Metronidazole
"I have to say that metronidazole is a horrible antibiotic as far as side effects go especially when one has to go to work.  I experienced a lot of dizziness, migraines, muscle pain even in my heart, jittery and drowziness.  I'm sure flagyl is the same.  Next time I'm asking not to get this prescribed my doctor.  Better yet take it off the shelf."