Study Compares Oral and Intravenous Antibiotics for P. aeruginosa Infections in People With CF

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

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P. aeruginosa infections

Oral antibiotics are just as effective as intravenous (into-the-vein) antibiotics at killing Pseudomonas aeruginosa bacteria in people with cystic fibrosis (CF), a new study shows.

This finding may allow people with CF to spend less time in the hospital to receive treatment, ultimately reducing treatment burden.

The study, “Intravenous versus oral antibiotics for eradication of Pseudomonas aeruginosa in cystic fibrosis (TORPEDO-CF): a randomised controlled trial,” was published in The Lancet Respiratory Medicine.

Pseudomonas aeruginosa is a type of bacteria that commonly causes problematic lung infections in people with CF. It is estimated that most people with CF develop chronic P. aeruginosa infections.

Current guidelines suggest that, in order to prevent such chronic infections from developing, it is important to administer bacteria-killing antibiotics as soon as a P. aeruginosa infection is detected.

There are multiple types of antibiotics, with different routes of administration, including oral and intravenous. However, it not clear whether certain regimens are more or less effective than others.

In the new study, a team led by researchers from the University of Nottingham and University Hospitals Bristol and Weston NHS Foundation Trust (UHBW), in the U.K., reported results from TORPEDO-CF (ISRCTN02734162), a trial designed to compare oral vs. intravenous antibiotic treatment.

The trial enrolled 286 people with CF newly diagnosed with P. aeruginosa infections. Most (95%) participants were children between the ages of 28 days and 17 years.

Participants were divided randomly into two groups: one group (137 participants) was treated with intravenous antibiotics for 14 days; while the other group (149 participants) was given oral antibiotics.

Intravenous treatment was based on 50 mg/kg ceftazidime three times daily and 10 mg/kg tobramycin once daily. Oral treatment was based on 20 mg/kg ciprofloxacin twice daily. All participants also were given an inhaled antibiotic (colistimethate) for 12 weeks.The study’s primary goal was eradication of P. aeruginosa bacteria at three months and remaining free of infection up to 15 months.Of the participants with data available, a similar proportion in both groups experienced eradication of P. aeruginosa infection after three months of treatment, remaining free of the bacteria through 15 months — 55 of 125 (44%) participants in the intravenous group and 68 out of 130 (52%) in the oral group.

Further analyses did not indicate statistically significant differences between the groups in terms of bacterial clearance. There also was no evidence for significant differences in terms of exacerbations, changes in lung function, or quality of life.

Just fewer than half the participants in both groups reported at least one non-serious adverse event (side effect); the most common were cough and upper respiratory tract infection. Serious adverse events were reported by 8% of participants in both groups. One severe adverse event (a cancer) was reported, but deemed unlikely to be related to the studied treatments. No participants died or had any unexpected serious adverse reactions.

One advantage of oral antibiotics is that they do not require hospital admission for treatment administration as intravenous antibiotics typically do.

“Our study found that traditional oral antibiotics are just as effective as intravenous antibiotics, which means that CF patients who have a new Pseudomonas aeruginosa can be treated at home and saved the inconvenience of having to be admitted to hospital for treatment,” Simon Langton Hewer, MD, consultant respiratory pediatrician at University Hospitals Bristol and the study’s co-author, said in a press release.

The researchers also performed an economic analysis, which suggested that oral treatment was generally less costly than intravenous treatment — by an average of roughly £5,939 (about $7,700) per patient. Further models indicated that oral treatments also led to a greater increase in quality-adjusted life years, suggesting greater cost-effectiveness, though the difference was not statistically significant.

“Compared with oral therapy, intravenous antibiotics did not achieve sustained eradication of P. aeruginosa in a greater proportion of patients with cystic fibrosis and was more expensive,” the researchers wrote.

“For many years we felt we should admit children with cystic fibrosis for intravenous antibiotics when they first had a Pseudomonas infection. This can be upsetting for the child and their family and can disrupt school and family life,” said Alan Smyth, MD, the study’s co-author.

“Thanks to the TORPEDO trial, we now know that oral and inhaled treatment is at least as effective as intravenous, in most cases. In future, we can give this treatment at home and avoid the inconvenience and expense of a hospital admission,” Smyth said.