I tryed everything to save my fish, tryed both the meds you mentioned, even as a last resort tryed the cat worming tablets nothing worked, saw the worms prutruding from the anus, there isn' always a cure for everything in life, not having ago don't wan't fishkeepers thinking that every med is going to cure them,i had to destroy two plecs managed to save the other one through stripping the tank down, most sites will tell you that internal parasites ae very hard to cure.