Frank, I would strongly recommend using the dosage posted on LOL, some species of fish do not do well with higher dosage rates of Levamisole. See my comment below found in past discussion.
Ok just to make sure im dosing correctly im dosing 1.5 gram lev -= 1.5 1/4 teaspoons after 24 hrs large wc then wait 2 to 3 weeks and repeat. 150 gal tank
If for no other reason besides peace of mind can i do the Fenbendazole treatmemt first then the lev ?