What are the alternative antibiotic treatments for a patient with a penicillin allergy?

From the Guidelines

For patients with a penicillin allergy, the most suitable alternative antibiotic treatment is often a cephalosporin, such as cefdinir or cefuroxime, due to their low cross-reactivity with penicillin and effectiveness against a wide range of bacterial infections 1. When considering alternative antibiotic treatments for patients with a penicillin allergy, several factors must be taken into account, including the type and severity of the infection, local resistance patterns, and the nature of the penicillin allergy.

• Cephalosporins, such as cefdinir (14 mg/kg per day in 1 or 2 doses) or cefuroxime (30 mg/kg per day in 2 divided doses), are commonly used alternatives for patients with penicillin allergies, as they have a distinct chemical structure that reduces the risk of cross-reactivity 1.
• Macrolides, such as azithromycin (12 mg/kg once daily, maximum 500 mg) or clarithromycin (7.5 mg/kg per dose twice daily, maximum 250 mg per dose), are also effective for respiratory infections and can be used as alternative treatments for patients with penicillin allergies 1.
• Fluoroquinolones, such as levofloxacin or ciprofloxacin, and tetracyclines, such as doxycycline, may also be considered for certain types of infections, but their use should be guided by local resistance patterns and the severity of the infection. It is essential to note that the risk of cross-reactivity between penicillins and cephalosporins is lower than historically reported, and many patients labeled as allergic to penicillin can actually tolerate cephalosporins safely 1.
• Consultation with an allergist for penicillin allergy testing is recommended to determine the best course of treatment for each individual patient. The choice of alternative antibiotic treatment should be based on the most recent and highest-quality evidence available, taking into account the specific needs and circumstances of each patient 1.

From the FDA Drug Label

Clindamycin is indicated in the treatment of serious infections caused by susceptible anaerobic bacteria. 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. Syphilis–early: Patients who are allergic to penicillin should be treated with doxycycline 100 mg, by mouth, twice a day for 2 weeks Syphilis of more than one year’s duration: Patients who are allergic to penicillin should be treated with doxycycline 100 mg, by mouth, twice a day for 4 weeks.

Alternative antibiotic treatments for a patient with a penicillin allergy include:

• Clindamycin for serious infections caused by susceptible anaerobic bacteria, streptococci, pneumococci, and staphylococci 2
• Doxycycline for syphilis, including early and late stages, in patients allergic to penicillin 3

From the Research

Alternative Antibiotic Treatments

For patients with a penicillin allergy, several alternative antibiotic treatments are available. These include:

• First generation cephalosporins (e.g., cefazolin, cephalothin, and cephalexin) for less serious methicillin-susceptible S. aureus (MSSA) infections, although they are contra-indicated in patients with immediate penicillin hypersensitivity 4
• Clindamycin, lincomycin, and erythromycin for less serious MSSA infections such as skin and soft tissue infections 4
• Vancomycin or teicoplanin for serious MRSA infections 4
• Lincosamides (clindamycin, lincomycin) or cotrimoxazole for less serious non-multiresistant MRSA (nmMRSA) infections such as skin and soft tissue infections 4
• New antibiotics such as linezolid and quinupristin/dalfopristin for patients who fail on or are intolerant of conventional therapy or who have highly resistant strains 4
• Piperacillin/tazobactam with or without vancomycin for nosocomial complicated skin and soft tissue infections 5
• Clindamycin rather than a macrolide for empirical antibacterial therapy of community-acquired skin and soft tissue infections in penicillin-allergic patients 5
• Carbapenems, oxazolidinones, and streptogramins for life-threatening situations and/or when resistant pathogens are suspected 5

Desensitization

For patients with a penicillin allergy who require treatment with beta-lactam antibiotics, desensitization is an option. This involves administering the antibiotic orally, starting with a small dose and gradually increasing it until a full therapeutic dose is reached 6. Desensitization has been shown to be effective and relatively safe, with no deaths, anaphylaxis, or severe acute allergic reactions reported in one study 6.

Evaluation and Management

Evaluation and management of penicillin allergy is important to ensure that patients receive the most effective and safe treatment. This includes assessing the patient's medical history to determine their risk of developing an allergic reaction to penicillin 7. Patients with a low-risk history may undergo direct amoxicillin challenge, while those with a moderate-risk history may require penicillin skin testing 7. Clinicians should identify the methods supported by their available resources to evaluate penicillin allergy and make informed decisions about treatment 7.