PHAR 4634 Pharmaceutics III

Chapter 5

Homework Assignment - 1997 #2 - Again not to be graded!

1. Assume that a one compartment pharmacokinetic model applies. Calculate the cumulative amount of unchanged drug excreted into urine up to the times 1, 2, 4, 6, 9, and 12 hours after a 400 mg i.v. bolus dose. Use kel = 0.21 hr^-1; V = 24.8 L; and fe = 0.55.

Answer

2. Given the data in Table 1, below, calculate kel, ke, and fe after an IV Bolus dose of 400 mg. Assume a linear one compartment model.

Time Interval (hr)	Volume of Urine Excreted (ml)	Concentration in Urine (µg/ml)	<------>	<------>	<------>
0-1	91	805
1-2	99	539
2-4	206	324
4-6	194	181
6-9	no sample
9-12	577	16
12-24	1127	5

Answer

3. A given drug follows linear one compartment pharmacokinetics. If the values of kel and fe in patients with normal renal function are 0.45 hr-1 and 0.55, respectively, calculate the kel in a patient with 20 % of normal renal function. Assume that the non-renal rate processes do not change.

Answer