I’m a person with a primary immunodeficiency who was infected years ago with giardiasis from my brother’s cat. Anyway, I have worked with an infectious disease specialist but to no avail. I still have it. I keep it in remission by eating a high fiber diet. It flares up from time to time. Is there any medication out to treat difficult giardiasis. I have tried everything under the sun. I heard that a woman with PI used a veterinary heart worm medication to get rid of it. She said it is not used anymore. Any ideas?