Answer Happy

Normal values for the pharmacokinetic parameters clearance,
fraction unbound, and fraction excreted unchanged are listed in the
table for drugs A through E. Situations are presented which
alter the kinetics of each of these drugs. On the right
indicate whether the value of each parameter would be observed to
increase, decrease, or show little or no change. All drugs
are administered orally and have volumes of distribution greater
than 50 litres. Assume GFR is 7.2 L/hr and QH is 90
L/hr
Normal Values Fraction Unbound in Blood 0.9 0.5 0.02 0.1 Drug Systemic Clearance (L/hr) A 3.5 B 80 с 1 D 3 CLR = (fu *GFR+CL)(1-FR) For Low En drugs: CL₁ fu*CLint Fraction Excreted Unchanged in Urine 0.95 0.02 0.1 0.05 Situations Simultaneous administration of a competitive inhibitor of renal secretion Simultaneous administration of an inducer of metabolism Simultaneous administration of a drug that displaces drug D from plasma proteins Administration of an enzyme inhibitor for several days = 0.693 * V CL For High En drugs: CL₁Q₁ Systemic Volume of Clearance Distribution fH = 1-EH Observation and Half-life F=fc *fH Bioavailability