antibiotics online

Important Types of Antibiotics

It is true that there are over a hundred types of antibiotics in use today. However, most of them are made up of a few drug types:

  1. Penicillins: in amoxicillin and penicillin
  2. Cephalosporins: in Keflex and cephalexin
  3. Macrolides: in E-Mycin, Biaxin, and Zithromax
  4. Sulfonamides: in co-trimoxazole
  5. Fluoroquinolones: in Cipro, Levaquin, and Floxin
  6. Aminoglycosides: in gentamicin
  7. Tetracyclines: In Sumycin, Panmycin, and Vibramycin.

It should not be strange that most of the antibiotics usually have two names - the generic name from the antibiotic chemical component, and the brand name imposed by the manufacturing company.

The generic names are usually not capitalized (amoxicillin and penicillin), while the brand names are capitalized (E-Mycin, Biaxin, and Zithromax).

Each drug type is strictly effectively recommended for certain infections types. The best person to ascertain if you need any of these drugs is your doctor - after a diagnosis.  It is, however, possible for one to have a series of known allergies that eliminates the possibility of him consuming certain classes of antibiotics. For example, if the doctor understands a person is allergic to Fluoroquinolones, then he would not prescribe Levaquin.

Classes and history of antibiotics

There is a wide range of antibiotic classes available, and these also determine their mode of usage and mechanism of action.


This is a wide class of antibiotics and the first to be noticed in this group was penicillin. Alexander Fleming discovered it in 1928. They all have a beta-lactam ring, and they operate by altering peptidoglycan synthesis. Examples include: penicillins (amoxicillin, cephalosporins), they are used mostly as anti Gram-positive bacteria.


In this class, prontosil was the first developed antibiotic commercially available. This was developed in 1932. They are all broad-spectrum antibiotics that inhibit the synthesis of the vitamin B foliate bacteria. They can act both on Gram-negative and Gram-positive bacteria, thus diminishing the bacteria production and growth.

Sulfonamides are not used often in recent time, because of bacterial resistance development and unwanted hepatotoxicity effects.


This antibiotics class is more effective as anti Gram-positive bacteria; more like the beta-lactams. Moreover, they operate in such a way that does not allow for the reproduction and growth of bacteria. They inhibit the synthesis of protein.

They are more effective in certain ways than penicillins, and they are applicable against specific bacteria classes that penicillin cannot cure. This class has been seen to be the second most commonly prescribed.


This is a class that also inhibits protein synthesis in bacteria and causes the cell to die. This class is effective only against certain Gram-positive and Gram-negative bacteria. However, they are not absorbed by digestion, and as a result, it must be administered via injection.

Streptomycin was the first ever drug found to be effective against tuberculosis. Moreover, its usage in present day is very limited because of aminoglycosides toxicity issues.


These are broad-spectrum antibiotics that are effective against Gram-negative and Gram-positive bacteria. They also act like the sulfonamides by inhibiting reproduction and growth of bacteria through protein synthesis.

Due to the increase of resistance of bacteria, the use of tetracyclines is reducing. Moreover, they are still very much effective for treating urinary and respiratory tract infections, acne, and also chlamydia infections. They are usually taken two hours after or before eating because they are seen to bind easily with food and this reduces the absorption.


This is a class that appears to be the most recent and was discovered in 1987. They are effective against Gram-positive bacteria. The most commonly used in the class is Daptomycin with a unique operation mechanism; cell membrane function disruption in several aspects. This operation mechanism proves to be beneficial; because bacterial resistance to this drug is rare even though there have been a few cases. Commonly used to treat skin and tissue infections, and it is administered via injection.


The first marketed in this class is Linezolid, which was approved for use in 2000. These antibiotics are active against Gram-positive bacteria and they operate in a way to inhibit reproduction and growth in bacteria by inhibiting the synthesis of protein.

Cycloserine has, however, been seen to be in use since 1956 for treating tuberculosis. Its resistance has been seen to be relatively slowly developing since its introduction.


Application of antibiotics

It is highly recommended to administer antibiotics prior to a prescription from your doctor. However, the likely conditions for the administration of antibiotics include:

  • Conditions that have been diagnosed not to be extreme, but are not likely to heal up without taking antibiotics. The example includes acne.
  • Conditions proven that antibiotics would hasten recovery in the patient. The example includes infection of the kidney.
  • Conditions not extremely serious, but would be transmitted to others except antibiotics are used. Examples include impetigo (infection of the skin), or chlamydia (sexually transmitted infection).
  • People that are at risk of getting infected by bacteria: babies less than 72 hours old, people over 75 years old, people with heart failure, and people with weak immune system.