Steady-state arterial and hepatic venous plasma concentrations of 5-bromo-2'-deoxyuridine and 5-iodo-2'-deoxyuridine in animals--drugs which are subject to both splanchnic and extra-splanchnic elimination

Compartment model to describe peripheral arterial-venous drug concentration gradients with drug elimination from the venous sampling compartment

The central compartment of an n-compartment mammillary model was concatenated with a gradient compartment (i.e., venous sampling compartment) and with a conventional effect compartment to model arterial-venous drug concentration gradients and the arterial drug concentration vs effect relationship, respectively. To model drug metabolism during transit between the peripheral arterial and peripheral venous circulations, the gradient compartment included a first-order elimination path. Simulations of the model were employed to demonstrate the impact of sampling site (e.g., arterial vs peripheral venous) on analyses of the concentration vs effect relationship.

Absorption of flurbiprofen in the fed and fasted states

The oral absorption of flurbiprofen, an antiinflammatory nonsteroidal compound, was compared in the fasted vs the fed state. When ingested as an aqueous solution of the sodium salt, absorption kinetics followed a monoexponential pattern in half of the subjects and a bimodal pattern with a lag time before the onset of the second phase of absorption in the other half of the subjects. When ingested in the free acid form as a tablet either with water (fasted state) or with water 15 min after 330 ml of apple juice (fed state), flurbiprofen absorption was always bimodal, and the lag time before the onset of the second phase was shown to be dependent on the gastric emptying time (r = 0.623, P less than 0.01). The gastric emptying times were significantly longer when the drug was administered in the fed state (average GET = 57 min in the fasted state and 102 min in the fed state; P less than 0.01). These results suggest that gastric emptying effects are one important way in which absorption of drugs can be affected by meal intake.