Changes in gentamicin pharmacokinetic profiles induced by mechanical ventilation
C Triginer1, I Izquierdo, R Fernández
1Intensive Care Unit Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain.
European Journal of Clinical Pharmacology
|January 1, 1991
Summary
Controlled mechanical ventilation (CMV) increases gentamicin
Area of Science:
- Pharmacology
- Critical Care Medicine
- Nephrology
Background:
- Gentamicin is an antibiotic commonly used in post-cardiac surgery patients.
- Controlled mechanical ventilation (CMV) is frequently required in these patients.
- The impact of CMV on gentamicin pharmacokinetics is not fully understood.
Purpose of the Study:
- To investigate the influence of CMV on gentamicin's pharmacokinetic profile.
- To compare gentamicin levels during CMV versus spontaneous breathing (SB).
Main Methods:
- A parallel study design was used in 23 post-open heart surgery patients.
- Patients were divided into two groups based on CMV duration.
- Pharmacokinetic parameters including volume of distribution (VZ), half-life (t1/2), and plasma levels (Cmax, Cmin) were measured.
Main Results:
- Patients on CMV showed a significantly increased VZ (0.36 vs. 0.25 L/kg) and t1/2 (3.63 vs. 2.90 h).
- Peak gentamicin levels (Cmax) were lower during CMV (4.30 vs. 5.53 µg/mL), falling below the therapeutic range.
- Trough levels (Cmin) and total clearance (CL) did not differ significantly.
Conclusions:
- CMV alters gentamicin pharmacokinetics, increasing its volume of distribution.
- This can lead to sub-therapeutic peak concentrations, necessitating higher gentamicin doses in ventilated patients.
- Consider higher gentamicin dosing in patients receiving CMV, even prior to therapeutic drug monitoring.
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