Two weeks of antibiotic therapy was as effective as 4 weeks for septic arthritis, a prospective single-center study found.
Among 77 patients randomized to a 4-week course of therapy following surgical drainage for native joint bacterial arthritis, the rate of complete microbiological remission after at least 2 months of follow-up was 97%, according to Ilker Uçkay, MD, of Uniklinik Balgrist in Zurich, Switzerland, and colleagues.
And among an equivalent number of patients receiving a 2-week course of antibiotics, the remission rate was 99%, signaling noninferiority of the shorter regimen (P=0.56), the investigators reported online in Annals of the Rheumatic Diseases.
"In the current era of critical shortages of effective antibiotics, antimicrobial stewardship principles suggest that a shorter treatment duration and early switch to targeted oral agents could decrease antibiotic-related adverse events, costs, and possibly emergence of antimicrobial resistance," the team wrote.
The longstanding recommendation for managing septic arthritis has been 3 to 6 weeks of treatment with antibiotics, with most clinicians prescribing the treatment for 4 weeks in adults. However, that recommendation was based on clinical experience and expert opinion, and recent data have suggested that 2 weeks may suffice, particularly for infections of the hand joints.
Therefore, to test the hypothesis that a shorter course of treatment would be effective and safe, Uçkay and colleagues enrolled 154 hospitalized adults from 2015 to 2018 who had undergone articular lavage for bacterial arthritis.
Choices about initial empiric antibiotic regimen and timing of switching from parenteral to oral therapy were at the discretion of the treating clinicians.
Patients' median age was 51, and 38% were women. A total of 10% of patients had immune-compromising comorbidities such as diabetes. The infections were a result of cat bites and scratches, dog bites, human bites, intravenous drug abuse, and surgical site complications.
The affected sites most commonly were the fingers, metatarsal joints, and knees, and Staphylococcus aureus was the most frequently identified pathogen.
There were 13 different initial intravenous regimens, with the most common agents being co-amoxiclav (amoxicillin/clavulanic acid), vancomycin, and ceftriaxone. In three cases, the full course was intravenous, while in 32, only oral treatment was given.
The most commonly used oral agents were co-amoxiclav, quinolones, and clindamycin.
The median duration of intravenous therapy was 1 day in the 2-week group and 2 days in the 4-week group (P=0.01), while median length of hospital stay was 4 days in the 2-week group and 6 days in the 4-week group (P=0.01). Time spent on sick leave was 28 days in the 2-week group and 36 days in the 4-week group.
A total of six patients had treatment failures, but in three of these, the recurrence was associated with completely different pathogens. Therefore, true recurrences were seen in only three patients, with the implicated pathogens being S. aureus in two cases and Streptococcus pyogenes in one.
There also were no differences between the two groups in adverse events or sequelae. Adverse events related to antibiotic treatment were reported in 3% of the 2-week group and 6% of the 4-week group, and included superficial fungal infections and allergic rashes. There were no cases of Clostridium difficile colitis.
Mechanical or neurologic sequelae were observed in 47% of the 2-week group and 54% of the 4-week group, which included stiffness and flexion incapacity or contractions.
Because the site of infection was the hand and wrist in the majority of cases, the investigators also conducted a subgroup analysis of these patients, finding similar results as in the main analysis. The joints affected most often were the index finger, middle finger, and thumb, and the most commonly used antibiotics were co-amoxiclav, levofloxacin, and clindamycin. Recurrences were seen in one patient in the 2-week group and two in the 4-week group.
"The results of our trial also support our longstanding policy of providing only a short duration of initial parenteral antibiotic therapy for bacterial arthritis. This contrasts with widespread suggestions for several weeks of parenteral therapy for adult septic arthritis," the authors stated.
"We hope that these recent prospective data ... may make a start in revising that view, at least with hand bacterial arthritis," the researchers wrote. Furthermore, shortening the interval between parenteral and oral therapy "could help reduce financial costs, length of hospital stay, and potentially intravenous line-related complications."
A limitation of the study, the team said, was its single-center design.
Disclosures
The authors reported no financial conflicts.
Primary Source
Annals of the Rheumatic Diseases
Source Reference: Gjika E, et al "Two weeks versus four weeks of antibiotic therapy after surgical drainage for native joint bacterial arthritis: a prospective, randomized, non-inferiority trial" Ann Rheum Dis 2019; doi:10.1136/annrheumdis-2019-215116.