What are the next best treatment options for a patient with a Penicillin (PCN) allergy and sinusitis who didn't respond to azithromycin?

From the Guidelines

For a patient with penicillin allergy and sinusitis who failed azithromycin therapy, the next best treatment options include doxycycline (100mg twice daily for 5-7 days) or a respiratory fluoroquinolone such as levofloxacin (750mg once daily for 5-7 days) or moxifloxacin (400mg once daily for 5-7 days). Doxycycline is generally preferred as first-line alternative due to its safety profile and lower risk of adverse effects compared to fluoroquinolones, as suggested by the American College of Physicians and the Centers for Disease Control and Prevention 1. For patients with moderate to severe disease or risk factors for resistant organisms, fluoroquinolones may be more appropriate. If the penicillin allergy is non-severe (no anaphylaxis or angioedema), consider cefdinir (300mg twice daily for 5-7 days) or cefuroxime (500mg twice daily for 5-7 days), as cross-reactivity with cephalosporins is low (around 2%) 1. These medications provide coverage against common sinusitis pathogens including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, including beta-lactamase producing strains that may have contributed to the initial treatment failure.

Some key points to consider when choosing an antibiotic include:

• The severity of the patient's symptoms and the risk of resistant organisms
• The patient's allergy history and potential for cross-reactivity with cephalosporins
• The safety profile and potential adverse effects of the chosen antibiotic
• The need for supportive measures like saline irrigation, intranasal corticosteroids, and decongestants to alleviate symptoms. Supportive measures like saline irrigation, intranasal corticosteroids, and decongestants should be continued alongside antibiotic therapy, as recommended by the American Academy of Otolaryngology–Head and Neck Surgery 1.

It's also important to note that acute uncomplicated rhinosinusitis is a self-limited infection that usually resolves without antibiotics, even in patients with a bacterial cause, and most patients diagnosed with acute rhinosinusitis have more adverse effects than benefits from antibiotics 1. However, in this case, the patient has already failed azithromycin therapy, and therefore, further antibiotic treatment is necessary.

In terms of the duration of antibiotic therapy, a 10- to 14-day course of antibiotic might be adequate for most patients with acute disease, but some experts suggest that patients should be treated until they are free of symptoms plus 7 days, as suggested by the Journal of Allergy and Clinical Immunology 1.

From the Research

Treatment Options for Penicillin Allergy and Sinusitis

Given the patient's allergy to Penicillin (PCN) and lack of response to azithromycin, the following treatment options can be considered:

• Amoxicillin-clavulanate: This is a suitable alternative for patients allergic to penicillin or unresponsive to amoxicillin 2.
• Cefuroxime, cefpodoxime, or cefdinir: These are other options for patients with a PCN allergy 2.
• Clarithromycin: This can be prescribed in cases of serious drug allergy 2.
• Erythromycin ethylsuccinate and sulfisoxazole or TMP-SMZ: These can be used in patients who are allergic to penicillin 3.
• High-dose amoxicillin, with or without clavulanate, or clindamycin: These should be considered when penicillin-resistant pneumococcus is suspected 3.

Considerations for Treatment

When selecting a treatment option, it is essential to consider the following:

• The prevalence of beta-lactamase-producing pathogens in the geographic area 4.
• The patient's response to previous treatments, such as amoxicillin 4.
• The potential for adverse events, such as gastrointestinal disturbances 5.

Symptom Resolution

The speed of symptom resolution is an important consideration when evaluating treatment options. A study comparing azithromycin extended release with levofloxacin found that a single 2-g dose of azithromycin extended release was as efficacious as 10 days of levofloxacin in adults with acute bacterial rhinosinusitis 5. However, since the patient did not respond to azithromycin, alternative treatments should be explored.