Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 3 2 2008 06 15 38 42 F Mohamadnezhad F Ghaffarifar A Dalimi 2015 10 03 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 µg/ml) of drugs at 37º for 4 h.  The IC50 estimated between 0.1 and 10µg/ml for metronidazole and 0.062 and 0.1 µg/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. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/60 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/60/59