Clarithromycin
"I have only just started taking this tablet  and  feel a bit rubbish already, its  2am I have a vile horrid taste in my mouth, tried swilling my mouth with copius amounts of water, it does not work, stomach is making hideous gurgling noises and feel gassy but I do have a very sensitive stomach and I know this drug is going to cripple me. However my breathing seems a little itsy improved as docs say  I have whooping cough! I am on this for 10 days yet- 19 more big horrid  bulky tablets to suffer yet. "