Penicillin was first discovered in 1928 by Sir Alexander Fleming. After its discovery, scientists worked on it to discover its powers, and the first penicillin drug was produced only in 1940. This drug became an instant success because it seemed non toxic and also its high rate of activity and ever since, it has been used to combat a variety of diseases. It is usually taken orally or in injection form. The penicillin reaches the plasma, from where usually it is circulated to all parts of the body. Sometimes the penicillin may need to be made inactive. How do you achieve this? You can make penicillin inactive by one of three ways – by protein binding, by metabolism, or by excretion. Penicillin can be made inactive by liver metabolism, wherein the liver breaks down the drug into an inactive compound. This compound stops the penicillin circulation, and ensures it is flushed out of the body through excretion. Another way of making penicillin inactive is to filter it through the kidneys. However, this requires regulation of the drug quantity prescribed, to ensure there is uniformity in the amount of penicillin taken in and the amount being excreted. The third way of inactivating penicillin is to have the large plasma proteins bind themselves to the penicillin and render it inactive.