Clarithromycin
"So far I have only taken this for 3 days, it gives a foul taste in the mouth ( that comes through the body system and definitely not just from the tablet in the mouth) the horrible taste is there most of the time but worse for the few hours after you take the tablet, it did wake me up last night but I went back to sleep. I don't want to take them again.  I want to have a natural alternative next time, it does feel like a toxic drug, very unpleasant but sorry for those with the other dreadful side effects."