trichomoniasis
"I was prescribed 500mg of flagyl 2x a day for 7 days to cure my trichomoniasis. I can't tell you how happy I was to have the week over with. It made me depressed, anxious, and I was on vacation, which meant no alcohol while abroad, as alcohol interacts with the medicine severely. 



I should mention that I had researched the "no alcohol" warning quite a bit before my trip; I'm also on an anti-depressant, which is also contraindicated with alcohol, but doesn't actually cause a reaction in my experience. It would appear that some people can tolerate modest consumption of alcohol while on flagyl while the large majority fall ill. I made the mistake of ordering a glass of wine. Huge mistake. HUGE. The sickness wasn't worth it. At least I'm cured"