作用于革兰氏阳性菌的抗生素（An antibiotic that acts on Gram-positive bacteria）

1、作用于革兰氏阳性菌的抗生素（An antibiotic that acts on Gram-positive bacteria）character this product is an organic acid, insoluble in water and soluble in organic solvents. Sodium (or potassium) salts are commonly used in clinic to enhance their solubilitystability the nature of the product is unstable. The beta

2、lactam ring is the most unstable part in the structure of the compound. Under the condition of acid, alkali or beta lactamase, it is easy to hydrolyze and open ring and lose its antibacterial activitypropertiesThe non alkaline cracking was D- and penicillium.? not acid at pH=2, decomposition of Peni

3、cillium acid; in pH=4, decomposed into penicillenic acid, the molecular rearrangement formation of Penicillium acid, in strong acid condition or mercuric chloride lysis of D- penicillamine and penilloaldehyde. So penicillin cant be taken orally.Penicillin, or Staphylococcus aureus, or some other bac

4、teria, produces a substance called beta lactamaseRing opening of the beta lactam ring loses its antibacterial activity. This is the reason why bacteria are resistant to penicillinPenicillin can not be taken orally, whether it can be prepared into water injection for medical use?May not。Because the b

5、eta lactam ring in penicillin structure is very unstable, it is easy to hydrolyze and open the ring to lose the antibacterial activity. Therefore, it is often made into powder injection, and Sterile Water for Injection is used now before injectionresistanceRole of bacteriaMost gram positive bacteria

6、, such as hemolytic streptococcus, pneumococcus, green Streptococcus, etc.;Gram negative cocci, such as Neisseria meningitidis and susceptible Neisseria gonorrhoeae;Let gobacteriumThe pathogenic Leptospira, such as Treponema pallidum and leptospira.?Antibacterial action and clinical selection?Penici

7、llin, the same as penicillin, blocks the synthesis of peptide bound to cells and binds to different penicillin binding proteins on the cell membraneIt is effective for gram positive cocci, gram negative cocci (except enterococci), gram positive bacilli, gram negative bacilli (except Pseudomonas aeru

8、ginosa).Antibacterial action and clinical selection1., these drugs can inhibit intestinal bacteria synthesis of vitamin K, so during the period of medication may be complicated by bleeding, this drug should not be combined with anticoagulants, NSAIDs anti-inflammatory drugs, because it can increase

9、the risk of bleeding. The bleeding tendency should be observed during the period of medication.Adverse reactions and application attention1., these drugs can inhibit intestinal bacteria synthesis of vitamin K, so during the period of medication may be complicated by bleeding, this drug should not be

10、 combined with anticoagulants, NSAIDs anti-inflammatory drugs, because it can increase the risk of bleeding. The bleeding tendency should be observed during the period of medication2. drugs are toxic to renal function, we should observe the change of renal function. It should not be combined with am

11、inoglycosides and diuretics (especially the first generation preparation), so as not to increase nephrotoxicity or decrease serum concentration. The urine protein and blood urea nitrogen should be detected regularly, and the urine volume and urine color should be observed.3., the conventional drug d

12、oes not do allergy test, but allergic to penicillin patients, you need to do allergy test.4. avoid alcohol and alcoholic beverages with the same service, otherwise it will cause dyspnea, tachycardia, abdominal spasm, nausea, vomiting and other adverse reactions.(three) the head of the fungus1. antim

13、icrobial spectrum is similar to the second generation cephalosporin2. of the ESBL producing strains were effective3. is effective for some anaerobesCefazolin?:Cefoxitin?(four) carbapenem antibioticsImipenem (imipenem) has a certain antibacterial effect on Gram negative bacteria (PAE), and has no cro

14、ss resistance to the third generation cephalosporin, and is stable to most of the lactamase. The combination of 1:1 and the inhibition of renal dehydrogenase was effective in the treatment of acute pancreatitis (P 0.(five) single loop antibioticsAztreonam?:Stabilization of beta lactamaseIt has a str

15、ong effect on G- bacteriaResistance to various G+ and anaerobic bacteriaLess adverse reactions(six) - lactamase inhibitorsClavulanic acid (clavulanic acid), Shubatan, tazobactamThere is no or only very weak antibacterial activity of the lactamase inhibitor, but it can inhibit the enzyme protection a

16、nd increase the synergism with other lactam antibioticsSeveral kinds of lactam - lactamase inhibitorsAmpicillin sulbactam?Clavulanic clavulanic acidPiperacillin tazobactam?Cefoperazone sulbactam?Two. Aminoglycoside antibioticsThe activity of G- was high;The effect on G- coccus is poor;The effect of

17、G+ was weaker, but Staphylococcus aureus was more sensitive;Anaerobic bacteria are often ineffectiveTwo. Aminoglycoside antibioticsRarely absorbed orally, the half-life is short.2, such drugs mainly on G- Bacillus powerful.3. Bacteria are prone to produce inactivation enzymes and drug resistance4, b

