Aminoglycoside Pharmacokinetics and Pharmacodynamics

Non Steady State Dosing

Questions provided by Michele Splinter, Pharm.D.

You are asked to revise dosing tobramycin therapy in a pulmonary patient who has pneumonia secondary to Klebsiella pneumoniae. The patient is also receiving ceftazidime 2 g every 8 hours.

**Patient characteristics**
Age: 57 yr	Gender: female	Weight: 64.5 kg	ht: 69 in
Scr: 2.23 mg/dL	Organism MIC 0.5 mg/L

Based on the following doses and serum concentrations, calculate the following: kel, t_1/2, Vd, CL, infusion dose (down to the nearest 10 mg) over 1 hr, dosing interval (up to the nearest 12 hr), projected Cp_max^ss and Cp_min^ss with target Cp_max^ss = 8 mg/L and Cp_min^ss = less than 1 mg/L.

The Data
Date Time Dosage Infusion Duration Serum Concentration

09/17/15 2200 300 mg 1 hr

09/18/15 1000 300 mg 1 hr

09/18/15 2200 300 mg 1 hr

09/19/15 0930 3.81 mg/L

09/19/15 1000 300 mg 1 hr

09/19/15 1225 11.02 mg/L

09/19/15 2150 4.31 mg/L

**The Data**
Date	Time	Dosage	Infusion Duration	Serum Concentration
09/17/15	2200	300 mg	1 hr
09/18/15	1000	300 mg	1 hr
09/18/15	2200	300 mg	1 hr
09/19/15	0930			3.81 mg/L
09/19/15	1000	300 mg	1 hr
09/19/15	1225			11.02 mg/L
09/19/15	2150			4.31 mg/L

NOTE: Clicking the button above
will prevent you getting credit for this problem

To get credit for this problem print this page, work the problem and

You will have one chance to submit your answers for this problem [# 1140812374]. You can try the homework problem more than once with different data to improve your grade. Your highest score is recorded. After submitting your answers you can use the browser back arrow to get back here and see how the compuer worked the problem.

Some Equations:

Equation 27.4.1 IBW for Male Patients

Equation 27.4.2 IBW for Female Patients

Creatine Clearance C-G Equation
Equation 27.4.3 Creatinine Clearance (Cockcroft-Gault Equation)

Equation 27.4.4 Apparent Volume of Distribution, Vd

Equation 27.4.5 Dosing Interval, τ

Equation 27.4.6 Loading Dose

Equation 27.4.7 Maintenance Dose

Last update: Mon 26 Jun 2017 08:28:30 pm