Basics of antibiotics-different types of classification

Basics of antibiotics

1. Antibiotics basics Biotics lab

2. MICROBIOLOGY AND INFECTIONS Biotics lab

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9. Antibiotics MOA Biotics lab

10. ACTIVITY BACTERIOSTATIC -Stops the growth of the bacteria BACTERICIDAL - Kills the bacteria Biotics lab

11. SPECTRUM : Range of activity of the compound Mycobacteria Gm Negative Gm Positive Anaerobes MRSA Isoniazid Tobramycin Penicillins, Beta-lactamase inhibitors Glycopepetides Oxazolidinones Carbapenems Clindamycin Glycylcycline Biotics lab

12. Antibiotic Resistance Definition: Ability of the bacteria to remain unaffected to the inhibitory or lethal ( cidal ) effects of antibiotics. Biotics lab

13. Sensitivity Infection Cured Antibacterial Biotics lab

14. Resistance Infection Infection Antibacterial Biotics lab

15. Mechanism of resistance Biotics lab

16. Beta lactams penicillins cephalosporins carbapenems monobactams 1 st gen 2 nd gen 3 rd gen 4 th gen 5 th gen Natural penicillins Penicillin G Penicillin V Benzathine P Procaine P Penicillinase R M e t hi c illin Nafcillin C lo x a c illin aminopenicillins Amoxycillin ampicillin Extended spectrum Ticarcilin Piperacilin carbenicillin Imipenem M eropenem Ertapenem a z treo n am Cefadroxil Cephalexin C ephradine cefazolin Cefaclor C e f a m andole Cefuroxime cefoxitin Cefotaxime C e f ta z idi m e ceftriaxone Cefpodoxime Cefixime Cefoperazone C e f epi m e Cefpirome Ceftaroline c e f tobi p r o le Biotics lab

17. Spectrum of activity: Penicillins Natural penicillins G+ve bacteria: streptococci,L. monocytogenes some anaerobes, some spirochaetes, G-ve: N.meningitidis,some H. Infl Penicilinase R S. aureus, S. Epidermidis Aminopenicillins Similar to natural penicillins with additional G-ve:E.coli, P. Mirabilis, S.enterica, Shigella spp. Aminopenicillin/ B lactamase Inhibitors Sulbactam and clavulanate inactivate the B lactamases and broaden aminopenicillin activity: Some S. Aureus, many enterobacteriaceae, clostridia except difficile, Bacteroides spp Extended spectrum p. aeruginosa Biotics lab

18. CEPHALOSPORINS Biotics lab

19. Most commonly used Antibiotics- Cephalosporins Beta-lactam antibiotics are among the most commonly prescribed drugs, grouped together based upon a shared structural feature, the beta- lactam ring. Cephalosporins cover a broad range of organisms, are generally well-tolerated, and are easy to administer; thus, these agents are frequently used beta-lactam drugs Biotics lab

20. Beta lactam ring Penicillins Cephalaosporins All beta lactam antibiotics have this beta lactam ring common Biotics lab

21. Cephalosporins Gram (+) & gram (-) Resistant to beta - lactamase Bactericidal - action similar to PCN’s 4 groups (generations) - each effective against a broader spectrum of bacteria about 10% of people allergic to PCN also to allergic to cephalosporins Action - inhibits bacterial cell wall synthesis IM & IV - onset = immediate 21 Biotics lab

22. Cephalosporins 1 st gen 1st Generation Cephalosporins - cefadroxil & cephalexin- PO; Cefazolin & cephalothin - IM More Gram (+), & less gram (-) Esp. used for skin/skin structure infections surgical prophylaxis Biotics lab

23. Cephalosporins-2 nd Gen 2nd Generation Cephalosporins - cefaclor - PO, cefoxitin, cefuroxime - IM & IV Gram (+), slightly boarder gram (-) effect than 1st generation for harder to treat infections Biotics lab

