Vonoprazan (Vono) is used to manage duodenal and gastric ulcers, reflux esophagitis, and pre
vention relapse. Its' a mechanism of action similar to proton pump inhibitors (PPIs), with a more 
rapid and prolonged acid-suppressive action, unaffected by diet and gene polymorphisms.      
This study assessed the therapeutic effect of Vono on Giardia lamblia in-vitro study as com
pared with metronidazole (MTZ). The study used five cultures of 10ml of medium each and were 
divided into: Culture I: medium only (positive control), culture II: inoculated with 104 trophozo
ites, culture III: inoculated with 104 trophozoites and treated with MTZ 50mg/ml, culture IV: in
oculated with 104 trophozoites and treated with Vono 50µm/ml, and culture V: inoculated with 
104 trophozoites and treated with the same of concentration both drugs. All cultures were subject
ed to trophozoites count and scanning electron microscope study. The mean number of trophozo
ites in all treated cultures: MTZ (MTZ), Vono, and combination cultures showed significantly de
creased compared to positive control. The mean trophozoite counts in both Vono culture and 
combination culture were significantly lower than that in MTZ culture. Also, the mean trophozo
ites count in combination culture was significantly lower than in Vono culture and MTZ culture. 
SEM showed marked destruction of trophozoites morphology in the combination group as con
trasted to the positive control group.