Oral antibiotics are the simplest approach when effective, with intravenous antibiotics reserved for more serious cases.
Antibiotics can also be classified by the organisms against which they are effective and by the type of infection for which they are useful.
Antibiotics may sometimes be administered topically, as with eye drops or ointments.
Currently, it is estimated that greater than 50 percent of the antibiotics used in the U.S. are given to food animals (e.g.
Individual antibiotics vary widely in their effectiveness on various types of bacteria.
The production of antibiotics has been widespread since the pioneering efforts of Howard Walter Florey and Ernst Boris Chain in 1939.
At the highest level, antibiotics can be classified as either bactericidal or bacteriostatic.
Excessive use of prophylactic (preventive) antibiotics in travelers may also be classified as misuse.
Antibiotics have no effect on viruses, fungi, or parasites.
The importance of antibiotics to medicine has led to much research dedicated to the discovery and production of them.
Antibiotics can be categorized based on their target specificity: "Narrow-spectrum" antibiotics target particular types of bacteria, such as Gram-negative or Gram-positive bacteria, while "broad-spectrum" antibiotics affect a larger range of bacteria.
Human creativity is expressed in the ability to identify and process natural agents and synthesize new antibiotics.
Antibiotics are relatively harmless to the host, and therefore can be used to treat infections.
The term “antibiotic,” coined by Selman Waksman, originally described only those antibiotics derived from living organisms, in contrast to "chemotherapeutic agents," which are purely synthetic.
In certain settings, such as hospitals and some child-care locations, the rate of antibiotic resistance is so high that the normal, low-cost antibiotics are virtually useless for treatment of frequently seen infections.
A continuous race to discover new and different antibiotics results, in an attempt to keep from losing ground in the battle against infection.
Use or misuse of antibiotics may result in the development of antibiotic resistance in the infecting organisms, similar to the development of pesticide resistance in insects.
Antibiotics are produced industrially by a process of fermentation, where the source microorganism is grown in large containers (100,000–150,000 liters or more) containing a liquid growth medium.
Others simply lack advantage over the antibiotics already in use, or have no other practical applications.
The food animal and pharmaceutical industries have fought hard to prevent new regulations that would limit the use of antibiotics in food animal production.
Despite the wide variety of known antibiotics, less than one percent of antimicrobial agents have any medical or commercial value.
Taking antibiotics in inappropriate situations is another common form of antibiotic misuse.
Possible side effects to antibiotics are varied, and range from fever and nausea to major allergic reactions.
Antibiotics are generally small molecules with a molecular weight less than two thousand.
Modern research on antibiotics began in Britain with the discovery of penicillin in 1928 by Alexander Fleming.
Some antibiotics actually kill the bacteria (bactericidal), whereas others merely prevent the bacteria from multiplying (bacteriostatic) so that the host's immune system can overcome them.