The fluoroketolide solithromycin is 2-fold more potent in vitro than telithromycin against pneumococci (including macrolide-resistant strains) and Haemophilus influenzae and very active on pathogens causing atypical pneumonia. In contrast, it is a 30-fold less potent inhibitor of nicotinic receptors incriminated in telithromycin toxicity. In Phase II/III trials, oral solithromycin once-daily (800 mg on day 1; 400 mg on days 2-5) proved effective and safe when compared to respiratory fluoroquinolones for the treatment of community-acquired bacterial pneumonia (CABP). A Phase III intravenous trial vs. moxifloxacin has been recently completed for the same indication. Solithromycin may restore interest in ketolides as a first-line therapy for CAPB. Solithromycin safety should nevertheless be confirmed in larger populations allowing for detection of rare adverse events.
Keywords: Chlamydophila pneumoniae; Haemophilus influenzae; Legionella pneumophila; Mycoplasma pneumoniae; Streptococcus pneumoniae; community-acquired bacterial pneumonia; ketolide; levofloxacin; moxifloxacin; solithromycin.