From the Guidelines
For patients allergic to amoxicillin, the most suitable alternative antibiotic for treating streptococcal infections is azithromycin, given its strong, moderate recommendation and effectiveness in treating group A streptococcal pharyngitis 1. When considering alternatives to amoxicillin for streptococcal infections in patients with allergies, several options are available, each with its own set of guidelines and recommendations.
- Azithromycin is prescribed at 12 mg/kg once daily (max = 500 mg) for 5 days, as indicated in the guidelines for individuals with penicillin allergy 1.
- Another option is clarithromycin, typically prescribed at 7.5 mg/kg/dose twice daily (max = 250 mg/dose) for 10 days, also for those allergic to penicillin 1.
- Cephalexin and cefadroxil are alternatives for patients without immediate-type hypersensitivity to penicillin, but they are not recommended for those with severe penicillin allergies due to the risk of cross-reactivity 1.
- Clindamycin is an effective option for more severe cases or when other alternatives are not suitable, prescribed at 7 mg/kg/dose 3 times daily (max = 300 mg/dose) for 10 days 1. It's crucial to note that the choice of antibiotic should be based on the severity of the allergy, the specific patient population (adults or children), and local resistance patterns.
- The mechanism of action of these alternative antibiotics, such as macrolides (azithromycin, clarithromycin) inhibiting bacterial protein synthesis and clindamycin blocking the bacterial ribosome, differs from that of penicillins, making them viable options for patients with amoxicillin allergies.
- Completing the full course of antibiotics is essential, even if symptoms improve quickly, to ensure the complete eradication of the bacteria and prevent potential complications like rheumatic fever or kidney inflammation.
From the FDA Drug Label
Clindamycin is also indicated in the treatment of serious infections due to susceptible strains of streptococci, pneumococci, and staphylococci Its use should be reserved for penicillin-allergic patients or other patients for whom, in the judgment of the physician, a penicillin is inappropriate. Streptococci: Serious respiratory tract infections; serious skin and soft tissue infections.
Alternative antibiotics for treating streptococcal infections in patients allergic to amoxicillin include:
- Clindamycin 2, which can be used to treat serious infections due to susceptible strains of streptococci.
- Azithromycin 3, which can be used as an alternative to first-line therapy in individuals who cannot use first-line therapy for pharyngitis/tonsillitis caused by Streptococcus pyogenes.
From the Research
Alternative Antibiotics for Strep Infections
In patients allergic to amoxicillin, several alternative antibiotics can be considered for treating streptococcal (strep) infections.
- Cephalexin is an effective option, as it has been shown to be comparable to erythromycin, clindamycin, and other cephalosporins in treating streptococcal infections 4.
- Clindamycin may be a better alternative than erythromycin for patients allergic to beta-lactam agents, due to its lower resistance rate (4% vs 21%) 5.
- Cefdinir is another option, with studies demonstrating its superiority to penicillin in eradicating GABHS from the pharynx and achieving clinical cure 6.
- Other alternatives include cefuroxime, cefpodoxime, or cefdinir, which can be used in penicillin-allergic patients or those unresponsive to amoxicillin 7.
- In cases of serious drug allergy, clarithromycin or azithromycin may be prescribed 7.
Considerations for Choosing an Alternative Antibiotic
When selecting an alternative antibiotic, factors such as cost, palatability, and adverse reaction profiles should be considered 4. Additionally, the specific type of streptococcal infection and the patient's medical history should be taken into account.
- The efficacy of cephalexin in treating streptococcal skin infections has been demonstrated, with cure rates of 90% or higher 4.
- Cefdinir has been shown to be effective in treating pharyngitis due to GABHS, with eradication rates of 91.4% and 91.7% for once-daily and twice-daily dosing regimens, respectively 6.
- Clindamycin and erythromycin have been compared in terms of their resistance profiles, with clindamycin exhibiting a lower resistance rate 5.