So true, but if one is looking for a good starting point I think poultry pedia has the best list available. It's not perfect, but it's much better than most.
https://sites.google.com/a/poultrypedia.com/poultrypedia/medicine-chart
-Kathy
Yes, it is a decent list, most of which is accurate. For those using injectible Penicillin for the first time, there are very helpful steps in that process.