In Vitro Effects of Metronidazole and Albendazole on Giardia lamblia Isolated from Iranian Patients

Background: The aim of the present study was to evaluate the effects of metronidazole and albendazole against clinical isolates of Giardia lamblia in vitro. Methods: From all human samples of containing cysts, 10 isolates were successfully excysted in vitro. Trophozites viability was assessed by eosine 0.1% and cultured axenically in TYI-S-33 modified medium supplemented with heat inactivated bovine serum 10%. All cultures were incubated in 37°C for 24-48 h. After this time trophozoites were exposed to different concentration (0.05, 0.1, 2, 10, 50 jug/ml) of drugs at 37° for 4 h. The IC50 estimated between 0.1 and lO^g/ml for metronidazole and 0.062 and 0.1 jig/ml for albendazole. Results: Eight isolates were found susceptible to the metronidazole while all isolates were found susceptible to the albendazole. Statistical results indicated that there was significant difference (P 0.05) in the sensitivity to metronidazole and albendazole in all isolates. Conclusion: The killing affects of albendazole on G. lamblia was greater than metronidazole.