Moraxella catarrhalis Infection Treatment & Management

Updated: Mar 22, 2021
  • Author: Michael Constantinescu, MD; Chief Editor: Michael Stuart Bronze, MD  more...
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Approach Considerations

Medical management of M catarrhalis infection depends on the infection site, age of the patient, underlying condition(s), and severity of the disease.

Consultation with an ear, nose, and throat specialist may be indicated in recurrent cases of otitis or sinusitis. Consultation with an infectious disease specialist is recommended for infections that do not respond to antibiotic treatment, infections in patients with underlying debilitating conditions, systemic infections with M catarrhalis, or infections in unusual locations.

Follow-up care with the patient’s primary care physician is highly recommended. Worsening symptoms warrant a return visit to the primary care physician.


Pharmacologic Therapy

Any of a number of antimicrobial drugs may be used to treat M catarrhalis infection, depending on the need for use of oral or parenteral medication, the age of the patient, any underlying conditions present, the sensitivity of the organism, and the desired spectrum of coverage.

Approximately 95% of M catarrhalis strains isolated in the United States produce beta-lactamase. Antibiotics such as penicillin, amoxicillin, and ampicillin are only effective against strains that do not produce beta-lactamase.

Amoxicillin-clavulanate, second- and third-generation oral cephalosporins, and trimethoprim-sulfamethoxazole (TMP-SMZ) are the most recommended agents. Alternatively, azithromycin or clarithromycin can be used. More than 90% of M catarrhalis strains have been shown to resist amoxicillin, and these rates vary by region. [20]

In one study, topical use of ciprofloxacin/dexamethasone for treatment of acute otitis media with otorrhea via tympanostomy tubes was found to have similar efficacy to that of topical use of ofloxacin in M catarrhalis infections. [21]

In another study, treatment with oral azithromycin 500 mg once daily for 3 days was found to be comparable with a 10-day regimen of oral clarithromycin 500 mg twice daily for the treatment of acute exacerbation of chronic bronchitis. [22]

Telithromycin, a ketolide derivative of erythromycin A, demonstrated good in vitro activity against M catarrhalis in a study of patients with acute exacerbations of chronic bronchitis. [23] However, severe liver disease associated with telithromycin use has been reported. [24] Note that telithromycin is not indicated for use in patients with myasthenia gravis.

Moxifloxacin, a quinolone, was found to be an effective treatment of M catarrhalis– associated community-acquired pneumonia in a dosage of 400 mg/day. [25]



Universal precautions, good hand-washing technique, and sterilization of instruments and tubes used in intubations, aspiration, or invasive procedures may reduce or prevent the nosocomial infections caused by M catarrhalis. Cessation of smoking and prevention of passive smoking may reduce M catarrhalis infections. Good general health habits (eg, proper rest, exercise, and diet) are helpful as well.

Research is under way to create a vaccine to prevent M catarrhalis infections. [26, 27] It is projected that 4.2 million episodes of otitis media would be prevented by a combined pneumococcal-nontypeable H influenzaeMoraxella vaccine. [28]