36. At very high concentrations — concentrations muchhigher than the drug’s Km–drugs are more likely to approachzero-order elimination
A. True
B. False
37. A patient, JH, is administered phenytoin free acid,300 mg/day for 2 months (assume steady state is achieved), and aplasma concentration determined just before a dose is 10 m . Thephenytoin dose is then changed to 400 mg/day; 2 months after thedose change, the plasma concentration determined just before a doseis18 mg/L. Assume that the volume of distribution of phenytoin is45 L. Calculate Km for this patient.
A. 12.9mg/L
B. 25 mg/L
C. 37.5 mg/L
D. 10 mg/L
38. A patient, JH, is administered phenytoin free acid,300 mg/day for 2 months (assume steady state is achieved), and aplasma concentration determined just before a dose is 10 mg/L. Thephenytoin dose is then changed to 400 mg/day; 2 months after thedose change, the plasma concentration determined just before a doseis18 mg/L. Assume that the volume of distribution of phenytoin is45 L. For the same patient, JH. determine Vmax.
A. 123 mg/day
B. 900 mg/day
C. 500 mg/day
D. 687 mg/day
