No, the furazolidone didn't cause any noticable side effects. It's the smaller of the 3 pills (flourescent yellow). Being on 4 different drugs wasn't fun. I did have some nausea (OK lots) but I discovered early on it can be controlled with diet. It's hard to say which of the 4 caused the nausea or which symptom.
If you've read my other posts these drugs (not sure which one) causes 'horrible' muscle fatigue. Typing, eating, brushing teeth is so hard - your muscles give out. Again, this can be fixed with electrolytes.
So these drugs do cause side effects...but it's hard to say which one.
When I say furazolidone didn't cause anything, I mean anything hurtful to the body. As you know you can't eat certain foods on Furazolidone. If you avoid those foods you can prevent those issues with the drug.