I had a very bad reaction to taking metronidazole for only three days and now one month later still lingering issues. The only other medication I take is effexor for many years. Now I find out that the two can have a drug interaction that is not listed on it or was advised to me from the pharmacy or dr who gave it to me. The first couple days had crazy mood swings and irritability, by the third day had crazy vertigo, dizziness and nausea , mood changes, depression, which even though stopped the medication has lingered. I felt like it was slowly getting better real slow but then I missed one effexor pill and felt symptoms all over again. I see both of these meds may cause seratonin syndrome and metronidazole can cause neurological problems. Has anyone had a similar problem? Did or when did it get better? And how? This has been the worst experience of my life. Thanks Melissa