What antibiotic regimen and duration is recommended for an otherwise healthy patient with a prosthetic joint infection (PJI) of the hip due to Staphylococcus epidermidis undergoing a 2-stage revision with an antibiotic spacer?

From the Guidelines

For an otherwise healthy patient with a prosthetic joint infection (PJI) of the hip due to Staphylococcus epidermidis undergoing a 2-stage revision with an antibiotic spacer, the recommended antibiotic regimen is 2 to 6 weeks of pathogen-specific intravenous antimicrobial therapy in combination with rifampin 300–450 mg orally twice daily, followed by rifampin plus a companion oral drug for a total of 3 months. The choice of companion oral drug should be based on in vitro susceptibility, allergies, intolerances, or potential intolerances, with recommended options including ciprofloxacin 1 or levofloxacin 1. Secondary companion drugs that can be used if necessary include co-trimoxazole, minocycline or doxycycline, first-generation cephalosporins, or antistaphylococcal penicillins 1.

Some key points to consider in the management of PJI due to Staphylococcus epidermidis include:

• The importance of susceptibility testing to guide antibiotic choice, as S. epidermidis can exhibit resistance to various antibiotics 1.
• The role of rifampin in combination with other antibiotics for the treatment of PJI, given its efficacy against staphylococcal biofilms 1.
• The need for careful monitoring of patients receiving outpatient intravenous antimicrobial therapy, following published guidelines 1.
• The potential for indefinite chronic oral antimicrobial suppression in selected cases, although this should be decided on an individual basis, taking into account factors such as the patient's ability to use rifampin, potential for progressive implant loosening, and hazards of prolonged antibiotic therapy 1.

In terms of specific antibiotic regimens, the initial 2 to 6 weeks of intravenous therapy can be followed by oral antibiotics, with the total duration of therapy typically being around 3 months 1. The choice of antibiotics should be tailored to the individual patient's needs and susceptibility results, with the goal of eradicating the infection and preventing recurrence.

From the Research

Antibiotic Regimen for Prosthetic Joint Infection

The recommended antibiotic regimen for an otherwise healthy patient with a prosthetic joint infection (PJI) of the hip due to Staphylococcus epidermidis undergoing a 2-stage revision with an antibiotic spacer is as follows:

• The use of a combination therapy of oral rifampin plus continuous infusion of fosfomycin has been reported to be effective in treating methicillin-resistant Staphylococcus epidermidis prosthetic infection 2.
• Antibiotic-loaded spacers may improve antimicrobial efficacy in two-stage revision of prosthetic joint infections, but they may also interfere in the course of infection 3.
• The choice of antibiotics should be based on the susceptibility of the isolated pathogen, and the use of vancomycin, gentamicin, and aztreonam has been reported in the literature 3, 4.

Duration of Antibiotic Treatment

The duration of antibiotic treatment for PJI of the hip due to Staphylococcus epidermidis is not well established, but the following guidelines can be considered:

• The use of prolonged treatment with linezolid and rifampicin has been reported to be effective in treating complicated prosthetic joint infections caused by vancomycin-resistant Staphylococcus epidermidis 5.
• The treatment duration should be individualized based on the patient's response to treatment and the presence of any complications or comorbidities.
• The use of antibiotic-loaded spacers for 4 months, followed by removal and definitive total joint arthroplasty, has been reported in the literature 2.

Considerations for Antibiotic Resistance

The following considerations should be taken into account when selecting an antibiotic regimen for PJI of the hip due to Staphylococcus epidermidis:

• Staphylococcus epidermidis strains causing PJIs often show multiresistance, including resistance to rifampicin, which is mainly caused by one or two single-nucleotide polymorphisms (SNPs) 6.
• The detection of the mecA gene is necessary before initiating treatment of infections due to Staphylococcus epidermidis when it displays intermediate susceptibility to cefoxitin 6.
• The use of newer antimicrobial agents, such as tigecycline, linezolid, and daptomycin, may provide alternatives for monotherapy or combination therapy with rifampicin 6.