Effects of Tinidazole on Food Intake in Chinchillas (Chinchilla lanigera)

Abstract

Tinidazole is a second-generation nitroimidazole compound that is used as an antimicrobial to treat anaerobic bacterial and protozoal infections in humans and, less frequently, in veterinary medicine. However, metronidazole, another secondgeneration nitroimidazole, is more commonly used. Nonetheless, tinidazole has proven to be a superior therapy for parasitic infections in humans, particularly in the treatment of giardiasis. Furthermore, in chinchillas, metronidazole has been shown to cause a clinically relevant reduction in food intake after oral administration at published dosages. This study's objective was to evaluate the effect of orally administered tinidazole on food intake in healthy chinchillas. In 2 randomized, placebocontrolled, blinded, crossover studies, tinidazole was evaluated at 2 single high doses (100 mg/kg and 200 mg/kg PO, n = 9) and a repeated dosing schedule at a lower dose (20 mg/kg PO q12h for 10 doses, n = 12). Food intake was measured over 24-h periods before and after drug administration. The single-dose treatment groups both displayed significantly reduced food intake (200 mg/kg: –26 ± 21%; 100 mg/kg: –9 ± 21%, P < 0.01) as compared with the control group during the first 24 h after drug administration. Food intake returned to pretreatment values within 4-5 d. Repeated administration at 20 mg/kg q12h was not associated with any significant changes in food intake. No other adverse effects were noted during this study. Tinidazole administration at single higher doses resulted in an acute self-limiting reduction in food intake. In comparison, repeated administration of lower doses (20 mg/kg PO q12h) had no significant effects on food intake in healthy chinchillas. Therefore, tinidazole may be a more suitable drug for treating Giardia and anaerobic bacterial infections in this species than the more commonly used metronidazole.