24. THERAPEUTIC USES Upper RTI (weaker effect) Pneumonia UTI Skin infections Bone infections Gonorrhea Surgical prophylaxis(cefuroxime 1.5 G 1hour prior ) Meningitis (cefuroxime ; but less effective than 3 rd generation ) Biotics lab

25. Cephalosporins-3 rd Gen 3rd Generation Cephalosporins - cefotaxime, ceftazidime , Cefpodoxime, ceftriaxone, cefixime, Cefoperazone - IM or IV More effective against gram (-), less effective against gram (+) for harder yet to treat infections Biotics lab

26. Cephalosporins-3rd Gen Has the best penetration into the CSF; almost no nephrotoxicity. Some of them are effective against P.aeruginosa and enteric bacilli. ( cefoperazone and ceftazidime) Biotics lab

27. Unique properties of 3rd generation Ceftriaxone has the longest half-life(8h) of any cephalosporin. Cefixime is an oral preparation. Ceftazidime is the best anti-pseudomonal cephalosporin. Cefoperazone is eliminated(70%) in the bile and is thus very useful in patients with renal failure. Biotics lab

28. THERAPEUTIC USES Used for serious infections caused by organisms resistant to other drugs. Gonorrhea : cefixime / ceftriaxone Meningitis : Ceftriaxone, cefotaxime community acquired pneumonia: ceftriaxone Septicemia Nosocomial infections UTI, LRTI Soft tissue infections, cellulitis Typhoid fever, Urethral, biliary tract infections Biotics lab

29. THERAPEUTIC USES Gonorrhea(single dose of ceftriaxone;1 st line drug) Meningitis ( good penetration in CSF) Sepsis Typhoid (4g ceftriaxone/day for 2 days,then 2g/day for 2 days) Surgical prophylaxis UTI Intra-abdominal infections Biotics lab

30. Cephalosporins-4 th Gen 4th Generation Cephalosporins - cefepime, cefpirome - IV or IM Resistant to most beta- lactamase bacteria greater gram (+) coverage than 3rd generation Biotics lab

31. Cephalosporins Each successive generation has broader activity against aerobic G- ves . Limited activity against anaerobes Lack activity against L. Monocytogenes and enterococci 1st gen : good cover for aerobic G+ve cocci(staph/strep), some G- ves . 2nd gen : increased activity against aerobic G- ve and facultative( E.coli,P.mirabilis,H.infl,B.fragilis 3rd gen : in addition, activity against B burgdorferi, greater activity against aerobic G-ve than 2nd gen , shortlived activity against enterobacteriaceae, no activity against p.aeroginosa except ceftazidime 4th and 5th gen : good antipseudomonal and antistaph cover, also enterobacteriaceae Biotics lab

32. C a r b ap e n e m s Biotics lab

33. Classification Biotics lab

34. Meropenem Slightly greater activity against Gram-negative aerobes Meropenen : penetrates CSF: only drug in this class used in the treatment of bacterial meningitis. More soluble than imipenems Dose: 1 gm/IV/ q 8 hrs. Excessive levels in kidney failure can cause seizures with imipenem but not with meropenem. Toxicity similar to GI disturbance/ Allergy/ CNS disturbances – Biotics lab

35. M e r op e ne m Newer drug Not sensitive to dipeptidase – cilastatin is not required Toxicity Similar to imipenem But less likely to cause seizures Biotics lab

36. Meropenem-Indications Infection Dose to Be Administered Every 8 Hours Pneumonia, including community-acquired pneumonia and nosocomial pneumonia 500 mg or 1 g Broncho-pulmonary infections in cystic fibrosis 2 g Complicated urinary tract infections 500 mg or 1 g Complicated intra-abdominal infections 500 mg or 1 g Intra- and post-partum infections 500 mg or 1 g Complicated skin and skin structure infections 500 mg or 1 g Acute bacterial meningitis 2 g Management of febrile neutropenic patients 1 g Biotics lab