Clarithromycin for Sinusitis and Pneumonia

Clarithromycin for Sinusitis

Inflammation of the sinuses rarely occurs without inflammation of the nasal mucosa. Therefore, rhinosinusitis is a more accurate term for what is commonly called sinusitis. The most common bacteria in acute bacterial sinus infection are Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, and Moraxella catarrhalis.

Clarithromycin is among first line antibiotics used to treat acute sinusitis. It achieves excellent mucosal levels but should be considered backup drugs.

Clarithromycin cures sinus infection in 80-90% of patients.

Dosage for sinusitis:

  • Children: 7.5 mg/kg every 12 hours for 10 days.
  • Adults: 500 mg every 12 hours for 14 days.

Clarithromycin vs Azithromycin for Sinusitis

Clarithromycin may be advantageous over azithromycin in eradicating some of the low-level resistant S. pneumoniae strains4.

Clarithromycin for Pneumonia

Pneumonia is a serious respiratory infection characterized by inflammation of the lungs. Community-acquired pneumonia (CAP) is a pneumonia acquired by a person outside a hospital or another health care facility.

Streptococcus pneumoniae causes up to 70% of community-acquired pneumonia cases, and atypical pathogens are responsible for 30-40% of cases.

Clarithromycin is recommended as the macrolide of choice for the treatment of pneumonia. Clarithromycin is very effective against Streptococcus pneumoniae and atypical pathogens such as Mycoplasma pneumoniae and Chlamydia pneumoniae, the most common bacteria responsible for pneumonia.

The success rate is about 82-95%1.

Dosage for pneumonia:

  • Children: 7.5 mg/kg every 12 hours for 10 days.
  • Adults: 250-500 mg every 12 hours for 7-14 days.

Clarithromycin vs Azithromycin for Pneumonia

Both antibiotics are similarly effective for pneumonia.

The study2 compared azithromycin (500 mg once daily for 3 days) and clarithromycin (250 mg twice daily for 10 days) in adult patients with mild to moderate community-acquired pneumonia. The groups did not differ with respect to clinical cure or bacteriologic response at the end of therapy (between days 12 and 16). A satisfactory clinical response was 94% in azithromycin-treated patients 95% in clarithromycin-treated patients. At day 19-23, only one patient in each treatment group had relapsed.

Another study3 compared single-dose azithromycin microspheres versus clarithromycin ER for the treatment of adults with mild-to-moderate community-acquired pneumonia. Clinical cure rates were 92.6% for azithromycin and 94.7% for clarithromycin ER.

See also


  • 1. English ML, Fredericks CE, Milanesio NA, et al. Cethromycin versus clarithromycin for community-acquired pneumonia. Antimicrob Agents Chemother. 2012 Apr;56(4):2037-47. PubMed
  • 2. O’Doherty B, Muller O. Randomized, multicentre study of the efficacy and tolerance of azithromycin versus clarithromycin in the treatment of adults with mild to moderate community-acquired pneumonia. Eur J Clin Microbiol Infect Dis. 1998;17:828-833.
  • 3. Drehobl MA, De Salvo MC, Lewis DE, Breen JD. Single-dose azithromycin microspheres vs clarithromycin ER for the treatment of mild-to-moderate community-acquired pneumonia in adults. Chest. 2005 Oct;128(4):2230-7. PubMed
  • 4. Margaritis VK, Ismailos GS, Naxakis SS, et al. Sinus fluid penetration of oral clarithromycin and azithromycin in patients with acute rhinosinusitis. Am J Rhinol. 2007 Sep-Oct;21(5):574-8.

Author: OriginalDrugs Team
Last reviewed: February, 2015

Quick facts

  • Clarithromycin generally is bacteriostatic.
  • It works by preventing bacteria from producing essential proteins. It doesn’t directly kill the bacteria, but leaves them unable to grow and multiply.