Clinafloxacin

Clinafloxacin (AM 1091) is a potent and broad-spectrum fluoroquinolone antibiotic, has inhibitory activity against gram-positive, gram-negative bacterias, and anaerobic pathogens in vitro^[1]. Clinafloxacin is against DNA gyrase and topoisomerase IV of S. aureus with IC₅₀ values of 0.92 μg/ml and 1.62 μg/ml, respectively^[2]. IC50 & Target:MIC: 1 μg/ml (parC-gyrA mutants,S. pneumonia)^[1] In Vitro: Clinafloxacin exhibits activity against S. pneumonia with an MIC of 1μg/ml for the parC-gyrA mutants^[2].
Clinafloxacin hydrochloride has antibacterial activities against target-altered mutant strains of S. aureus. It against Wild type S. aureus, gyrA mutant S. aureus and gyrA mutant S. aureus with MIC values of 0.016 μg/ml, 0.063 μg/ml and 0.915 μg/ml, respectively^[3].
In Vivo: Clinafloxacin is very effective for the therapy of penicillin-resistant, ciprofloxacin-susceptible pneumococcal meningitis in the rabbit model.
With the CS strain (2349)(Clinafloxacin MIC=0.12 μg/ml), at a dose of 10 mg/kg and 20 mg/kg per day Clinafloxacin achieves an initial reduction at 6 hr. Both are bactericidal at this point but presents regrowth at 24 hr, and the final reduction at 24 hr in mean log cfu/ml is 22.30 and 23.83, respectively. However, With the CR strain (4371)(Clinafloxacin MIC=0.5 μg/ml), Clinafloxacin even at 20 mg/kg per day does not decrease bacterial titers at any time point in this rabbit model of meningitis^[3].