Erythromycin
"Had a insect bite that got really badly infected on my calf to the point where I could barely walk it was that painful I was on penicillin but that did very little but after taking this it cleared up almost immediately. Although it's making feel quite nauseas where  all it takes is a buiscuit to make me want to throw up also having headaches and my heart beat keeps going fast but it worked a treat on my bite"