Background: People with cystic fibrosis are susceptible to pulmonary infection with Pseudomonas aeruginosa. This may become chronic and lead to increased mortality and morbidity. If treatment is commenced promptly, infection may be eradicated through prolonged antibiotic treatment.
Objective: To compare the clinical effectiveness, cost-effectiveness and safety of two eradication regimens.
Design: This was a Phase IV, multicentre, parallel-group, randomised controlled trial.
Setting: Seventy UK and two Italian cystic fibrosis centres.
Participants: Participants were individuals with cystic fibrosis aged > 28 days old who had never had a P. aeruginosa infection or who had been infection free for 1 year.
Interventions: Fourteen days of intravenous ceftazidime and tobramycin or 3 months of oral ciprofloxacin. Inhaled colistimethate sodium was included in both regimens over 3 months. Consenting patients were randomly allocated to either treatment arm in a 1 : 1 ratio using simple block randomisation with random variable block length.
Main outcome measures: The primary outcome was eradication of P. aeruginosa at 3 months and remaining free of infection to 15 months. Secondary outcomes included time to reoccurrence, spirometry, anthropometrics, pulmonary exacerbations and hospitalisations. Primary analysis used intention to treat (powered for superiority). Safety analysis included patients who had received at least one dose of any of the study drugs. Cost-effectiveness analysis explored the cost per successful eradication and the cost per quality-adjusted life-year.
Results: Between 5 October 2010 and 27 January 2017, 286 patients were randomised: 137 patients to intravenous antibiotics and 149 patients to oral antibiotics. The numbers of participants achieving the primary outcome were 55 out of 125 (44%) in the intravenous group and 68 out of 130 (52%) in the oral group. Participants randomised to the intravenous group were less likely to achieve the primary outcome; although the difference between groups was not statistically significant, the clinically important difference that the trial aimed to detect was not contained within the confidence interval (relative risk 0.84, 95% confidence interval 0.65 to 1.09; p = 0.184). Significantly fewer patients in the intravenous group (40/129, 31%) than in the oral group (61/136, 44.9%) were hospitalised in the 12 months following eradication treatment (relative risk 0.69, 95% confidence interval 0.5 to 0.95; p = 0.02). There were no clinically important differences in other secondary outcomes. There were 32 serious adverse events in 24 participants [intravenous: 10/126 (7.9%); oral: 14/146 (9.6%)]. Oral therapy led to reductions in costs compared with intravenous therapy (-£5938.50, 95% confidence interval -£7190.30 to -£4686.70). Intravenous therapy usually necessitated hospital admission, which accounted for a large part of this cost.
Limitations: Only 15 out of the 286 participants recruited were adults - partly because of the smaller number of adult centres participating in the trial. The possibility that the trial participants may be different from the rest of the cystic fibrosis population and may have had a better clinical status, and so be more likely to agree to the uncertainty of trial participation, cannot be ruled out.
Conclusions: Intravenous antibiotics did not achieve sustained eradication of P. aeruginosa in a greater proportion of cystic fibrosis patients. Although there were fewer hospitalisations in the intravenous group during follow-up, this confers no advantage over the oral therapy group, as intravenous eradication frequently requires hospitalisation. These results do not support the use of intravenous antibiotics to eradicate P. aeruginosa in cystic fibrosis.
Future work: Future research studies should combine long-term follow-up with regimens to reduce reoccurrence after eradication.
Trial registration: Current Controlled Trials ISRCTN02734162 and EudraCT 2009-012575-10.
Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 65. See the NIHR Journals Library website for further project information.
Keywords: CYSTIC FIBROSIS; ERADICATION; INTRAVENOUS THERAPY; ORAL THERAPY; PSEUDOMONAS AERUGINOSA; RANDOMISED CONTROLLED TRIAL.
Cystic fibrosis is a genetic condition that affects mucous glands, causing sticky mucus in the lungs and digestive system. People with cystic fibrosis are prone to lung infection with a bacterium called Pseudomonas aeruginosa, which can lead to serious long-term complications and death. It is possible to eradicate P. aeruginosa if antibiotics are started promptly and taken for several months. The Trial of Optimal TheRapy for Pseudomonas EraDicatiOn in Cystic Fibrosis (TORPEDO-CF) was designed to find out if intravenous ceftazidime and tobramycin were better at eradicating P. aeruginosa than oral ciprofloxacin. A total of 286 children, young people and adults with cystic fibrosis joined the study from 70 UK and two Italian centres. Approximately half of the participants received treatment with intravenous antibiotics and half with oral antibiotics. All participants received inhaled colistin for 3 months and were followed up for a minimum of 15 months. We studied whether or not either treatment eradicated P. aeruginosa, and if reinfection happened during follow-up. We also collected data on lung function, other chest infections and hospital admissions, and examined whether or not one treatment was more cost-effective than the other. In total, 15 adults joined TORPEDO-CF, so the study population may not totally match the wider cystic fibrosis population; however, in TORPEDO-CF, we found that intravenous antibiotics did not achieve persistent eradication of P. aeruginosa in a greater proportion of cystic fibrosis patients. We also found that oral antibiotics were more cost-effective than intravenous antibiotics. The intravenous antibiotics group had fewer hospital admissions during follow-up, but, as they were usually admitted for their initial treatment, this was not considered an advantage over the oral antibiotics group. The TORPEDO-CF results do not support the use of intravenous antibiotics to eradicate P. aeruginosa in cystic fibrosis and, when the findings of this trial are applied in routine clinical practice in the NHS, patients will most likely receive oral treatment as an outpatient, avoiding the need for hospital admission.