Should a patient with longstanding leg wounds and a recent course of cefazolin (Ancef) be commenced on flucloxacillin (Fluclox) immediately for a Staphylococcus infection sensitive to flucloxacillin, or can treatment be delayed until morning?

From the Guidelines

The patient should be commenced on flucloxacillin overnight rather than waiting until morning for review. Since the patient has a positive culture for Staphylococcus that is sensitive to flucloxacillin, and they've recently completed a course of cefazolin without complete resolution, prompt initiation of appropriate antibiotic therapy is warranted 1. For adults, the typical flucloxacillin dosing would be 500mg orally four times daily (or 1-2g IV every 6 hours if severe infection). The duration would typically be 1-2 weeks depending on clinical response, with reassessment after starting therapy. Although the patient is currently afebrile and stable, delaying appropriate antibiotic therapy for wound infections can lead to worsening infection, potential spread, and increased difficulty in eradication. Flucloxacillin is a narrow-spectrum penicillinase-resistant penicillin that specifically targets the identified pathogen, making it a more targeted choice than cefazolin. The previous treatment failure with cefazolin despite in vitro sensitivity suggests the need for this change in antibiotic strategy without delay. According to the WHO's essential medicines and aware recommendations, flucloxacillin is a preferred option for skin and soft tissue infections caused by Staphylococcus aureus 1.

Some key points to consider in this decision include:

• The patient's recent completion of a course of cefazolin without complete resolution, indicating the need for a change in antibiotic strategy
• The positive culture for Staphylococcus that is sensitive to flucloxacillin, making it a targeted choice for treatment
• The potential risks of delaying appropriate antibiotic therapy, including worsening infection and increased difficulty in eradication
• The WHO's recommendations for the use of flucloxacillin in skin and soft tissue infections caused by Staphylococcus aureus 1.

It's also important to note that the Infectious Diseases Society of America guidelines recommend the use of antibiotics such as flucloxacillin for the treatment of skin and soft tissue infections caused by Staphylococcus aureus 1. However, the most recent and highest quality study, which is the 2024 study from the Clinical Microbiology and Infection journal, supports the use of flucloxacillin as a first-line treatment option for skin and soft tissue infections caused by Staphylococcus aureus 1.

From the FDA Drug Label

The oral route of administration should not be relied upon in patients with severe illness, or with nausea, vomiting, gastric dilation, cardiospasm, or intestinal hypermotility. Patients should be told to take the entire course of therapy prescribed, even if fever and other symptoms have stopped

The patient seems to be afebrile and stable, and has recently completed a course of cefazolin. There is no information in the drug label that suggests a specific timing for initiating flucloxacillin treatment.

• The decision to start flucloxacillin overnight or wait until morning for review should be based on clinical judgment, considering the patient's condition and the potential risks and benefits of delaying treatment.
• Given the patient's stable condition, it is likely safe to wait until morning for review before initiating flucloxacillin treatment 2.

From the Research

Patient Assessment

• The patient has longstanding leg wounds and has grown positive for staph sensitive to fluclox.
• The patient seems to be afebrile and stable.
• The patient recently completed a course of cefazolin.

Treatment Considerations

• According to 3, penicillinase-resistant penicillins (e.g. flucloxacillin) are the preferred drugs for all methicillin-susceptible staphylococcal infections.
• The study 4 suggests that an oral absorption test can be used to determine if a patient can be switched to oral flucloxacillin, but it does not provide guidance on the timing of initiation.
• There is no evidence in the provided studies to suggest that the patient's condition requires immediate initiation of fluclox overnight.
• The patient's stability and recent completion of a course of cefazolin suggest that waiting until morning for review may be a reasonable approach.

Key Factors

• The patient's susceptibility to fluclox and stability are key factors in determining the appropriate course of action.
• The lack of evidence on the optimal timing of fluclox initiation in this scenario means that clinical judgment should be used to determine the best approach.