distribution (or total body water). In steady-state, it is defined as the mass generation rate of a substance (which equals the mass removal rate) divided by its concentration in the blood.
In pharmacokinetics, the rate of infusion (or dosing rate) refers not just to the rate at which a drug is administered, but the desired rate at which a drug should be administered to achieve a steady state of a fixed dose which has been demonstrated to be therapeutically effective. Abbreviations include K in, [1] K 0, [2] or R 0.
The elimination rate constant K or K e is a value used in pharmacokinetics to describe the rate at which a drug is removed from the human system. [1] It is often abbreviated K or K e. It is equivalent to the fraction of a substance that is removed per unit time measured at any particular instant and has units of T −1.
This gives a = 100 μg/mL if the drug stays in the blood stream only, and thus its volume of distribution is the same as that is = 0.08 L/kg. If the drug distributes into all body water the volume of distribution would increase to approximately V D = {\displaystyle V_{D}=} 0.57 L/kg [ 8 ]
The formula for calculating the absolute bioavailability, F, of a drug administered orally (po) is given below (where D is dose administered). F a b s = 100 ⋅ A U C p o ⋅ D i v A U C i v ⋅ D p o {\displaystyle F_{\mathrm {abs} }=100\cdot {\frac {AUC_{\mathrm {po} }\cdot D_{\mathrm {iv} }}{AUC_{\mathrm {iv} }\cdot D_{\mathrm {po} }}}}
Absolute bioavailability refers to the bioavailability of a drug when administered via an extravascular dosage form (i.e. oral tablet, suppository, subcutaneous, etc.) compared with the bioavailability of the same drug administered intravenously (IV). This is done by comparing the AUC of the non-intravenous dosage form with the AUC for the drug ...
In survival analysis, the hazard ratio (HR) is the ratio of the hazard rates corresponding to the conditions characterised by two distinct levels of a treatment variable of interest. For example, in a clinical study of a drug, the treated population may die at twice the rate of the control population.