Should I change to oral antibiotics for an intranasal furuncle with heavy growth of Pseudomonas aeruginosa and Acinetobacter calcoaceticus while on topical Bactroban (mupirocin)?

From the Guidelines

You should consider changing to oral antibiotics for an intranasal furuncle with heavy growth of Pseudomonas aeruginosa and Acinetobacter calcoaceticus while on topical mupirocin. Mupirocin (Bactroban) is not typically effective against these gram-negative bacteria, which explains why the infection persists. For Pseudomonas and Acinetobacter, consider oral ciprofloxacin 500-750 mg twice daily for 7-10 days, or levofloxacin 750 mg once daily for 7-10 days, as suggested by 1. These fluoroquinolones provide good coverage against both organisms. Alternatively, if susceptibility testing allows, trimethoprim-sulfamethoxazole (Bactrim DS) one tablet twice daily for 7-10 days might be effective. While taking oral antibiotics, continue warm compresses to the area 3-4 times daily to help with drainage. Seek immediate medical attention if you develop fever, increasing pain, spreading redness, or swelling extending to the surrounding facial areas, as these may indicate a worsening infection requiring more aggressive treatment. The reason for changing to systemic antibiotics is that these gram-negative bacteria can cause persistent infections that topical treatments alone cannot adequately address, especially in the nasal vestibule where absorption of topical agents may be limited, and the choice of antibiotic should be based on antimicrobial susceptibility testing as recommended by 1. Key considerations include:

• The potential for antibiotic resistance
• The need for susceptibility testing to guide antibiotic choice
• The importance of monitoring for signs of worsening infection
• The role of warm compresses in promoting drainage and healing.

From the FDA Drug Label

Skin and Skin Structure Infections caused by Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Proteus mirabilis, Proteus vulgaris, Providencia stuartii, Morganella morganii, Citrobacter freundii, Pseudomonas aeruginosa, methicillin-susceptible Staphylococcus aureus, methicillin-susceptible Staphylococcus epidermidis, or Streptococcus pyogenes

• The Pseudomonas aeruginosa is listed as one of the causative organisms for which ciprofloxacin is effective.
• However, Acinetobacter calcoaceticus is not listed as a susceptible organism in the provided drug label.
• The patient is currently on topical Bactroban (mupirocin), but the label for ciprofloxacin does not provide information on switching from topical to oral antibiotics.
• Given the presence of Pseudomonas aeruginosa, which is susceptible to ciprofloxacin, and considering the lack of information on Acinetobacter calcoaceticus, it would be reasonable to consider changing to oral antibiotics, such as ciprofloxacin, but only if the infection is severe or not responding to topical treatment 2.
• It is essential to note that culture and susceptibility testing should be performed before initiating treatment to ensure the chosen antibiotic is effective against the causative organisms.

From the Research

Intranasal Furuncle Treatment

• The presence of heavy growth of Pseudomonas aeruginosa and Acinetobacter calcoaceticus in an intranasal furuncle swab result indicates a complex infection requiring effective antibiotic treatment.
• Topical Bactroban (mupirocin) is currently being used, but the question arises whether oral antibiotics should be considered.

Oral Antibiotic Considerations

• Studies have shown that combination therapy with certain antibiotics can be effective against Pseudomonas aeruginosa, such as ceftazidime, ciprofloxacin, and piperacillin-tazobactam 3, 4, 5.
• Ceftazidime has been found to be a potent antipseudomonal agent, with a long duration of activity 6.
• Combination therapy with levofloxacin or ciprofloxacin and ceftazidime, cefepime, imipenem, piperacillin-tazobactam, or amikacin has shown synergy and additivity against Pseudomonas aeruginosa and Acinetobacter spp. 7.

Decision to Change to Oral Antibiotics

• Based on the evidence, oral antibiotics such as ceftazidime, ciprofloxacin, or piperacillin-tazobactam could be considered as an alternative or addition to topical Bactroban, especially if the infection is severe or not responding to topical treatment 3, 4, 5.
• However, the decision to change to oral antibiotics should be made on a case-by-case basis, taking into account the severity of the infection, patient's overall health, and potential side effects of oral antibiotics.
• It is essential to consult with a healthcare professional to determine the best course of treatment for the specific case, considering the latest clinical guidelines and evidence-based practices 3, 4, 6, 5, 7.