A STUDY OF THE PHOTOTOXIC POTENTIAL OF TROVAFLOXACIN IN BALB C MICE/

Trovafloxacin, a broad-spectrum naphthyridone antimicrobial agent, was evaluated for potential phototoxicity in a standardized in-vivo test system that has been used previously to assess quinolone antibiotics, Fasted BALB/c mice were given a single oral dose of either trovafloxac in mesylate (10, 30, 90 or 250 mg/kg) or the positive control lomeflox acin hydrochloride (71 mg/kg) and immediately exposed to long-wave ult raviolet (UVA) light. Animals were irradiated for 4 h, equal to a tota l UV light irradiation of approximately 18 J/cm(2). Before dosing, at the end of the irradiation period and at approximately 24, 48, 72 and 96 h after dosing, both ears of each mouse were evaluated for changes indicative of a positive response: erythema, oedema or a measurable in crease in ear thickness. Under the conditions of this study, trovaflox acin produced a mild response (erythema and a slight increase in ear t hickness) in mice given a dose of 90 or 250 mg/kg; no significant resp onse was observed in mice given either lower doses (10 or 30 mg/kg) or the vehicle. In contrast, 71 mg/kg of lomefloxacin produced a strong and persistent phototoxic response. The results of this study demonstr ate that the phototoxic potential of trovafloxacin is considerably les s than that of lomefloxacin and, when compared with similar studies wi th related compounds, suggest that trovafloxacin is among the least ph ototoxic of the fluoroquinolone class.