American College of Physicians: Internal Medicine — Doctors for Adults ®

Advertisement

The MKSAP Challenge

From the May ACP Observer, copyright 2005 by the American College of Physicians.

Clinical scenario

Two years after undergoing mitral valve replacement, a 48-year-old man has a cerebrovascular accident

Two years after undergoing mitral valve replacement, a 48-year-old man has a cerebrovascular accident. Except for fever, general physical examination is noncontributory.

The cardiac examination is unchanged from previous findings. A transesophageal echocardiogram shows an oscillating mass on the mitral valve but no evidence of perivalvular extension or abscess. Six sets of blood cultures grow Enterococcus faecalis, which is resistant to penicillin and ampicillin but sensitive to vancomycin. The laboratory also reports the absence of high-level resistance to gentamicin and streptomycin.

A decision is made to treat medically, and the patient is begun on vancomycin, 1 g intravenously every 12 hours, and gentamicin, 80 mg intravenously every eight hours (the patient weighs 76 kg [167 lb]). After three days of therapy, the laboratory reports that his vancomycin peak level is 32 g/mL with a trough level of 9 g/mL, and his gentamicin peak level is 3.2 g/mL with a trough level of 0.8 g/mL. The technician notes that the vancomycin peak and trough levels and the gentamicin trough level are in the desirable range but that the laboratory's therapeutic peak range for gentamicin is 4 to 8 g/mL. Repeat blood cultures show no growth, and complete blood count and serum creatinine values are normal.

Which of the following is most appropriate at this time?

A. Increase the gentamicin dose; keep the vancomycin unchanged
B. Decrease the interval between the gentamicin doses; keep the vancomycin unchanged
C. Keep both the gentamicin and the vancomycin doses unchanged
D. Increase the vancomycin dose; keep the gentamicin unchanged

Answer

Top

This is a printer-friendly version of this page

Print this page  |  Close the preview

Share

 
 

Internist Archives Quick Links

Have questions about the new ABIM MOC Program?

Have questions about the new ABIM MOC Program?

ACP explains the ABIM requirements and offers many free solutions to earn MOC points.

One Click to Confidence - Free to members

One Click to Confidence - Free to members ACP Smart Medicine is a new, online clinical decision support tool specifically for internal medicine. Get rapid point-of-care access to evidence-based clinical recommendations and guidelines. Plus, users can easily earn CME credit. Learn more