Evaluation of Once Daily Tobramycin Versus the Traditional Three Time Daily for the Treatment of Acute Pulmonary Exacerbations in Adult Cystic Fibrosis Patients

Abstract

Once daily tobramycin is convenient to use and achieves higher tissue levels that should kill Pseudomonas aeruginosa more rapidly. Small trials of OD compared with TDS aminoglycosides in CF patients have shown no dif-ference in efficacy or toxicity. No one has looked in detail at the impact on sputum microbiology. In a prospective, randomized study at Papworth Hospital, UK, we compared OD with TDS tobramycin, each plus a second anti-pseudomonal, for the treatment of acute infective exacer-bation in 15 adult cystic fibrosis patients colonized with Pseudomonas aeruginosa. Using the patients as their own control, the same individuals received the alternate treat-ment regime for the next exacerbation. We aimed to com-pare the clinical and bacteriological efficacy, toxicity>, and the effects on susceptibility of the organism among patients in both treatment groups. Isolates were identified, and the Minimum Inhibitory Concentration (MIC) of the antibi-otic in each patient was performed. Patients were assessed for clinical improvement, toxicity and the total viable count in their sputum on days 0\ 7 and 14. In both treatment groups there was a significant clinical improvement, and toxicity did not occur in either group. There was no differ-ence in clinical outcome, adverse events, or time to the next exacerbation. No difference was seen in the selection of antibiotic resistance. OD tobramycin appeared more ef-fective in reducing the number of bacteria in the group overall at day 7 and in two individuals, at day 14.