What antibiotic can be used to treat a lower respiratory infection in a patient with an allergy to penicillin and erythromycin (Erythromycin)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: May 14, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

For a patient with a lower respiratory infection who has allergies to both penicillin and erythromycin, levofloxacin is a suitable treatment option, as it provides good coverage against common respiratory pathogens, including Streptococcus pneumoniae and Haemophilus influenzae, and is an alternative choice in certain circumstances, such as intolerance to penicillins 1. When considering treatment options, it's essential to note that levofloxacin has enhanced pneumococcal activity and is licensed for severe pneumonia in the UK 1. The recommended dose for levofloxacin is 500 mg once daily, orally or intravenously, depending on the severity of the infection and the patient's ability to take oral medications 1. Some key points to consider when prescribing levofloxacin include:

  • Assessing renal function to ensure appropriate dosing, as fluoroquinolones are excreted primarily by the kidneys 1
  • Advising patients to take the medication with food to minimize gastrointestinal upset
  • Monitoring for potential side effects, such as photosensitivity and tendonitis, although these are rare
  • Considering alternative treatment options, such as doxycycline, in cases where levofloxacin is not suitable or available 1 It's also important to note that most patients with lower respiratory infections can be adequately treated with oral antibiotics, and the preferred choice includes co-amoxiclav or a tetracycline, but in cases of allergy to penicillin and erythromycin, levofloxacin is a viable alternative 1.

From the FDA Drug Label

Clinical success rates in clinically and microbiologically evaluable patients at the posttherapy visit (primary study endpoint assessed on day 3 to 15 after completing therapy) were 58.1% for levofloxacin and 60. 6% for comparator. Clinical success (cure plus improvement) with levofloxacin at 5 to 7 days posttherapy, the primary efficacy variable in this study, was superior (95%) to the control group (83%). For both studies, the clinical success rate in patients with atypical pneumonia due to Chlamydophila pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila were 96%, 96%, and 70%, respectively.

Levofloxacin can be used to treat a lower respiratory infection when the patient has an allergy to penicillin and erythromycin.

  • The drug has shown clinical success rates of 58.1% to 95% in various studies.
  • It is effective against atypical pneumonia caused by Chlamydophila pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila.
  • It is also effective against multi-drug resistant Streptococcus pneumoniae (MDRSP), with a clinical success rate of 95% 2.

From the Research

Anabiotic Options for Lower Respiratory Infections

When a patient has an allergy to penicillin and erythromycin, alternative anabiotic options can be considered for the treatment of lower respiratory infections.

  • Fluoroquinolones, such as levofloxacin, moxifloxacin, gatifloxacin, and gemifloxacin, are effective against a wide range of pathogens, including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis 3, 4.
  • These antibiotics have been shown to achieve high clinical cure rates in patients with community-acquired pneumonia and acute exacerbations of chronic bronchitis 3, 4, 5.
  • Levofloxacin, in particular, is a valuable antimicrobial agent for the treatment of lower respiratory tract infections, including community-acquired pneumonia and hospital-acquired pneumonia 5.
  • When selecting an antibiotic for a patient with a penicillin allergy, it is essential to consider the severity of the allergic reaction and choose an antibiotic that does not cross-react with penicillins or beta-lactams 6.

Considerations for Antibiotic Selection

  • The choice of antibiotic should be based on the suspected or confirmed pathogen, as well as the patient's allergy history and other medical conditions 4, 6.
  • High-dose, short-course therapy regimens may be effective in reducing the development of resistance and improving treatment outcomes 4, 5.
  • It is crucial to limit antibiotic prescriptions to clinical situations where they are necessary and to use non-antibiotic treatments whenever possible 7.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Levofloxacin for the treatment of respiratory tract infections.

Expert opinion on pharmacotherapy, 2012

Research

Antibiotic selection in the penicillin-allergic patient.

The Medical clinics of North America, 2006

Research

Antibiotic treatment of lower respiratory tract infections.

Archives de pediatrie : organe officiel de la Societe francaise de pediatrie, 2017

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.