From the Guidelines
For patients allergic to augmentin, Bactrim, and Keflex, azithromycin (Zithromax) is a good broad-spectrum antibiotic alternative, with a recommended dose of 12 mg per kg once daily (maximum = 500 mg) for 5 days 1. When considering alternatives for patients with such allergies, it's crucial to select an antibiotic that is effective against a broad range of pathogens and has a favorable safety profile. Azithromycin stands out due to its efficacy against many respiratory, skin, and soft tissue infections, and its mechanism of action, which involves inhibiting bacterial protein synthesis, differs from that of penicillins and cephalosporins, reducing the risk of cross-reactivity in patients with allergies to these classes. Some key points to consider when prescribing azithromycin include:
- Its broad-spectrum activity, which makes it suitable for a variety of infections
- The lack of cross-reactivity with beta-lactam allergies, which is particularly beneficial for patients allergic to augmentin and Keflex
- The convenience of its dosing regimen, which can improve patient compliance
- The importance of considering local resistance patterns and the patient's complete medical history when selecting an antibiotic Other options, such as doxycycline or fluoroquinolones like levofloxacin, may also be considered based on the specific type of infection, local resistance patterns, and the patient's medical history, but azithromycin is a preferred choice due to its safety profile and efficacy 1.
From the Research
Alternatives to Augmentin, Bactrim, and Keflex
If a patient is allergic to Augmentin, Bactrim, and Keflex, there are other broad-spectrum antibiotic options available.
- Linezolid is a synthetic oxazolidinone antibiotic with a unique mechanism of action, effective against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE) 2.
- Combination therapy with linezolid and other antibiotics, such as doxycycline, fosfomycin, levofloxacin, rifampicin, and vancomycin, may be effective against certain infections 3.
- Other antibiotics, such as amoxicillin, piperacillin/tazobactam, cloxacillin, cephalosporins, carbapenems, aztreonam, aminoglycosides, fluoroquinolones, doxycycline, vancomycin, daptomycin, clindamycin, trimethoprim/sulfamethoxazole, fosfomycin, rifampin, dalbavancin, and oritavancin, have shown good penetration into bone and joint tissues, making them potential options for treating bone and joint infections 4.
Considerations for Penicillin Allergy
For patients with a reported penicillin allergy, it is essential to evaluate the allergy history to determine the risk of a clinically significant reaction 5.
- Patients with a low-risk allergy history may be suitable for a direct amoxicillin challenge.
- Moderate-risk patients can be evaluated with penicillin skin testing, which has a high negative predictive value.
- Clinicians should consider the available resources and methods supported by their institution when evaluating penicillin allergy.
Antibiotic Spectrum and Potency
Orally administered cephalosporins and amoxicillin/clavulanate have different antimicrobial spectrums and potencies 6.
- Cefdinir, cefpodoxime, cefprozil, and cefuroxime are highly active against penicillin-susceptible Streptococcus pneumoniae.
- Amoxicillin/clavulanate is the most active against S. pneumoniae, including most penicillin-nonsusceptible strains.
- Amoxicillin/clavulanate, cefdinir, and cefpodoxime are active against Moraxella catarrhalis, including beta-lactamase-producing strains.