Tobramycin pharmacokinetics in patients with cystic fibrosis before and after bilateral lung transplantation

Cystic fibrosis foundation consensus statements for the care of cystic fibrosis lung transplant recipients

Cystic fibrosis (CF) is the indication for transplantation in approximately 15% of recipients worldwide, and Cystic Fibrosis Lung Transplant Recipients (CFLTRs) have excellent long-term outcomes. Yet, CFLTRs have unique comorbidities that require specialized care. The objective of this document is to provide recommendations to CF and lung transplant clinicians for the management of perioperative and underlying comorbidities of CFLTRs and the impact of transplantation on these comorbidities. The Cystic Fibrosis Foundation (CFF) organized a multidisciplinary committee to develop CF Lung Transplant Clinical Care Recommendations. Three workgroups were formed to develop focused questions. Following a literature search, consensus recommendations were developed by the committee members based on literature review, committee experience and iterative revisions, and in response to public comment. The committee formulated 32 recommendation statements in the topics related to infectious disease, endocrine, gastroenterology, pharmacology, mental health and family planning. Broadly, the committee recommends close coordination of care between the lung transplant team, the cystic fibrosis care center, and specialists in other disciplines with experience in the care of CF and lung transplant recipients. These consensus statements will help lung transplant providers care for CFLTRs in order to improve post-transplant outcomes in this population.

Pharmacokinetic and Pharmacodynamic Optimization of Antibiotic Therapy in Cystic Fibrosis Patients: Current Evidences, Gaps in Knowledge and Future Directions

Antibiotic therapy is one of the main treatments for cystic fibrosis (CF). It aims to eradicate bacteria during early infection, calms down the inflammatory process, and leads to symptom resolution of pulmonary exacerbations. CF can modify both the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of antibiotics, therefore specific PK/PD endpoints should be determined in the context of CF. Currently available data suggest that optimal PK/PD targets cannot be attained in sputum with intravenous aminoglycosides. Continuous infusion appears preferable for β-lactam antibiotics, but optimal concentrations in sputum are unlikely to be reached, with some possible exceptions such as meropenem and ceftolozane. Usual doses are likely suboptimal for fluoroquinolones and linezolid, whereas daily doses of 45-60 mg/kg and 200 mg could be convenient for vancomycin and doxycycline, respectively. Weekly azithromycin doses of 22-30 mg/kg could also be appropriate for its anti-inflammatory effect. The difficulty with achieving optimal concentrations supports the use of combined treatments and the inhaled administration route, as very high local concentrations, concomitantly with low systemic exposure, can be obtained with the inhaled route for aminoglycosides, colistin, and fluoroquinolones, thus minimizing the risk of toxicity.

Comparison of Vancomycin Pharmacokinetics in Cystic Fibrosis Patients Pre and Post-lung Transplant

Background:

Vancomycin is commonly used to treat acute cystic fibrosis (CF) exacerbations associated with methicillin-resistant Staphylococcus aureus (MRSA). Multiple studies have demonstrated pharmacokinetic differences of antimicrobials in the CF population. Very little data exist regarding pharmacokinetics postlung transplant, but 2 studies have noted changes in tobramycin pharmacokinetics. No such studies exist evaluating vancomycin in CF patients postlung transplant.

Methods:

A retrospective cohort review of CF patients who underwent lung transplantation and received vancomycin pre- and posttransplant was conducted. CF patients who underwent transplant between 2007 and 2016 at 4 medical centers throughout the United States were included. The primary endpoint was the change in elimination rate constant. The secondary endpoints were subgroup analyses of patients grouped by age, time posttransplant, and number of nephrotoxic medications.

Results:

A total of 25 patients were included, of which just under half were pediatric. Patients were significantly older and heavier posttransplant and had higher serum creatinine and number of nephrotoxic medications. The change in elimination rate constant from pre- to posttransplant was −0.50 hr⁻¹ which was statistically significant (P < .001). This significant decrease was consistent among all subgroups of patients evaluated with the exception of pediatric patients.

Conclusion:

Vancomycin pharmacokinetics are significantly altered in CF patients in the posttransplant setting as evidenced by a decrease in elimination rate constant. This decrease may be related to a decrease in renal clearance and higher numbers of nephrotoxic medications posttransplant. Regardless, pretransplant vancomycin regimens may not predict appropriate posttransplant regimens.

Sedation with Propofol for Bronchoscopy in Cystic Fibrosis Lung Transplant Recipients

INTRODUCTION

Flexible fiberoptic bronchoscopy (FFB) plays an important role in the surveillance of cystic fibrosis (CF) patients after lung transplantation (LTx). With rapid onset and clearance, propofol provides a safe and efficient method for sedation during FFB, yet sedation requirements for CF patients are not well described.

OBJECTIVES

Due to pharmacokinetic differences for other classes of drugs in CF patients, this study was performed to examine propofol requirements for sedation during bronchoscopy in lung transplant recipients with CF.

METHODS

A single-center retrospective cohort study was performed to examine propofol sedation requirements during outpatient surveillance. FFB procedures with transbronchial biopsy (TBB) in post-LTx recipients between 2009 and 2014 were conducted.

RESULTS

A total of 40 FFB procedures with TBB were performed 20 CF (11 females), 20 non-CF (11 females). Mean (± SD) age was 25.6 ± 9.2 (range 13-42) years and 22.2 ± 10.8 (range 11-39) years for the CF and non-CF groups, respectively. Propofol requirements were significantly higher in the CF patients compared to the non-CF patients. Mean (± SD) propofol dose for CF patients was 334 ± 86 versus 214 ± 88 mg for non-CF patients (p < 0.001). Mean (± SD) propofol dose per weight (mg/kg) was 6.5 ± 2.1 for CF patients versus 3.8 ± 1.6 for non-CF patients (p < 0.001).

CONCLUSIONS

Compared to a non-CF cohort, CF lung transplant recipients required higher dosages of propofol for sedation during FFB with TBB.