四、一藥物以口服途徑給予,在胃腸道的藥量以 DGI(amount of drug in the GI tract)表示,假設藥物在體內可均勻分布,其擬似分布體積(apparent volume of distribution)為 VD,而在體內藥量為 DB(amount of drug in body),藥物的排除量(amount of drug eliminated)則為 DE,請回答下列問題:
(一)請畫出口服後血中藥物濃度經時變化圖形(plasma drug concentration- time profile)。(5 分)