Drugs pharmacokinetic versus

Thus, %F is defined as the area under the curve normalized for administered dose. Blood drug concentration is affected by the dynamics of dissolution, solubility, absorption, metabolism, distribution, and elimination. In addition to %F, other pharmacokinetic parameters are derived from the drug concentration versus time plots. These include the terms to describe the compound s absorption, distribution, metabolism and excretion, but they are dependent to some degree on the route of administration of the drug. For instance, if the drug is administered by the intravenous route it will undergo rapid distribution into the tissues, including those tissues that are responsible for its elimination. 

FIG. 3-1. Single-dose plasma drug concentration versus time curves for the same dose of the same drug given to the same individual by three different routes. (From Janicak PG, Davis JM. Pharmacokinetics and drug interactions. In Sadock BJ, Sadock V, eds. Kaplan Sadock s comprehensive textbook of psychiatry, Vol. 2, 7th ed. Philadelphia Lippincott Williams Wilkins, 2000 2251, with permission. Artwork created by Matthew Janicak.)... 

Mehvar, R. Jamali, F. Bioequivalence of chiral drugs. Stereospecific versus non-stereospecific methods. Clin. Pharmacokinet. 1997, 33, 122-141. 

Cp)max is not restricted to a time at which blood was collected but is based on the pharmacokinetic fit to all the plasma drug concentration versus time data it will, therefore, be more accurate. 

In many cases pharmacokinetic data (i.e. plasma drug concentration versus time data) cannot be fitted to an explicit equation equivalent to a system containing a discrete number of compartments into which dmg distributes. This data analysis requires some form of non-compartmental analysis (also referred to as model-independent analysis.) This is achieved by the use of statistical moment theory. 

Specifically, the pharmacokinetic curve involved in this case is the curve representing the plasma drug concentration versus time function and, even when this function is not explicitly known, the area under the curve (AUC) can be estimated by a technique called the trapezoidal approximation. Briefly stated, this divides the... 

FIGURE 1 Pharmacokinetics versus pharmacodynamics. Pharmacokinetics deals with the phases of drug absorption, drug distribution, and drug elimination. Pharmacodynamics defines the biological effect of a drug at a site of action. 

Figure 7.23 Relative acceptor compartment concentrations versus octanol-water apparent partition coefficients [550]. [Reprinted from Kansy, M. Fischer, H. Kratzat, K. Senner, F. Wagner, B. Parrilla, I., in Testa, B. van de Waterbeemd, H. Folkers, G. Guy, R. (Eds.). Pharmacokinetic Optimization in Drug Research, Verlag Helvetica Chimica Acta Zurich and Wiley-VCH, Weinheim, 2001, pp. 447-464, with permission from Verlag Helvetica Chimica Acta AG.]...

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