Austyn Grim, PGY2

Children's Hospital of Philadelphia, Langhorne, Pennsylvania

Objectives: 

Review the current literature of tobramycin dosing in cystic fibrosis patients.
Analyze tobramycin population pharmacokinetic parameters in cystic fibrosis patients less than five years of age.

Abstract:

Introduction:
Cystic fibrosis patients experience pulmonary exacerbations which result in a decline of lung function and altered airway defenses. Ultimately, pulmonary colonization with Pseudomonas aeruginosa has been associated with earlier mortality. Patients receive anti-pseudomonal antibiotic therapies in attempts to eradication and treat this organism. Antibiotic combinations that include aminoglycosides are utilized for the treatment of cystic fibrosis exacerbations. Due to pharmacokinetic differences in cystic fibrosis patients, antibiotic dosing regimens may require alteration to account for the increased renal elimination and increased volume of distribution. For aminoglycosides, such as tobramycin, the Cystic Fibrosis Foundation recommends once daily (extended interval) dosing over three times daily dosing, to optimize maximum concentrations and hypothetically lessen toxicity. Literature supports the use of once daily tobramycin dosing in cystic fibrosis patients greater than five years of age. Currently, little literature has been published to support the use and to determine an appropriate starting dose of once daily tobramycin in cystic fibrosis patients less than five years of age.
Methods:
Cystic fibrosis patients less than five years of age who received tobramycin intravenously between March 1, 2011 and September 1, 2018 were included in this review. Medical records were reviewed for tobramycin dosing regimens, tobramycin serum levels, and serum creatinine levels. A population pharmacokinetic model was developed using NONMEM software. The feasibility and appropriate initial dose of an extended interval tobramycin dosing regimen was determined through population pharmacokinetic modeling with simulation patients.
Results:
Results will be submitted within final slides.
Conclusion:
Conclusion will be submitted within final slides.

Handout Slides:

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