Telithromycin: a new ketolide antimicrobial for treatment of respiratory tract infections

Telithromycin is a new ketolide antimicrobial, specifically developed for t he treatment of community-acquired respiratory tract infections. It has a w ide spectrum of antibacterial activity against common respiratory pathogens including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella cata rrhalis and Streptococcus pyogenes. It also has activity against atypical p athogens, such as Chlamydia pneumoniae, Legionella pneumophila and Mycoplas ma pneumoniae. Telithromycin maintains activity against p-lactam and macrol ide-resistant respiratory tract pathogens and does not appear to induce cro ss-resistance to other members of the macrolide-lincosamide-streptogramin ( MLS) group of antimicrobials. It demonstrates bactericidal activity against S.pneumoniae and H. influenzae and has a prolonged concentration-dependent post-antibiotic effect (PAE) in vitro. The drug has favourable pharmacokin etics following oral administration. It is well absorbed, achieves good pla sma levels and is highly concentrated in pulmonary tissues and white blood cells. In clinical trials, telithromycin given orally at a dose of 800 mg o nce daily for 5 - 10 days was as effective as comparator antimicrobials for the treatment of adults with community-acquired pneumonia, acute exacerbat ions of chronic bronchitis, acute maxillary sinusitis and group A-P-haemoly tic streptococcal pharyngitis or tonsillitis. The adverse events and safety profile were similar to comparator antimicrobials. The most common adverse events were diarrhoea, nausea, headache and dizziness. Telithromycin shoul d provide an effective, convenient and well-tolerated once-daily oral thera py for treatment of respiratory infections.