Clarithromycin
"I have just finished a 7 day course of 500mg tablets, twice a day for a chest infection which two other antibiotics failed to clear. This antibiotic worked much faster than others I have tried, with symptoms improving rapidly after just one day.

I had no side effects at all, not even the strange taste. My wife has also had a course of the same drug in the past, again with no side effects. 

Reading through these comments you would think that practically everyone has adverse side effects from this drug, but in actual fact it is a low percentage (under 10% according to the packet). I think more people tend to report bad side effects, than none hence the large number here. Don't be put off by this."