The first sulfonamide and the first systemically active antibacterial drug, Prontosil , was developed by a research team led by Gerhard Domagk in 1932 or 1933 at the Bayer Laboratories of the IG Farben conglomerate in Germany,    for which Domagk received the 1939 Nobel Prize in Physiology or Medicine.  Sulfanilamide, the active drug of Prontosil, was not patentable as it had already been in use in the dye industry for some years.  Prontosil had a relatively broad effect against Gram-positive cocci , but not against enterobacteria . Research was stimulated apace by its success. The discovery and development of this sulfonamide drug opened the era of antibacterials.  
Antibiotics, particularly those in the penicillin and sulfa groups, are the most common cause of drug allergies.  Most drug allergies are usually limited to hives, swelling, and skin rashes, but some people experience rare and life-threatening reactions, called anaphylaxis.  Drug allergies are caused by your immune system mistaking the antibiotic for a foreign substance, inflaming your skin or, in more severe cases, restricting airways and causing shock, which can lead to unconsciousness or death.  If you experience the symptoms of anaphylaxis, it's crucial that you seek medical help immediately, as it is a medical emergency. Learning how to treat skin rashes and recognize the signs of a more severe reaction can help you feel your best, and could save your life.
Shake the drops gently to be sure the medicine is well mixed. Tilt your head back slightly and pull down on your lower eyelid. Position the dropper above your eye. Look up and away from the dropper. Squeeze out a drop and close your eye. Apply gentle pressure to the inside corner of your eye (near your nose) for about 1 minute to prevent the liquid from draining down your tear duct. If you are using more than one drop in the same eye, repeat the process with about 5 minutes between drops. If you are using drops in both eyes, repeat the process in the other eye.