Both nitazoxnide and metronidazole, which is typically used for anaerobic bacterial infections, target the same mechanism of action in parasites.
However, it’s important to know that nitazoxinide inhibits the pyruvate:ferredoxin oxidoreductase enzyme in parasites. On the other hand, metronidazole is dependent on upregulated activity of the same enzyme as it activates the drug inside of the cell.
By itself, it should be relatively effective, but it shouldn’t used in combination as it most likely won’t be synergistic.