How Do Antibiotics Work?

Antibiotics are also known as antibacterials and are medications that treat infections caused by bacteria. Bacteria are small organisms that can cause infection or illness like tuberculosis, syphilis, and salmonella. Our immune system can usually destroy the bacteria before they can multiply and cause symptoms of illness of infection. However, there are times when our bodies need a little extra help from antibiotics.

How Do Antibiotics Work?

There are different types of antibiotic, but they all work in several different ways:

For example, a bactericidal antibiotic (like Penicillin) can destroy the bacteria. A bactericidal typically either hinders the development of the bacterium's cell wall. Usually, a doctor will select an antibiotic based on the cause of the infection and which will best combat that type of bacteria.

What Are Antibiotics For?

Antibiotics are used to treat infections caused by a bacterium. Antibiotics can combat microorganisms like bacteria, parasites, and fungi. Still, they are not operative against viruses. This is because viruses are not considered microorganisms. It is important to know whether the infection is caused by bacteria or a virus. The majority of upper respiratory tract infections, like sore throats and the common cold are generally caused by viruses – antibiotics do not fight these viruses. In addition, if an antibiotic is used incorrectly or overused it is possible the bacteria will become resistant.

Types of Antibiotics

There are over 100 antibiotics, but most of them are made from only a few types of drugs. The following list consists of the main classes of antibiotics.

  • Penicillins–penicillin and amoxicillin
  • Cephalosporins — cephalexin (Keflex)
  • Macrolides — erythromycin (E-Mycin), clarithromycin (Biaxin), and azithromycin (Zithromax)
  • Tetracyclines — tetracycline (Sumycin, Panmycin) and doxycycline (Vibramycin)
  • Aminoglycosides — gentamicin (Garamycin) and tobramycin (Tobrex)
  • Fluoroquinolones — ciprofloxacin (Cipro), levofloxacin (Levaquin), and ofloxacin (Floxin)
  • Sulfonamides– co-trimoxazole (Bactrim) and trimethoprim (Proloprim)

The majority of antibiotics have two names. For example, the brand name, this was created by the manufacturer of the drug, and a generic name, which is based on the chemical structure of the antibiotic.

Side Effects of Antibiotics

The most common side-effects of antibiotics are:

  • Diarrhea
  • Fungal infections (yeast infections) of the digestive tract, mouth, and vagina

Rare side effects include:

  • Formation of kidney stones (caused from the use of sulphonamides)
  • Abnormal blood clotting (caused from the use of cephalosporins)
  • Sensitivity to sun (caused from the use of tetracyclines)
  • Blood disorders (caused from the use of trimethoprim)
  • Deafness (caused from the use of erythromycin and the aminoglycosides)

Allergic Reactions to Antibiotics

Antibiotic users might develop an allergic reaction – especially to penicillin. Common side effects are rashes, swelling of the face and/or tongue, and difficulty breathing. Doctors and pharmacists should be notified if you have ever experienced an allergic reaction to an antibiotic. Allergic reactions to antibiotics can be very serious and even fatal, which is referred to as anaphylactic reactions.

References

emedicinehealth.com: Antibiotics

medicalnewstoday.com: What Are Antibiotics? How Do Antibiotics Work?