Acute Rhinosinusitis Organism-Specific Therapy

Acute rhinosinusitis may be defined as inflammation of the nasal cavity and paranasal sinuses lasting for less than 4 weeks. It is a common ailment encountered in the outpatient setting, affecting close to 35 million people annually. ^[1] The estimated prevalence of viral infection during an episode of acute sinusitis is 90-98%; bacterial infection accounts for 2-10% of cases. ^{[2, 3]} In general, sinus aspiration to obtain or quantify bacterial isolates is not indicated to establish the diagnosis of acute bacterial rhinosinusitis, and antibiotics are usually not targeted against a specific organism. ^{[4, 5, 3]} However, if a specific pathogen is isolated and susceptibility testing is performed, organism-specific treatment is suggested as described below. ^{[3, 6, 7]}

Rhinovirus:

See the list below:

• Supportive therapy only

Influenza:

See the list below:

• Oseltamivir 75 mg PO q12h for 5d

Parainfluenza:

See the list below:

• Supportive therapy only

Streptococcal pneumonia (penicillin susceptible):

• Amoxicillin 500 mg PO q8h or

• Amoxicillin-clavulanate (875 mg/125 mg) PO q12h or

• Doxycycline 100 mg PO q12h

S pneumonia (penicillin intermediate or resistant) *:

• Doxycycline 100 mg PO q12h or

• Amoxicillin-clavulanate (2 g PO q12h)* or

• Moxifloxacin 400 mg PO q24h* or

• Levofloxacin 500 mg PO q24h* or

• Ceftriaxone 1-2 g IV q12-24h* or

• Cefotaxime 2 g IV q4-6h

*Recommended regimens for patients in areas of high endemic rates of penicillin-resistant S pneumoniae, with severe infection, who attend daycare, are aged 2 years or older than 65 years, were recently hospitalized, used antibiotics within the past month, and/or are immunocompromised. IV regimens are recommended for patients with severe infection requiring hospitalization. ^[3]

Haemophilus influenzae:

See the list below:

• Amoxicillin-clavulanate (875 mg/125 mg) PO q12h or

• Doxycycline 100 mg PO q12h or

• Moxifloxacin 400 mg PO q24h or

• Levofloxacin 500 mg PO q24h or

• Ceftriaxone 1-2 g IV q12-24h* or

• Cefotaxime 2 g IV q4-6h*

*IV regimens are recommended for patients with severe infection requiring hospitalization. ^[3]

Moraxella catarrhalis:

See the list below:

• Amoxicillin-clavulanate (875 mg/125 mg) PO q12h or

• Trimethoprim-sulfamethoxazole (160 mg/800 mg) 1 DS tablet PO q12h* or

• Clarithromycin 500 mg PO q12h or extended-release 1 g PO q24h or

• Azithromycin 500 mg in a single dose, then 250 mg PO q24h or

• Doxycycline 100 mg PO q12h or

• Moxifloxacin 400 mg PO q24h or

• Levofloxacin 500 mg PO q24h

*Trimethoprim-sulfamethoxazole resistances rates of up to 50% have been reported in M catarrhalis. ^[6]

Staphylococcus aureus (methicillin-resistant, MRSA):

• Trimethoprim-sulfamethoxazole (160 mg/800 mg) 1-2 DS tablet PO q12h or

• Clindamycin 300 mg PO q6h or

• Doxycycline 100 mg PO q12h

Staphylococcus aureus (methicillin-susceptible, MSSA):

• Amoxicillin-clavulanate (875 mg/125 mg) PO q12h or

• Clindamycin 300 mg PO q6h or

• Doxycycline 100 mg PO q12h

Anaerobic bacteria:

See the list below:

• Amoxicillin-clavulanate (875 mg/125 mg) PO q12h or

• Clindamycin 300 mg PO q6h

Duration of therapy

For uncomplicated acute bacterial rhinosinusitis in adults, the recommended duration is 5-7 days.

For acute bacterial rhinosinusitis in children or in cases of severe infection in adults, an extended period of 10-14 days is recommended. ^[8]