From the Guidelines
For patients allergic to penicillin, the most suitable alternative antibiotics are macrolides, fluoroquinolones, and tetracyclines, with the specific choice depending on the type and severity of the infection, as well as local resistance patterns, as recommended by the Infectious Diseases Society of America 1. When considering alternative antibiotics for patients with a penicillin allergy, it's essential to evaluate the severity of the allergy and the type of infection being treated.
- Macrolides like azithromycin (500mg once daily for 3-5 days) and clarithromycin (500mg twice daily for 7-14 days) are commonly used alternatives.
- Fluoroquinolones, including ciprofloxacin (500mg twice daily) and levofloxacin (500mg once daily), offer broad-spectrum coverage but should be used judiciously due to resistance concerns and side effects.
- Tetracyclines like doxycycline (100mg twice daily) work well for respiratory and skin infections.
- For serious infections, vancomycin (15-20mg/kg IV every 8-12 hours) or linezolid (600mg twice daily) may be necessary, as suggested by the clinical practice guideline for the use of antimicrobial agents in neutropenic patients with cancer 1. It's crucial to note that most penicillin-allergic patients tolerate cephalosporins, but those with a history of an immediate-type hypersensitivity reaction should be treated with a combination that avoids b-lactams and carbapenems, such as ciprofloxacin plus clindamycin or aztreonam plus vancomycin 1. Patients should inform all healthcare providers about their penicillin allergy and wear a medical alert bracelet. Before starting any antibiotic, allergy testing may be beneficial to confirm the penicillin allergy, as many patients who report such allergies can actually tolerate penicillins safely. The choice of antibiotic should be guided by the most recent and highest-quality evidence, prioritizing morbidity, mortality, and quality of life as outcomes, as seen in the practice guidelines for the diagnosis and management of skin and soft-tissue infections 1.
From the FDA Drug Label
Patients should be directed to discontinue azithromycin immediately and contact a physician if any signs of an allergic reaction occur
Alternative antibiotics for patients allergic to penicillin may include azithromycin. However, it is crucial to monitor for signs of an allergic reaction. If a patient experiences any allergic reaction symptoms, they should discontinue azithromycin and contact their physician immediately 2.
From the Research
Alternative Antibiotics for Bacterial Infections
In patients allergic to penicillin, several alternative antibiotics can be used to treat bacterial infections.
- Macrolides, such as clarithromycin and azithromycin, are effective against a range of bacterial infections, including community-acquired pneumonia (CAP) 3.
- Fluoroquinolones, such as levofloxacin, are also effective against CAP and can be used as an alternative to penicillin 3, 4.
- Cephalosporins, such as cethromycin, can be used in some cases, but cross-reactivity with penicillin can occur in about 2% of cases 5, 6.
Evaluation of Penicillin Allergy
Before using alternative antibiotics, it is essential to evaluate the patient's penicillin allergy history.
- Patients with a low-risk allergy history can undergo direct amoxicillin challenge 5.
- Patients with a moderate-risk history can be evaluated with penicillin skin testing, which has a negative predictive value of over 95% 5.
- Patients with a high-risk history, such as anaphylaxis or positive penicillin skin testing, should avoid penicillin and use alternative antibiotics 5, 6.
Management of Penicillin Allergy
In some cases, desensitization may be used to allow treatment with penicillins 6.