Ampicillin

Ampicillin is an antibiotic which, although chemically similar to penicillin, works on a much broader range of bacteria. It has been widely used since 1961 and is now one of the most commonly prescribed antibiotics. Like penicillin, it can cause an allergic reaction, but it is not very toxic in humans and has few other side effects. It works by preventing bacteria from forming a cell wall. 
Ampicillin can be used for a variety of common infections, but some types of bacteria are resistant, most notably Pseudomonas. 
Ampicillin at Wikipedia
Category:Pharmaceuticals