18、eta lactam antibiotics can reduce the antibacterial activity of gentamicinTo avoid the simultaneous infusion of two drugs in the same infusion bottle, and avoid and efficientlyDiuretics (antihistamines and strengthen ototoxicity) (conceal ototoxicity)Share。Adverse reactionNephrotoxicityOtotoxicityne

19、urotoxicitySuperinfectionOccasional hypersensitivity reactionVestibular dysfunction toxicity order: gentamicin tobramycin netilmicin Amikacin kanamycin.Cochlear nerve damage degree of order: gentamicin tobramycin Amikacin kanamycin netilmicin.Example analysisAnalysis: unreasonable. If the penicillin

20、 and gentamicin were dripped in the same infusion, two drugs were mixed, and the former beta lactam ring could be connected with the amino sugar of the latter, and the latter was inactivated. Similar results were obtained when the mixture of beta lactam and aminoglycoside antibiotics was mixed in vi

21、tro. Intramuscular injection of beta lactam antibiotics and aminoglycoside antibiotics can be used if the clinical needs to be combinedMain characteristics of commonly used drugsStreptomycin is often used as the first choice for tuberculosis, plague, Escherichia coli, Pasteurella multocida and lepto

22、spirosis. Susceptible to drug resistance.Amikacin is slightly stronger than streptomycin, and is used for colibacillosis, salmonellosis, Staphylococcus aureus, infectious rhinitis and so on. Invalid for bacillus.Gentamicin: aminoglycoside antibiotics have the strongest antibacterial activity. Drug r

23、esistance is not as good as that of generic drugs.Neomycin: the strongest effect on Pseudomonas aeruginosa, the most toxic in aminoglycosides.Apramycin: is the preferred treatment of colibacillosisThree. Macrolide antibioticsFunction characteristicsIt has a strong effect on G+ bacteria, Mycoplasma p

24、neumoniae and Chlamydia trachomatis.Its not just anti-inflammatory. Erythromycin can be used as the first choice for Legionella disease, Campylobacter caused septicemia or enteritis, mycoplasma pneumonia, Chlamydia trachomatis induced pneumonia and colitis.=?Clinical useAs for gram positive cocci to

25、 penicillin resistant (especially staphylococcus aureus) infections.This product is the drug of choice for the following: the infection of Legionella pneumonia, Mycoplasma pneumonia. Diphtheria or diphtheria carriers, Chlamydia trachomatis caused neonatal conjunctivitis, infantile pneumonia, Campylo

26、bacter caused septicemia or enteritis; also can be used for long-term prevention of rheumatic fever and endocarditis prevention.This product as a substitute for penicillin allergic patients following infection: Streptococcus pyogenes, pneumococcal infection caused by streptococcus; scarlet fever, ce

27、llulitis; treatment of anthrax, gas gangrene, actinomycosis etc.Three. Macrolide antibioticsErythromycinThe antibacterial spectrum is similar to penicillin, but it is not as good as penicillin. It is used in penicillin allergy animals and various infections caused by penicillin resistant Staphylococ

28、cus aureus and other sensitive bacteria. Also used in eye ointment or ointment or skin infections.Amphotericin BErythromycin resistant Staphylococcus aureus is effective. For most gram positive bacteria, the effect is less than erythromycin. Mainly used in the treatment of mycoplasma infection in pi

29、gs and chickens. As feed additive.TylosinSpecial antibiotics for animals. Mycoplasma disease is one of the most powerful drugs in macrolides.It can be used as feed additive.Test starSpecial antibiotics for animals. Of Actinobacillus pleuropneumoniae, Pasteurella multocida and Mycoplasma was stronger

30、 than tylosin.AzithromycinAntimicrobial activity (against G- bacteria) erythromycin (Mycoplasma pneumoniae)2. acid resistance, oral absorption easily, widely distributed, high tissue concentration3. t1/2 long (3548hr)Most of the 4. parts are excreted by feces5 most resistant to Mycoplasma pneumoniae

31、 (similar drugs).6 main treatment of respiratory tract and soft tissue infection.Four. Tetracycline antibioticsCharacteristicIt is a broad-spectrum antibiotic and a fast acting bacteriostatic agent.Most of the G+ and G-, four effective, ineffective against Pseudomonas aeruginosa. Antibacterial activ

32、ity of penicillin can be interfered.Antibacterial activity: doxycycline Oxytetracycline Tetracycline chlortetracyclineContinuous low concentration administration can promote the growth of animals.Adverse reactionCan cause intestinal flora disorder;Influence on tooth and bone development;Liver, kidne

33、y toxicity and cardiovascular toxicity;Easy to penetrate the placenta and enter the milk;Two valence metal ions affect its absorption;Cross resistance exists in natural tetracycline drugsFive, Lin Ke amine antibiotic1. in vivo processClindamycin has good oral absorption, high bioavailability and lit

34、tle effect on foodThe bone tissue concentration is high, which can penetrate the placental barrier, but not through the normal BBBIt can be excreted through bile, but the urine is low3. mechanism of actionIt can bind to the 50S subunit of bacterial nuclear protein, inhibit peptide acyltransferase, block the elongation of peptide chain and inhibit the synthesis of bacterial protein. Two drugs compete with erythromycin and chloramphenicol for the same binding site, so they are not suitable for