From the Guidelines
For patients allergic to penicillin, the most appropriate alternative antibiotics are macrolides, tetracyclines, fluoroquinolones, and sulfonamides, with the specific choice depending on the infection type, severity, and patient factors, as recommended by the Infectious Diseases Society of America 1. When considering alternative antibiotics for patients allergic to penicillin, it is essential to evaluate the severity of the allergy and the specific 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 for respiratory and skin infections.
- Tetracyclines such as doxycycline (100mg twice daily for 7-14 days) are effective for respiratory and skin infections, as noted in the practice guidelines for skin and soft-tissue infections 1.
- Fluoroquinolones including ciprofloxacin (500mg twice daily) and levofloxacin (500-750mg once daily) are effective for urinary tract and respiratory infections.
- Sulfonamides such as trimethoprim-sulfamethoxazole (one double-strength tablet twice daily) work well for urinary tract infections. It is crucial to note that cephalosporins like cefuroxime (250-500mg twice daily) may be used cautiously, as about 10% of penicillin-allergic patients may cross-react, as highlighted in the clinical practice guideline for the use of antimicrobial agents in neutropenic patients with cancer 1. The choice of alternative antibiotic should be guided by the specific infection, severity, patient factors, and the nature of the penicillin allergy, with consideration of the potential for cross-reactivity and the need for allergy testing, as many patients labeled as penicillin-allergic can actually tolerate these medications 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.