Date: 5/24/95
Name: Allie's 95 cria
Signalment: Llama, Female, born 5/20/95, 29 pounds
History:Cria weak, FPT (plasma transfusion 5/23/95)
Current Status:improving
Dose:27.3 mg IV Dose Interval: 12 h
Time on Dose:since 5/22/95 at 8 PM
Serum Concentration #1: 5.0 mcg/mL @ 1 h #2: 0.9 mcg/mL @ 12 h
- Plot data from case on arithmetic graph paper
- make "y" axis 0 to 20 (mcg/mL serum)
- make "x" axis 0 to 14 (hours)
- Plot concentration #1 (5.0 mcg/mL @ 1 h)
- Plot concentration #2 (0.9 mcg/mL @ 12h )
- Is this the highest the concentration is likely to be (or have been) during this dose interval?
- Will the concentration go lower during this dose interval?
- Draw your idea of what might the "curve" look like if one had all the data?
- Does the concentration change much during the dose interval?
- What does this change indicate about the "rate of elimination" -- fast? slow?
Note contrast relative to phenobarbital.
- Is this a first time dose? Can one tell?
- How were sample times probably chosen?
- What fluid was measured? Why?
- The concentration is approximately 5 mcg/mL @ 1 hour, ... So what?
- The concentration is approximately 0.88 mcg/mL @ 12 hours, ... So what?
- How does the ratio of trough to peak compare to that in the phenobarbital example?
- Draw horizontal lines across graph at --
- 12 mcg/mL
- 5 mcg/mL
- 1 mcg/mL
- Write "often toxic" above the 12 mcg/mL line, the MTC
- Write "insufficient effect" below the 5 mcg/mL line, the MEC
- Write "need to drop below" below the 1 mcg/mL line, (another MTC?)
- Where is the therapeutic window in this graph?
- What is the meaning of the "need to drop below" statement
- How might his relate to toxicity of gentamicin
- Are these concentrations "absolute"?
- Note: this is the traditional understanding of ideal gentamicin dosage regimens.
New concepts will be presented in the chemotherapeutic section.
- Look at the observed concentrations in this case vis-a-vis the therapeutic window
- Note that the "cria" was said to be "improving" -- What does this mean for advising the
veterinarian?
- Should one change the dose and/or schedule for the Llama cria?
- Why or why not?
Send suggestions / questions
Last modified: 8/20/96 glc