In common usage, an antibiotic is a substance or compound that kills bacteria or inhibits their growth. Antibiotics belong to the more common group of antimicrobial compounds, used to treat infections caused by microorganisms, including fungi and protozoa. Most antibiotics are now semisynthetic, thanks to medicinal chemistry. They are modified chemically from original compounds found in nature. In addition to this origin-based classification into natural, semisynthetic, and synthetic, antibiotics may be divided into two broad groups according to their effect on microorganisms: those that kill bacteria are bactericidal agents, and those that only impair bacterial growth (also known as bacteriostatic agents).
Antibiotics are usually classified from their mechanism of action, spectrum of activity, or chemical structure. Most antibiotics target bacterial functions or growth processes. Antibiotics that target the bacterial cell wall, or cell membrane, or interfere with essential bacterial enzymes are usually bactericidal in nature, while those that target protein synthesis are usually bacteriostatic. Broad-spectrum antibiotics affect a wide range of bacteria while narrow-spectrum antibiotics target particular types of bacteria.
The process of production of antibiotics usually involves the screening of wide ranges of microorganisms, and their testing and modification. Production is carried out using fermentation, usually in strongly aerobic form.
Consumption
Oral antibiotics are simply ingested, while intravenous antibiotics are used in more serious cases, such as deep-seated systemic infections. Antibiotics may also sometimes be administered topically, as with eye drops or ointments.
Side effects
Although antibiotics are generally considered safe and well tolerated, they have been associated with a wide range of adverse effects. Adverse effects can range from fever and nausea to major allergic reactions including photodermatitis and anaphylaxis. One of the more common side effects is diarrhea, which results from the antibiotic disrupting the normal balance of the intestinal flora. Other side effects can result from interaction with other drugs, such as elevated risk of tendon damage from administration of a quinolone antibiotic with a systemic corticosteroid.
Majority of studies indicate that antibiotics do not interfere with contraception. Interactions between alcohol and antibiotics are vary from one specific antibiotic to another, and in some cases can cause severe side effects and seriously decrease effectiveness of antibiotics.
