Clindamycin
"This antibiotic is brutal, but does its job.  I began it 3 days ago due to pericoronitis (infection at rear of wisdom tooth).  By the 3rd dose, the infection was basically gone.  It worked so quickly that I questioned if my body had killed off the bacteria, or if the antibiotic was really that powerful.

It's really that powerful.

Sadly, the side-effects are quite unpleasant, but an indicator that they are really working.  Fatigue, mild nausea, and lower abdominal issues seem to be quite common, and all three have hit me.  It's unpleasant to the point that I've more than once thought of stopping the treatment, but I know that's a bad idea.

It works really well...I just hope that I don't have to take it again for a very long time."