Español
Português
Русский
العربية
한국어
日本語
Français
Deutsch
ภาษาไทย
How to Distinguish Mycins?
Erythromycin, chloramphenicol, and clindamycin are all called “mycins”. What are the differences in their effects?
There are many drugs with the word “mycin”, such as erythromycin, chloramphenicol, clindamycin, gentamicin, etc. are very common. So, how should these “mycins” be distinguished? How is the clinical application different?
Macrolide Antibiotics
Representative drugs: erythromycin, azithromycin, clarithromycin, clarithromycin, roxithromycin, telithromycin, etc.
Antibacterial spectrum: mainly against most Gram-positive bacteria, anaerobic cocci, and some Gram-negative bacteria.
Uses: To treat respiratory tract, urinary tract, skin and soft tissue infections and other diseases caused by Gram-positive bacteria and some Gram-negative bacteria, mycoplasma, Helicobacter pylori, sensitive bacteria, etc. In addition, erythromycin can be used to treat penicillin-resistant bacterial infections and is suitable for patients who are allergic to penicillin.
Lincomycin Antibiotics
Representative drugs: lincomycin, clindamycin, etc.
Antibacterial spectrum: mainly against Gram-positive bacteria, non-enterococci, some aerobic Gram-negative cocci and various anaerobic bacteria.
Uses: Treat acute and chronic osteomyelitis, joint infection, mixed infection of anaerobic and aerobic bacteria such as peritonitis, pelvic inflammatory disease, otitis media, sinusitis, etc. caused by Staphylococcus aureus.
Scope of application
Lincomycin, especially clindamycin, is superior to other drugs in the treatment of this infection, but it is easy to cause diarrhea and colitis.
Aminoglycoside Antibiotics
Representative drugs: streptomycin, neomycin, gentamicin, kanamycin, spectinomycin, etc.
Antibacterial spectrum: broad antibacterial spectrum, strong antibacterial activity against various aerobic Gram-negative bacilli including Pseudomonas aeruginosa; against penicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, methicillin-resistant epidermis Staphylococcus and other Gram-positive cocci also have good antibacterial effect. Some drugs are highly effective against Mycobacterium tuberculosis, but less effective against Gram-positive bacilli and Gram-negative cocci.
Uses: To treat systemic infections caused by sensitive aerobic gram-negative bacilli; to treat severe infections caused by gram-positive cocci should be combined with penicillin and other β-lactam antibiotics and rifampin. In addition, streptomycin can be used to treat tuberculosis.
Scope of application
It is mainly used for systemic infection caused by sensitive aerobic gram-negative bacteria. Especially for the common gram-negative bacteria such as Pseudomonas aeruginosa, Klebsiella and Escherichia coli, it has a long post-antibiotic effect (PAE), so it is used to treat serious infections caused by aerobic gram-negative bacteria, such as meningitis, respiratory tract infection, urinary tract infection, skin and soft tissue infection, gastrointestinal tract infection, burn infection and bone and joint infection. For severe infections caused by gram-negative bacilli such as septicemia, pneumonia, meningitis, etc., aminoglycosides alone may fail. At this time, other antibacterial drugs with strong antibacterial activity against gram-negative bacilli, such as broad-spectrum semi-synthetic penicillin, third-generation cephalosporins and fluoroquinolones, need to be used in combination.
Polypeptide Antibiotics
Representative drugs: vancomycin, norvancomycin, polymyxins, etc.
Antibacterial spectrum: narrow antibacterial spectrum, polymyxins are effective against some Gram-negative bacilli such as Escherichia coli, Klebsiella, Salmonella, Shigella and Pseudomonas aeruginosa. Vancomycin and norvancomycin have a strong bactericidal effect on Gram-positive bacteria, especially against Bacteroides fragilis and Clostridium.
Uses: Polymyxins can be used for topical treatment of Pseudomonas aeruginosa infection in ears, eyes, skin, mucous membranes and burns caused by sensitive bacteria, and for oral preparation before intestinal surgery. Vancomycin and norvancomycin can be used to treat serious infections caused by methicillin-resistant staphylococci, such as pneumonia, sepsis, endocarditis, osteomyelitis, and colitis.
Tetracycline Antibiotics
Representative drugs: tetracycline, oxytetracycline, aureomycin, demeclocycline, doxycycline, etc.
Antibacterial spectrum: broad antibacterial spectrum, including common gram-positive and gram-negative aerobic bacteria, anaerobic bacteria, rickettsia, spirochetes, mycoplasma, etc.
Uses: This class of drugs has special effects on the treatment of typhus and scrub typhus caused by rickettsia. It is the first choice medicine for inflammation, salpingitis and trachoma, etc. It also has good effect on plague, cholera, Brucellosis, granuloma inguinale, etc.
Clinical application
It is used for the clinical treatment of rickettsia disease, chlamydia disease, mycoplasma disease and spirochete disease. Doxycycline is generally the first choice in clinical practice.
Chloramphenicol Antibiotics
Representative drugs: chloramphenicol, thiamphenicol
Antibacterial Spectrum: Similar to Tetracycline.
Uses: Chloramphenicol can be used to treat severe infections such as typhoid fever, paratyphoid fever, and influenza bacillary meningitis caused by sensitive bacteria; it can be used locally to treat trachoma, conjunctivitis, and superficial ear infections. Thiamphenicol is mainly used clinically to treat typhoid, paratyphoid and other Salmonella infections.
Antibacterial range
Chloramphenicol has broad-spectrum antibacterial effect. Among aerobic gram-positive bacteria, they are sensitive to Streptococcus viridis, Diphtheria, Bacillus anthracis, Staphylococcus aureus, Streptococcus haemolyticus and Streptococcus pneumoniae, but relatively insensitive to Group D Streptococcus; Among aerobic gram-negative bacteria, it has good antibacterial effect on influenza bacteria, Shigella, pertussis, gonococcus and meningococcus, and is also sensitive to Salmonella, Escherichia coli, Proteus mirabilis, Vibrio cholerae, while it is not very sensitive to Serratia marcescens, Enterobacter and Klebsiella pneumoniae. Many anaerobic bacteria, including enterococcus, streptococcus, clostridium perfringens, clostridium, and bacteroides fragilis, can be inhibited by them. In addition, it is effective against most of rickettsia, chlamydia and mycoplasts, but has no inhibitory effect on Pseudomonas aeruginosa, indole-positive Proteus, tuberculosis, fungi, viruses and protozoa. After long-term clinical application of chloramphenicol, various kinds of bacteria can develop resistance to it to varying degrees, but the degree of resistance varies from place to time. The main mechanism of drug resistance is that the plasmid with drug resistance genetic gene in the bacteria mediates the production of chloramphenicol acetyltransferase, which acetylates the 3-hydroxy position of the propylene glycol gene in chloramphenicol. Therefore, chloramphenicol cannot bind with the 50S subunit of the bacterial ribosome and lose its activity. This drug resistance genetic gene can also be transferred to sensitive bacteria of the same or different genera through combination or translocation to make them become drug resistant bacteria. However, the strains that have acquired drug resistance can disappear and become sensitive bacteria again after stopping the drug for a period of time.
