What is the treatment for community-acquired pneumonia (CAP) in a patient with a penicillin (pcn) allergy?

From the Guidelines

For patients with a penicillin allergy who have community-acquired pneumonia (CAP), the recommended treatment is a respiratory fluoroquinolone such as levofloxacin (750 mg orally or IV once daily for 5-7 days) or moxifloxacin (400 mg orally or IV once daily for 5-7 days), as stated in the guidelines by the Infectious Diseases Society of America/American Thoracic Society 1. This recommendation is based on the strongest and most recent evidence available, which prioritizes morbidity, mortality, and quality of life as the primary outcomes. Some key points to consider when treating CAP in patients with a penicillin allergy include:

• The use of a respiratory fluoroquinolone, such as levofloxacin or moxifloxacin, is recommended as an alternative agent for empiric antimicrobial therapy 1.
• Macrolides, such as azithromycin or clarithromycin, can be used for non-severe cases, but their effectiveness may be limited by high rates of resistance among certain pathogens 1.
• Doxycycline is another alternative for patients with mild to moderate CAP, and can be used in combination with other agents for more severe cases 1.
• The choice of antibiotic should be guided by local resistance patterns, severity of illness, patient comorbidities, and risk factors for specific pathogens 1.
• Treatment duration typically ranges from 5-7 days for uncomplicated cases to 10-14 days for more severe infections 1. It's also important to note that many patients with reported penicillin allergies can actually tolerate cephalosporins, so allergy clarification is valuable when possible 1.

From the FDA Drug Label

1.2 Community-Acquired Pneumonia: 7 to 14 Day Treatment Regimen Levofloxacin tablets are indicated for the treatment of community-acquired pneumonia due to methicillin-susceptible Staphylococcus aureus, Streptococcus pneumoniae (including multi-drug-resistant Streptococcus pneumoniae [MDRSP]), Haemophilus influenzae, Haemophilus parainfluenzae, Klebsiella pneumoniae, Moraxella catarrhalis, Chlamydophila pneumoniae, Legionella pneumophila, or Mycoplasma pneumoniae MDRSP isolates are isolates resistant to two or more of the following antibacterials: penicillin (MIC ≥ 2 mcg/mL), 2nd generation cephalosporins, e.g., cefuroxime, macrolides, tetracyclines and trimethoprim/sulfamethoxazole.

Treatment for community-acquired pneumonia (CAP) in a patient with a penicillin allergy is levofloxacin, as it is effective against a wide range of bacteria that cause CAP, including those resistant to penicillin 2.

• Key points:
  • Levofloxacin is indicated for the treatment of CAP due to various bacteria, including MDRSP.
  • MDRSP isolates are resistant to two or more antibacterials, including penicillin.
  • Levofloxacin has been shown to be effective in treating CAP in patients with penicillin allergy.

From the Research

Treatment Options for Community-Acquired Pneumonia with Penicillin Allergy

• For patients with a penicillin allergy, alternative antibiotics are necessary to treat community-acquired pneumonia (CAP) effectively.
• Levofloxacin, a fluoroquinolone, has been shown to be effective in treating CAP, including cases caused by atypical pathogens 3, 4.
• The efficacy and tolerability of levofloxacin 500 mg once daily for 10 days in patients with CAP are well established 3.
• A high-dose (750 mg), short-course (5 days) of once-daily levofloxacin has been approved for use in the USA in the treatment of CAP, and has been shown to be at least as effective as a 500-mg, 10-day regimen for atypical CAP 4.
• Levofloxacin can be used as a monotherapy in patients with CAP, but combination therapy with an anti-pseudomonal beta-lactam (or aminoglycoside) should be considered if Pseudomonas aeruginosa is the causative pathogen of the respiratory infection 3.
• Single-agent, high-dose levofloxacin treatment has been shown to exhibit excellent clinical and microbiological efficacy with a safety profile comparable to that of ceftriaxone plus azithromycin therapy 5.

Considerations and Precautions

• Resistance to fluoroquinolones, including levofloxacin, is a concern, and treatment failure has been reported in cases of CAP caused by fluoroquinolone-resistant S. pneumoniae strains 6.
• The choice of antibiotic should be guided by local resistance patterns and patient-specific factors, such as recent antibiotic use and comorbidities 7.
• Levofloxacin is generally well tolerated, but adverse events can occur, and patients should be monitored closely during treatment 3, 5.

Alternative Treatment Options

• Other antibiotics, such as macrolides or doxycycline, may be considered as alternative treatments for CAP in patients with a penicillin allergy, depending on the suspected causative pathogen and local resistance patterns 7.
• Combination therapy with multiple antibiotics may be necessary in severe cases of CAP or in patients with underlying comorbidities 5.