From the Guidelines
For patients with a penicillin allergy who have strep throat, azithromycin is typically recommended as the first-line alternative, with a dosage of 12 mg/kg once daily (maximum 500 mg) for 5 days, as supported by the Infectious Diseases Society of America guidelines 1. The standard adult dosage is 500 mg on the first day, followed by 250 mg daily for the next four days, completing a 5-day course. Other options include:
- Clarithromycin (250-500 mg twice daily for 10 days)
- Clindamycin (300 mg three times daily for 10 days)
- Cephalexin (20 mg per kg per dose twice daily, maximum 500 mg per dose) for 10 days
- Cefadroxil (30 mg per kg once daily, maximum 1 g) for 10 days. It's essential to complete the full course of antibiotics even if symptoms improve before finishing the medication, as emphasized in the guidelines 1. These antibiotics work by inhibiting bacterial protein synthesis, effectively treating the Group A Streptococcus bacteria that causes strep throat. However, in some regions with high macrolide resistance, clindamycin may be preferred, as noted in the guidelines 1. If the penicillin allergy is non-severe or questionable, cephalosporins like cefdinir or cefuroxime might be considered after appropriate risk assessment. The choice of antibiotic should be based on the severity of the allergy, the presence of resistance patterns in the region, and the patient's overall health status, as recommended by the guidelines 1.
From the FDA Drug Label
Clindamycin is also indicated in the treatment of serious infections due to susceptible strains of streptococci, pneumococci, and staphylocci Its use should be reserved for penicillin-allergic patients or other patients for whom, in the judgment of the physician, a penicillin is inappropriate.
For a patient with a penicillin allergy, clindamycin is recommended for the treatment of strep throat, as it is indicated for the treatment of serious infections due to susceptible strains of streptococci 2.
- The physician should consider the nature of the infection and the suitability of less toxic alternatives, such as erythromycin.
- Bacteriologic studies should be performed to determine the causative organisms and their susceptibility to clindamycin.
From the Research
Antibiotic Options for Strep Throat in Patients with Penicillin Allergy
- For patients with a penicillin allergy, alternative antibiotics are necessary to treat strep throat, as penicillin is the typical first-line treatment 3, 4.
- Macrolides, such as erythromycin, clarithromycin, and azithromycin, are commonly used alternatives for patients with penicillin allergies 3, 5.
- Clarithromycin and azithromycin are preferred over erythromycin due to their lower rates of gastrointestinal side effects and more convenient dosing regimens 3, 5.
- Azithromycin is typically administered once daily for 5 days, while clarithromycin is administered twice daily for 10 days 3, 5.
- However, it's essential to note that there is significant resistance to azithromycin and clarithromycin in some parts of the United States, which may impact their effectiveness 4.
- First-generation cephalosporins may also be considered for patients with non-anaphylactic penicillin allergies 4.
Considerations for Antibiotic Selection
- The choice of antibiotic should be based on the patient's specific allergy profile and the severity of their reaction to penicillin 6.
- Clinicians should consider antimicrobial therapy with an antibiotic that does not cross-react with penicillins or beta-lactams 6.
- It's crucial to follow clinical guidelines and consider the patient's medical history, symptoms, and test results when selecting an antibiotic for strep throat treatment 4, 7.