Usage and monitoring of intravenous tobramycin in cystic fibrosis in Australia and the UK

Abstract

AbstractAim: To characterise usage and monitoring of intravenous tobramycin in cystic fibrosis (CF) patients in Australia and the UK.Methods: An anonymous, online survey of healthcare professionals caring for CF patients was conducted. Survey questions were designed to obtain information on tobramycin dosing, therapeutic drug monitoring and toxicity monitoring.Results: The survey was sent to pharmacists and clinicians in 73 CF centres. Responses were received from 32 and 40 healthcare professionals, from Australia and the UK, respectively. Once‐daily dosing of tobramycin was the preferred administration regimen for 93.8 and 67.5% of participants in Australia and the UK, respectively. Among them 68.8% of Australian and 55% of UK participants initiated tobramycin therapy at a dose of 10 mg/kg/day or greater. Australian participants most commonly adjusted tobramycin dosage using log‐linear regression analysis (40.6%) or trough measurements (28.1%). UK participants most commonly adjusted tobramycin dosage using trough (55%) or peak and trough measurements (37.5%). In 90.6% of Australian and 95% of UK participants practices, serum creatinine was routinely monitored during admission. Standard pure tone audiometry was performed by 15.6% of Australian and 17.5% of UK participants and high‐frequency pure tone audiometry was performed by 15.6% of Australian and 10% of UK participants, once or twice a year.Conclusions: Many discrepancies exist between Australia and the UK and within each country with respect to monitoring of intravenous tobramycin in CF patients. Greater ototoxicity monitoring is likely necessary in both countries. Further education of health professionals about the existence of national guidelines and guidance on how they can be applied in practice is likely required.