What is the next appropriate step in management and IV antibiotic for a patient with worsening symptoms from a cat bite despite being on Augmentin (amoxicillin-clavulanate)?

From the Guidelines

For a patient with worsening symptoms from a cat bite despite Augmentin therapy, hospitalization for IV antibiotics is the next appropriate step. The recommended IV antibiotic regimen would be ampicillin-sulbactam (Unasyn) 1.5–3.0 g every 6–8 hours or piperacillin-tazobactam (Zosyn) 3.37 g every 6–8 hours, as these regimens are recommended for animal bites, including cat bites, according to the guidelines from the Infectious Diseases Society of America 1. If the patient has a penicillin allergy, alternatives include a carbapenem such as ertapenem or the combination of clindamycin plus a fluoroquinolone like ciprofloxacin, as these options provide broad coverage against the polymicrobial infections commonly associated with cat bites, including Pasteurella multocida, streptococci, staphylococci, and anaerobes 1. Treatment duration typically ranges from 7-14 days depending on clinical response. Cat bites often cause polymicrobial infections which can rapidly progress despite oral antibiotics. Pasteurella is highly sensitive to penicillins but may develop resistance or form abscesses that require drainage. Additionally, deep tissue infections may need surgical debridement alongside antibiotic therapy. Close monitoring of the infection site, inflammatory markers, and clinical symptoms is essential to determine response to the new treatment regimen. It's also important to note that the bacteriology of these wounds can differentiate the number of isolates per wound and whether additional coverage for anaerobes is required, as some gram-negative rods are resistant to certain antibiotics and MRSA is not covered by some of the recommended regimens 1.

Some key points to consider in the management of cat bites include:

• The high risk of polymicrobial infections, including Pasteurella multocida, which is highly sensitive to penicillins but may develop resistance or form abscesses that require drainage.
• The potential for deep tissue infections that may need surgical debridement alongside antibiotic therapy.
• The importance of close monitoring of the infection site, inflammatory markers, and clinical symptoms to determine response to the new treatment regimen.
• The need to consider the bacteriology of the wound and whether additional coverage for anaerobes is required.
• The potential for resistance to certain antibiotics, including some gram-negative rods and MRSA, which may not be covered by some of the recommended regimens.

Overall, the management of cat bites requires careful consideration of the potential for polymicrobial infections, the need for broad-spectrum antibiotic coverage, and the importance of close monitoring and potential surgical intervention.

From the Research

Next Appropriate Step in Management

• The patient's worsening symptoms despite being on Augmentin (amoxicillin-clavulanate) suggest that the current antibiotic treatment may not be effective against the causative pathogen of the cat bite infection.
• Considering the potential for antibiotic resistance, it is essential to reassess the patient's condition and consider alternative antibiotic treatments 2.
• The patient should be evaluated for signs of infection severity, such as increased redness, swelling, or purulent discharge, and laboratory tests (e.g., complete blood count, blood cultures) may be ordered to guide further management.

Most Appropriate Next Antibiotic IV

• Given the potential for methicillin-resistant Staphylococcus aureus (MRSA) or other resistant organisms in cat bite infections, broad-spectrum antibiotic coverage may be necessary.
• Piperacillin/tazobactam has been shown to be effective against a variety of bacterial pathogens, including MRSA, and may be a suitable alternative to Augmentin 3, 4, 5.
• However, it is crucial to note that the choice of antibiotic should be guided by the patient's clinical presentation, laboratory results, and local antimicrobial resistance patterns.
• Meropenem/piperacillin/tazobactam combination therapy has also demonstrated efficacy against MRSA and other resistant organisms, but its use should be reserved for severe or complicated infections 4.