Flagyl Side Effects: I took flagyl twice in one day and that night my eyes became very http://www.medications.com/effect/view/37607 I took flagyl twice in one day and that night my eyes became very itchy and irritated, when I woke up the next day both of my upper eyelids were completely swollen. It was like I had been crying for days, what a weird side effect! But I talked to a pharmaci this happened to me too...about days after taking the med 2x per Fri, 16 Jan 2009 04:20:20 -0500 http://www.medications.com/effect/view/37607?item=16053 this happened to me too...about days after taking the med 2x per day i developed this little bump that i thought was a mosquito bite...it itched so bad, but then it got bigger and more red and itchy and 2 days later it went to the other other under eye... http://www.medications.com/effect/view/37607?item=16053