From the Guidelines
Oral antibiotics should only be considered for septic arthritis after initial intravenous therapy and clinical improvement, with a suggested 3–4-week course of therapy. When selecting oral antibiotics, it is essential to consider the causative organism and its susceptibility pattern, as guided by the Infectious Diseases Society of America 1. For empiric oral therapy, options may include fluoroquinolones, clindamycin, or trimethoprim-sulfamethoxazole, with specific dosing regimens such as ciprofloxacin 500-750mg twice daily or levofloxacin 750mg once daily. In cases of methicillin-resistant Staphylococcus aureus (MRSA), linezolid or trimethoprim-sulfamethoxazole are preferred due to their efficacy against this pathogen 1.
Key considerations for transitioning to oral antibiotics include:
- Significant clinical improvement
- Afebrile status
- Good oral intake
- Reliable follow-up
- Adequate antibiotic concentrations achievable in synovial fluid with oral medications after initial reduction of infection burden with intravenous therapy and surgical drainage if indicated 1.
Monitoring for clinical improvement is crucial and should include:
- Decreased pain and swelling
- Improved range of motion
- Normalization of inflammatory markers like C-reactive protein and erythrocyte sedimentation rate 1.
The total duration of antibiotic therapy typically ranges from 2-6 weeks, depending on the causative organism, with longer courses for more virulent pathogens 1. Therapy should be tailored based on culture results and susceptibility testing to ensure the most effective treatment regimen.
From the FDA Drug Label
Clindamycin is indicated in the treatment of serious infections caused by susceptible anaerobic bacteria. Clindamycin is also indicated in the treatment of serious infections due to susceptible strains of streptococci, pneumococci, and staphylococci Serious skin and soft tissue infections; septicemia; Bacteriologic studies should be performed to determine the causative organisms and their susceptibility to clindamycin
The answer to the question of oral antibiotics for septic arthritis is clindamycin (PO), as it is indicated for the treatment of serious infections caused by susceptible bacteria, including those that can cause septic arthritis, such as streptococci and staphylococci 2.
- Key points:
- Clindamycin is effective against susceptible anaerobic bacteria, streptococci, pneumococci, and staphylococci.
- Bacteriologic studies should be performed to determine the causative organisms and their susceptibility to clindamycin.
From the Research
Oral Antibiotics for Septic Arthritis
- Oral antibiotics can be given in most cases of septic arthritis because they are not inferior to intravenous therapy 3
- The total duration of therapy ranges from two to six weeks; however, certain infections require longer courses 3
- Consideration for microorganisms such as Neisseria gonorrhoeae, Borrelia burgdorferi, and fungal infections should be based on history findings and laboratory results 3
- Amoxicillin/clavulanate can provide adequate antibiotic coverage as an empirical treatment for adult native joint septic arthritis 4
- Routine coverage of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa is not warranted but must be considered when specific risk factors are found 4
Treatment Approach
- Treatment of acute septic arthritis is initiated intravenously, but can be safely switched to oral after 2-4 days providing large doses of a well-absorbing antibiotic 5
- Empiric treatment should always cover Staphylococcus aureus and common respiratory pathogens 5
- The best choice of empiric antibiotics can be made by considering the patient's age, the synovial fluid gram stain results, and any preexisting conditions 6
Key Considerations
- Early diagnosis and treatment are essential to avoid irreversible joint destruction or death 7
- Drainage and effective antibiotic treatment are critical to avoid joint destruction and long-term impairment 4
- An episode of septic arthritis requires long-term follow up to check for relapses and to assess the outcome of any residual joint damage 6