What is antibiotics

In fact, many people are not unfamiliar with antibiotics, and are even very familiar with them. Many people's first reaction after suffering from a disease is to take some antibiotics. This will take effect very quickly and can relieve the pain of the disease. However, after taking it, it often causes more serious complications. Therefore, this is a drug that causes the greatest damage to people's healthy cells.

What are antibiotics?

Mechanism of action

There are four main mechanisms for the bactericidal effect of antibiotics: inhibiting the synthesis of bacterial cell walls, interacting with cell membranes, interfering with protein synthesis, and inhibiting the transcription and replication of nucleic acids.

How it works

(1) Inhibit cell wall synthesis

Inhibiting cell wall synthesis can cause bacterial cells to rupture and die. Antimicrobial drugs that work in this way include penicillins and cephalosporins. Mammalian cells do not have cell walls and are not affected by these drugs. The cell wall of bacteria is mainly peptidoglycan, and the organelle that synthesizes peptide chains is the ribosome, which is the only organelle of bacteria. However, frequent use can lead to increased bacterial resistance.

The achievement of this effect depends on a protein in the bacterial cell wall, usually called penicillin-binding protein (PBPs). β-lactam antibiotics can bind to this protein and inhibit the synthesis of the cell wall, so PBPs are also the target of this type of drug.

(2) Interaction with cell membrane

Some antibiotics interact with the cell membrane and affect the permeability of the membrane, which can have lethal effects on the cells. Antibiotics that act in this way are polymyxins and gramicidins.

(3) Interfering with protein synthesis

Interfering with protein synthesis means that enzymes necessary for cell survival cannot be made. Antibiotics that interfere with protein synthesis include the mycins (actinomycins), aminoglycosides, tetracyclines, and chloramphenicol.

(4) Inhibition of nucleic acid transcription and replication

Inhibition of nucleic acid transcription and replication Inhibition of nucleic acid function prevents cell division and/or synthesis of required enzymes. Antibiotics that work in this way include nalidixic acid and dichloroacridine.

In principle, the use of antibiotics should be selected based on the type of pathogen and its sensitivity to antibiotics.

1. Preventive medication

(1) Clean surgery is usually used only once before surgery, usually during induction of anesthesia. If the surgery is long or bleeding is heavy, a second dose may be given during surgery.

2. Treatment medication

(1) Treatment should be started after the pathogen has been identified as far as possible through culture, smear, serological examination, X-ray, etc. If it is a viral infection, antibiotics are not needed.

(2) Before the culture results are available, empirical medication can be determined based on symptoms, signs, routine blood biochemistry and imaging results, but sputum, blood or sterile secretions must be cultured before using antibiotics.

(3) The type of antibiotic depends on the condition of the patient. Mild cases can be treated orally or intramuscularly, while more serious cases can be given intravenously. Critically ill patients can use a combination of two antibiotics.

Antibiotics are generally used for 3 days. If there is no improvement, other antibiotics can be used instead. If the culture is positive and the patient is not sensitive to the antibiotic used, but the clinical condition improves, the antibiotic can be continued. If the cultured bacteria are sensitive to the drug but there is no clinical improvement, other sensitive antibiotics can be used instead.