COMPARATIVE ASSESSMENT OF PRURIFLOXACIN, SPARFLOXACIN, GATIFLOXACIN AND LEVOFLOXACIN IN THE RABBIT MODEL OF PROARRHYTHMIA

• Published in: Journal of toxicological sciences Vol. 29; no. 1; pp. 63 - 71
• Main Authors: AKITA, Megumi, SHIBAZAKI, Yoshiaki, IZUMI, Masaaki, HIRATSUKA, Kazuyuki, SAKAI, Toki, KUROSAWA, Tohru, SHINDO, Yasuhiro
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Society of Toxicology 01.01.2004; Japan Science and Technology Agency
• Subjects: Animals; Anti-Infective Agents - toxicity; Arrhythmia; Blood Pressure - drug effects; Disease Models, Animal; Dose-Response Relationship, Drug; Long QT Syndrome - chemically induced; Long QT Syndrome - physiopathology; Male; QT interval; Quinolones; Quinolones - toxicity; Rabbit; Rabbits; Torsades de pointes; Torsades de Pointes - chemically induced; Torsades de Pointes - physiopathology
• ISSN: 0388-1350; 1880-3989
• DOI: 10.2131/jts.29.63

The administration of certain quinolone antibiotics has been associated with a prolongation of the QT interval on electrocardiogram, and in rare cases ventricular arrhythmias such as torsades de pointes. In this in vivo study using a rabbit arrhythmia model, we assessed the proarrhythmic effects and changes in the QT interval elicited by the administration of NM394 (UFX), an active metabolite of the new quinolone antibiotic prulifloxacin, and three representative quinolones, sparfloxacin (SPFX), gatifloxacin (GFLX) and levofloxacin (LVFX). Chloralose-anesthetized rabbits were co-administered a continuous infusion of methoxamine (15 μg/kg/min) together with NaOH (vehicle, 0.2 mol/L), SPFX (2, 3, 4 mg/kg/min), GFLX (4 mg/kg/min), LVFX (4 mg/kg/min) or UFX (4 mg/kg/min) via the ear vein, and then the effects on electrocardiogram were examined. SPFX and GFLX both prolonged the QT and QTc intervals. GFLX also induced premature ventricular contractions in all 6 rabbits that received it, and subsequently it induced torsades de pointes (TdP) in 3 of the 6 rabbits. SPFX infused at the dose of 4 mg/kg/min induced conduction blocks without inducing TdP, whereas that infused at the lower dose of 3 mg/kg/min induced both conduction blocks and TdP. The infusions with LVFX and UFX did not elicit remarkable prolongations in the QT interval, and none of the animals infused with the agents developed arrhythmia. These findings suggested that LVFX and UFX were less potent than SPFX and GFLX in prolonging the QT interval and inducing life-threatening arrhythmias.