Introduction of Antibiotics

In modern medicine, antibacterial drugs play a vital role. They help humans fight against various bacterial infections and save countless lives. This article will give you a detailed introduction to antibacterial drugs. 1. Definition and classification of antibacterial drugs refer to drugs that can kill or inhibit the growth of bacteria. According to their different chemical structures and mechanisms of action, they are mainly divided into the following categories: penicillins: such as penicillin G, amoxicillin, etc. This class of drugs works against bacteria by disrupting the synthesis of their cell walls. It has a good antibacterial effect on Gram-positive bacteria, and some varieties also have a certain effect on Gram-negative bacteria. Cephalosporins: divided into four generations. The first generation cephalosporins are mainly used for the treatment of gram-positive bacterial infections; the second and third generation cephalosporins are increasingly effective against gram-negative bacteria; and the fourth generation cephalosporins have broad-spectrum antibacterial activity. Macrolides: such as erythromycin, azithromycin, etc. It acts mainly by inhibiting the synthesis of bacterial proteins. It has good antibacterial effect on Gram-positive bacteria, mycoplasma, chlamydia, etc. Aminoglycosides: such as gentamicin, amikacin, etc. The mechanism of action is also inhibition of bacterial protein synthesis. It has a strong antibacterial effect on Gram-negative bacteria, but has a certain degree of nephrotoxicity and ototoxicity. Tetracyclines: such as tetracycline, doxycycline, etc. It also plays an antibacterial role by inhibiting the synthesis of bacterial proteins. However, its application has been limited in recent years due to the increase of drug-resistant bacteria. Fluoroquinolones: such as norfloxacin, levofloxacin, etc. The mechanism of action is to inhibit the DNA gyrase of bacteria, thus hindering the replication of bacterial DNA. Has broad-spectrum antibacterial activity, good oral absorption, and convenient use. 2. Mechanism of action of antibacterial drugs Antibacterial drugs work mainly in the following ways: Inhibit the synthesis of bacterial cell wall: Bacterial cell wall is an important part of maintaining bacterial morphology and protecting the internal structure of bacteria. Drugs such as penicillins and cephalosporins can interfere with the synthesis of bacterial cell wall, resulting in the defect of bacterial cell wall, the increase of osmotic pressure in cells, and eventually the rupture and death of bacteria. Affect the permeability of bacterial cell membrane: Some antibacterial drugs can destroy the structure of bacterial cell membrane, increase the permeability of cell membrane, and cause the outflow of substances in bacterial cells, thus leading to the death of bacteria. Inhibition of bacterial protein synthesis: Proteins are essential for bacterial life activities. Drugs such as macrolides, aminoglycosides and tetracyclines can act on the ribosomes of bacteria and inhibit the synthesis of bacterial proteins, thus achieving the purpose of antibacterial. Inhibition of bacterial nucleic acid synthesis: Fluoroquinolones and other drugs can inhibit bacterial DNA gyrase, hinder the replication of bacterial DNA, thereby inhibiting the growth and reproduction of bacteria. 3. Rational use of antibiotics and strict control of indications: antibiotics are not panaceas and should only be used when bacterial infection is identified. For viral infections, such as common cold and influenza, the use of antimicrobial drugs is not only ineffective, but also may lead to the emergence of bacterial resistance. Selection of appropriate antibiotics: The selection of appropriate antibiotics should be based on the location of infection, the type of pathogens, the age of patients, underlying disease and other factors. Before using antibiotics, it is better to carry out pathogenic bacteria culture and drug sensitivity test to guide clinical medication. Master the correct dosage and course of treatment: too small dosage may not achieve the therapeutic effect, and too large dosage may increase the risk of adverse reactions. If the course of treatment is too short, it will easily lead to the recurrence of infection, and if the course of treatment is too long, it may lead to the emergence of bacterial resistance. Therefore, antibiotics should be used strictly in accordance with medical supervision, and the dosage should not be increased or decreased or the course of treatment should not be shortened. Avoid drug combinations: In general, avoid unnecessary drug combinations as much as possible. Combined use of drugs may increase the risk of adverse reactions and easily lead to the emergence of bacterial resistance. However, in some cases of severe infection or unknown pathogens, antibiotics can be used in combination according to the needs of the patient’s condition. Pay attention to the medication of special groups: the elderly, children, pregnant women, lactating women and other special groups should pay special attention to the use of antibiotics. The dosage of antibiotics should be adjusted according to the renal function of the elderly with renal hypofunction.Children whose liver and kidney functions are not fully developed should choose antibiotics with less impact on liver and kidney functions.Pregnant and lactating women should avoid the use of antibiotics with adverse effects on the fetus or infant. 4. Adverse reactions of antibiotics Antibiotics may also cause some adverse reactions while treating diseases, mainly including the following aspects: Allergic reactions: such as rash, pruritus, expiratory dyspnoea, etc. Severe allergic reactions can lead to anaphylactic shock, which is life-threatening. Gastrointestinal reactions: such as nausea, vomiting, diarrhea, etc. Liver and kidney damage: Some antibacterial drugs may cause damage to the liver and kidney, manifested as abnormal liver function, renal dysfunction, etc. Nervous system reactions: such as headache, dizziness, insomnia, convulsions, etc. Double infection: Long-term use of broad-spectrum antibiotics may lead to imbalance of normal flora in the body, causing double infection, such as fungal infection. 5. The emergence of bacterial resistance and countermeasures With the widespread use of antibiotics, the problem of bacterial resistance is becoming more and more serious. Bacterial resistance refers to the ability of bacteria to resist a certain antibacterial drug, which makes the therapeutic effect of the drug on bacteria reduced or ineffective. Bacterial drug resistance is mainly caused by the following reasons: irrational use of antibiotics: such as no indications, inadequate dosage, too short course of treatment, frequent replacement of drugs and so on. Mutation of bacteria themselves: Bacteria may have genetic mutations in the process of growth and reproduction, resulting in drug resistance. Route of transmission: Drug-resistant bacteria can be transmitted through person-to-person contact and contamination of medical devices. In order to deal with the problem of bacterial resistance, we can take the following measures: rational use of antibiotics: strictly grasp the indications, select the appropriate antibiotics, master the correct dosage and course of treatment, and avoid combined use of drugs. Strengthen the management of antibacterial drugs: establish and improve the management system of antibacterial drugs, and strengthen the supervision of the approval, procurement and use of antibacterial drugs. Research and development of new antibacterial drugs: increase investment in research and development of new antibacterial drugs, and search for new targets and