Levofloxacin reduces formalin-induced nociception in rats

Fluoroquinolones comprises a variety of antibacterial drugs that have been used since several years ago for the treatment of respiratory, gastrointestinal, ophthalmological, urinary, skin, and other soft tissues infections. Additional to their antibacterial effects, some reports have suggested that certain fluoroquinolones have analgesic properties that may have an additional benefit for the treatment of patients with painful infections. One of these drugs is levofloxacin, a third-generation fluoroquinolone, which has demonstrated analgesic properties in animal and human pain models. In order to expand this knowledge, the aim of this study was evaluate the antinociceptive properties of levofloxacin on formalin-induced nociception in rats. Female Wistar rats (200-250 g) were injected with 50 μL of diluted formalin (1%) into the dorsal surface of right hind paw. Nociceptive behavior was quantified as the number of flinches of the injected paw. Reduction of flinching was considered as antinociception. Our results showed that levofloxacin administered orally is able to produce an antinociceptive effect in a dose dependent manner in the rat (10-100 mg/kg) which is in agreement with previous reports using different models of pain. In order to elucidate the mechanism of action by which this drug produces its effects, further studies are warranted.