What is the appropriate management plan for a patient with a history of leukopenia and a prosthetic joint infection caused by GBS, currently being treated with cephalexin?

From the Guidelines

For a patient with leukopenia and a prosthetic joint infection caused by Group B Streptococcus (GBS) currently on cephalexin, the recommended management plan should include switching to a more effective antibiotic regimen and considering surgical intervention. The patient's current antibiotic regimen with cephalexin may not be sufficient for prosthetic joint infections, which often require more aggressive therapy. Given the patient's history of leukopenia with penicillin, close monitoring of white blood cell counts is essential. The most recent and highest quality study 1 suggests that the optimal aims of therapy for prosthetic joint infection are to eradicate the infection and maintain function of the joint and quality of life for the patient. Surgical options for management of prosthetic joint infection include debridement and implant retention (DAIR), prosthesis exchange, prosthesis resection, or amputation. Antimicrobial therapy is administered concurrently with these surgical approaches, and the choice of antibiotic should be based on the susceptibility pattern of the infecting organism. In this case, since the GBS isolate is resistant to erythromycin, clindamycin, and tetracycline, alternative antibiotics such as penicillin G or ampicillin may be considered. However, given the patient's history of leukopenia with penicillin, alternatives such as clindamycin or vancomycin may be more suitable. Regular follow-up with both infectious disease and orthopedic specialists is crucial to monitor treatment response and adjust therapy as needed. The patient should be closely monitored for signs of clinical worsening, and CBC and differential should be checked regularly, along with ESR and CRP if necessary.

Some key points to consider in the management of this patient include:

• The need for a more effective antibiotic regimen, taking into account the patient's history of leukopenia and the susceptibility pattern of the infecting organism
• The potential need for surgical intervention, such as debridement and implant retention or prosthesis exchange
• The importance of close monitoring of the patient's white blood cell count and other laboratory parameters
• The need for regular follow-up with both infectious disease and orthopedic specialists to adjust therapy as needed.

It is also important to consider the patient's overall health status, including any comorbidities, and to involve them in the decision-making process regarding their treatment plan. By taking a comprehensive and multidisciplinary approach to the patient's care, it is possible to optimize their treatment outcomes and improve their quality of life. The patient's treatment plan should be individualized based on their specific needs and circumstances, and should take into account the latest evidence-based guidelines and recommendations for the management of prosthetic joint infections. In particular, the guidelines from the Infectious Diseases Society of America 1 provide a useful framework for the diagnosis and management of prosthetic joint infections, and should be consulted in conjunction with other relevant resources and expert opinion.

Overall, the management of this patient requires a careful and nuanced approach, taking into account their complex medical history and the specific challenges of treating prosthetic joint infections. By working closely with the patient and their healthcare team, it is possible to develop an effective treatment plan that addresses their unique needs and optimizes their outcomes. The use of antimicrobial therapy, surgical intervention, and close monitoring and follow-up are all critical components of the patient's treatment plan, and should be carefully coordinated to ensure the best possible results. In addition, the patient's quality of life and overall well-being should be prioritized throughout the treatment process, and their concerns and preferences should be taken into account whenever possible. By adopting a patient-centered and evidence-based approach to the patient's care, it is possible to achieve optimal outcomes and improve their overall health and well-being.

From the FDA Drug Label

PRECAUTIONS General Prescribing cephalexin capsules, cephalexin for oral suspension, or cephalexin tablets in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria Patients should be followed carefully so that any side effects or unusual manifestations of drug idiosyncrasy may be detected. Prolonged use of cephalexin may result in the overgrowth of nonsusceptible organisms. Careful observation of the patient is essential. If superinfection occurs during therapy, appropriate measures should be taken.

The appropriate management plan for a patient with a history of leukopenia and a prosthetic joint infection caused by GBS, currently being treated with cephalexin, includes:

• Continuing suppressive oral antibiotic with cephalexin 500mg po bid for a minimum of one year
• Monitoring the patient's CBCP and diff weekly for 2 weeks, then every 2 weeks for 4 weeks, and monthly thereafter if stable
• Checking ESR and CRP if the patient experiences clinical worsening
• Continuing to work with PT as directed
• Considering aspiration of the R TKA if decreased ROM and medial knee discomfort persist for 1-2 more weeks to evaluate for recurrent PJI 2

From the Research

Management Plan for Patient with History of Leukopenia and Prosthetic Joint Infection

• The patient is currently being treated with cephalexin 500mg po bid for a minimum of one year due to a prosthetic joint infection caused by Group B Streptococcus (GBS) that is resistant to erythromycin, clindamycin, and tetracycline 3.
• Given the patient's history of leukopenia with penicillin (IV PCN G), it is recommended to monitor their complete blood count with platelets (CBCP) and differential count every week for 2 weeks, and if stable, every 2 weeks for 4 weeks, and then monthly thereafter 4, 5.
• If the patient experiences clinical worsening, their CBCP and differential count should be checked along with erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) 4.
• The patient should continue to work with physical therapy (PT) as directed, and if they experience decreased range of motion (ROM) and medial knee discomfort that persists for 1-2 more weeks, they may need aspiration of the right total knee arthroplasty (TKA) to evaluate for recurrent prosthetic joint infection (PJI) 3.
• First-generation cephalosporins, such as cephalexin, are effective for the treatment of acute hematogenous osteomyelitis in children, but may cause adverse effects such as leukopenia and gastrointestinal symptoms 5, 6.
• Patients with a history of penicillin allergy are at increased risk of adverse drug reactions when administered cephalosporins, especially first-generation cephalosporins, and penicillin skin testing is recommended before administering cephalosporins to these patients 7.