Azithromycin
"My young son was presciribed this for severe tonsillitis. His fevers were very high. Paracetamol would bring it down but it would be right back up long before 4 hrs were up. The Azithromycin just made him sicker. He had the worst diarrhea and gas and abdominal pain which was very difficult for an already miserable child. After 3 days he wasn't improving and was changed to a different medication."