What is the treatment for penicillin (PCN) allergy in a patient with streptococcal infection?

From the Guidelines

For patients with strep throat who are allergic to penicillin, the recommended alternative treatment is macrolide antibiotics such as azithromycin (12 mg/kg once daily, maximum 500 mg, for 5 days) or clarithromycin (7.5 mg/kg/dose twice daily, maximum 250 mg/dose, for 10 days), as stated in the 2012 update by the Infectious Diseases Society of America 1.

Treatment Options

• For those with non-severe penicillin allergies, first-generation cephalosporins like cephalexin (20 mg/kg/dose twice daily, maximum 500 mg/dose, for 10 days) may be used, as cross-reactivity is low 1.
• Clindamycin (7 mg/kg/dose three times daily, maximum 300 mg/dose, for 10 days) is another effective option, particularly for patients with severe penicillin allergies 1.

Importance of Completing Treatment

It's crucial to complete the full course of antibiotics even if symptoms improve quickly to prevent complications like rheumatic fever.

Additional Recommendations

• Patients should also rest, stay hydrated, use throat lozenges or warm salt water gargles for symptom relief, and take acetaminophen or ibuprofen for pain and fever.
• If symptoms worsen or don't improve after 48 hours of antibiotic treatment, patients should follow up with their healthcare provider.

Key Considerations

• The choice of antibiotic should be based on the patient's allergy history, the severity of the infection, and the potential for resistance.
• The American Heart Association recommends that patients with a history of rheumatic fever should receive continuous antimicrobial prophylaxis to prevent recurrences 1.

From the FDA Drug Label

Erythromycin tablets are indicated for the treatment of penicillin-allergic patients. The therapeutic dose should be administered for ten days. Prevention of Initial Attacks of Rheumatic Fever Penicillin is considered by the American Heart Association to be the drug of choice in the prevention of initial attacks of rheumatic fever (treatment of Streptococcus pyogenes infections of the upper respiratory tract e.g., tonsillitis, or pharyngitis). In patients who are allergic to penicillin and sulfonamides, oral erythromycin is recommended by the American Heart Association in the long-term prophylaxis of streptococcal pharyngitis (for the prevention of recurrent attacks of rheumatic fever). Primary syphilis caused by Treponema pallidum. Erythromycin (oral forms only) is an alternative choice of treatment for primary syphilis in patients allergic to the penicillins. Lower respiratory tract infections of mild to moderate severity caused by Streptococcus pyogenes or Streptococcus pneumoniae.

The treatment for penicillin (PCN) allergy in a patient with streptococcal infection is Erythromycin. The therapeutic dose should be administered for ten days. Erythromycin is an alternative choice of treatment for patients allergic to penicillins, as recommended by the American Heart Association for the prevention of initial and recurrent attacks of rheumatic fever 2.

• Key points:
  • Erythromycin is indicated for the treatment of penicillin-allergic patients.
  • The therapeutic dose should be administered for ten days.
  • Erythromycin is recommended by the American Heart Association for the long-term prophylaxis of streptococcal pharyngitis.
• Main idea: Erythromycin is a suitable alternative for patients with penicillin allergy and streptococcal infection.

From the Research

Treatment Options for Penicillin Allergy in Streptococcal Infection

• For patients allergic to penicillin, alternative treatments are required to manage streptococcal pharyngitis/tonsillitis, as penicillin is the primary drug of choice 3.
• Erythromycin is generally effective in treating this infection but has limitations, such as the need for multiple daily doses and a high rate of gastrointestinal side effects 3, 4.
• Newer macrolides like clarithromycin and azithromycin offer lower rates of gastrointestinal complaints and more convenient dosing, making them rational alternatives to erythromycin for penicillin-allergic patients 3.
• First-generation cephalosporins are also recommended as alternatives in patients with penicillin allergy, with some studies suggesting their use in all non-allergic patients due to better GABHS eradication and effectiveness against chronic GABHS carriage 5, 6.
• The treatment duration for azithromycin is typically 5 days, compared to 10 days for penicillin, erythromycin, and clarithromycin 3.
• Erythromycin estolate and ethylsuccinate are effective in treating streptococcal pharyngitis, with appropriate daily dosages and treatment durations of 10 days 4.
• Low-dose oral erythromycin has been shown to be effective in preventing S. pyogenes infection in penicillin-allergic individuals, making it a viable alternative to benzathine penicillin G 7.