CICM SAQ 2015.2 Q19
Question
- a) Interpret the three pharmacodynamic (PD) profiles, labelled Scenario 1, Scenario 2 and Scenario 3, shown below.
- b) For each PD profile, describe how you would optimise the dose and/or frequency of antibiotic if prescribing:
- i) a beta lactam
- ii) an aminoglycoside
Answer
Answer and interpretation
a) Interpret the three pharmacodynamic (PD) profiles
Scenario 1
- Drug concentration does not reach MIC
- Ineffective dose
Scenario 2.
- Drug concentration is well above MIC
- Repeat dose maintains the concentration above MIC but increases the AUC: MIC ratio.
Scenario 3
- Peak drug concentration is well above MIC
- Significant period of interval between doses where drug level is below MIC
b) For each PD profile, describe how you would optimise the dose and/or frequency of antibiotic if prescribing:
Methods to optimise:
(i) Beta Lactam agents:
Scenario 1
- Increase dose
- More frequent dosing
- Consider continuous infusion after an appropriate loading dose
Scenario 2
- Decrease dose
- Less frequent dosing intervals
- Continuous infusion
Scenario 3
- More frequent dosing interval
- Continuous infusion
(ii) Aminoglycosides
Scenario 1
- Increase dose
Scenario 2
- Prolong dosing interval
- Therapeutic drug monitoring to avoid drug toxicity
Scenario 3
- No change
- Could consider higher dose
- Pass rate: 75%
- Highest mark: 8.0
Examination Library
CICM
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
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