From the FDA Drug Label
Levofloxacin has in vitro activity against Gram-negative and Gram-positive bacteria fections as described in Indications and Usage (1): Gram-PositiveBacteria Streptococcus pneumoniae (including multi-drug resistant isolates [MDRSP] ) Gram-Negative Bacteria Haemophilus influenzae Moraxella catarrhalis
For a patient with a penicillin allergy, after an initial course of clarithromycin, levofloxacin can be considered as a second course of treatment for sinusitis, as it has in vitro activity against Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, which are common causes of sinusitis 1.
- Key points:
- Levofloxacin is a fluoroquinolone antibiotic
- It has a different mechanism of action compared to penicillins and macrolides, such as clarithromycin
- It can be active against bacteria resistant to other antimicrobials
- Note: The choice of antibiotic should always be guided by susceptibility patterns and clinical judgment.
From the Research
For a second course of antibiotic treatment for sinusitis in a patient with penicillin allergy who has failed clarithromycin therapy, levofloxacin would be an appropriate choice. The recommended dosage is 500 mg orally once daily for 5-7 days for acute sinusitis or 10-14 days for chronic sinusitis. Levofloxacin is a fluoroquinolone antibiotic that works by inhibiting bacterial DNA gyrase and topoisomerase IV, preventing DNA replication and ultimately killing the bacteria. It provides good coverage against common sinusitis pathogens including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, including some strains that may be resistant to macrolides like clarithromycin 2.
Key Points to Consider
- Levofloxacin has been shown to be as effective as clarithromycin in the treatment of acute bacterial sinusitis, with a higher rate of clinical success and fewer adverse events 3.
- Alternative options could include doxycycline (100 mg twice daily for 5-10 days) or trimethoprim-sulfamethoxazole (one double-strength tablet twice daily for 7-10 days).
- Patients should complete the full course of antibiotics even if symptoms improve before completion.
- They should also be advised about potential side effects of levofloxacin, including tendon inflammation or rupture, and to seek medical attention if they experience tendon pain, joint pain, or muscle weakness.
Rationale for Choice
The choice of levofloxacin is based on its efficacy and safety profile, as well as its ability to provide broad coverage against common sinusitis pathogens. The study by the Canadian Sinusitis Study Group 2 demonstrated that levofloxacin was as effective as clarithromycin in the treatment of acute sinusitis, with a higher rate of clinical success and fewer adverse events. Additionally, the study published in Pharmacotherapy 3 showed that levofloxacin had an advantage over clarithromycin based on two quality-of-life parameters.
Important Considerations
- It is essential to note that the patient has a penicillin allergy, and therefore, penicillin-based antibiotics should be avoided.
- The patient has already failed clarithromycin therapy, and therefore, alternative antibiotics should be considered.
- The choice of antibiotic should be based on the patient's medical history, allergy status, and the severity of the infection.