Cefadroxil kinetics and dynamics in a pediatric patient with acute osteomyelitis
M C Nahata1, D S Jackson, D A Powell
1College of Pharmacy, Ohio State University, Columbus.
Insights
Cefadroxil pharmacokinetics and pharmacodynamics were evaluated in a pediatric osteomyelitis case. The study found suboptimal drug levels and bactericidal titers, leading to treatment failure and highlighting the need for revised cefadroxil dosing regimens.
Area of Science:
- Pharmacology
- Pediatric Infectious Diseases
- Clinical Pharmacy
Background:
- Cefadroxil is used for acute osteomyelitis, but its pharmacokinetic and pharmacodynamic properties in this context are not well-established.
- Osteomyelitis in children requires effective antimicrobial therapy with optimized drug delivery.
Purpose of the Study:
- To evaluate the pharmacokinetics and pharmacodynamics of cefadroxil in a pediatric patient with Staphylococcus aureus osteomyelitis.
- To correlate drug levels and bactericidal activity with clinical outcomes.
Main Methods:
- A pediatric patient with osteomyelitis received oral cefadroxil (60 mg/kg every 12 h) after initial treatment with intravenous nafcillin.
- Serum cefadroxil concentrations were measured using HPLC, and serum bactericidal titers were determined at various time points.
- Pharmacokinetic parameters including peak and trough concentrations, oral clearance, and elimination half-life were calculated.
Main Results:
- The patient exhibited low peak (35.4 µg/ml) and trough (0.5 µg/ml) serum cefadroxil concentrations.
- Elimination half-life was 2.4 hours with an oral clearance of 11.5 ml/min/kg.
- Peak and trough bactericidal titers (1:4 and <1:2, respectively) were below the recommended levels (≥1:8 and ≥1:2) for therapeutic success, correlating with clinical worsening.
Conclusions:
- The observed cefadroxil pharmacokinetic and pharmacodynamic profile in this pediatric patient was inadequate for treating Staphylococcus aureus osteomyelitis.
- Therapeutic failure was linked to sub-optimal drug concentrations and insufficient bactericidal activity.
- Future studies should investigate alternative cefadroxil dosage regimens for pediatric osteomyelitis.
Abstract:
Cefadroxil has been used for the treatment of acute osteomyelitis. However, its pharmacokinetics and pharmacodynamics have not been studied in these patients. We evaluated the kinetics and dynamics of cefadroxil in a pediatric patient with osteomyelitis caused by Staphylococcus aureus. After initial clinical improvement on intravenous nafcillin, the patient received oral cefadroxil, 60 mg/kg every 12 h. Blood samples were collected at 0, 1, 2, 4, 6, 8 and 12 h; bactericidal titers were determined at 2 and 12 h. Cefadroxil was measured by an HPLC method. The peak and trough serum concentration of cefadroxil was 35.4 and 0.5 micrograms/ml, respectively. The oral clearance and elimination half-life were 11.5 ml/min/kg and 2.4 h, respectively. The peak bactericidal titer was 1:4 and the trough titer was less than 1:2 for the infecting organism. The child's finger appeared worse with an increase in swelling and erythema after 2 days of cefadroxil therapy. Cefadroxil was discontinued and the patient was treated successfully with intravenous nafcillin. The apparent failure of cefadroxil therapy can be explained by lower than recommended peak (greater than or equal to 1:8) and trough (greater than or equal to 1:2) titers for therapeutic success. Thus, an alternative dosage regimen of cefadroxil should be considered in the future studies.
More Related Videos
Related Concept Videos
01:15Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations
01:20Estimation of k and VD of Aminoglycosides
01:23Pharmacokinetics in Pediatric Patients: Overview and Drug Absorption
01:17Pharmacokinetics in Pediatric Patients: Drug Distribution
01:24Pharmacokinetics in Pediatric Patients: Drug Metabolism
01:26Pharmacokinetics in Pediatric Patients: Drug Excretion