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30 Cards in this Set
- Front
- Back
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* ANTIMETABOLITES * (4)
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*ANTIMETABOLITES are those that interfere with the synthesis or function of a substance involved in normal cell function- - and it's usually similar to natural substance. We study the following:
1) SULFONAMIDE 2) TRIMETHOPRIM 3) BACTRIM 4) ISONIAZID |
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1) SULFONAMIDE
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C/S: static
TARGET: act against a wide range of bacteria including PROTOZOA - some are concentrated in the urine, so may use in UTIs MECHANISM: - penetrates sensitive bacteria to inhibit FOLIC ACID production by inhibiting one of the enzymatic steps - there is NO DNA SYNTHESIS - it is REVERSIBLE, so that when you stop using the drug, the growth of teh bacteria resumes |
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2) TRIMETHOPRIM
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C/S: static
TARGET: MECHANISM: - it acts of DIHYDROFOLATE REDUCTASE to inhibit its activity so that you can't get THF - you may use this with SULFONAMIDE and together they have SYNERGISTIC action and are sometimes used in conjunction to treat UTIs |
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3) BACTRIM
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C/S: static
TARGET: UTIs MECHANISM: combination of trimethoprim and bactrim is common |
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4) ISONIAZID
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C/S: cidal!!
TARGET: TB! MECHANISM: - takes specific action against TB (has a narrow spectrum) - it interferes iwth mycolic acid which is unique to the cell wall of mycobacteria - it inhibits the action of anyme InhA, which is essential for fatty acid elongation - it's good drug because it may penetrate through the human cytoplasmic membrane, impor because many mycobacteria are intracellular |
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* PENICILLIN *
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* penecillin causes bacteria to lyse, and it can prevent slow or lethal action to bacteria in medium
* all cell wall synthesis inhibitors are BACTERICIDAL as they INHIBIT THE STEPS OF PEPTIDOGLYCAN SYNTHESIS 1) PENICILLIN G 2) PENICILLIN V 3) AMPICILLIN 4) AMOXICILLIN 5) TICARCILLIN 6) PIPERACILLIN 7) METHACILLIN 8) OXACILLIN |
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1) PENECILLIN G*
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TYPE:
- SENSITIVE to penicillinase - also SENSITIVE to acid hydrolysis - LIMITED spectrum TARGET: - gram +ve and -ve cocci (like neisseria meningitis and treponema pallidum) - INEFFECTIVE against gram -ve enterics |
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2) PENECILLIN V*
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same as PENICILLIN G except it is ACID STABLE!
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3) AMPICILLIN**
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TYPE:
- SENSITIVE to penicillinase - BROADER spectrum TARGET: - active against gram -ve enterics - retains most activity against gram +ve bacteria *ACID STABLE! an aminopenicillin |
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4) AMOXICILLIN**
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*just like AMPICILLIN but has higher serum levels
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5) TICARCILLIN***
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TYPE:
- SENSITIVE to penicillinase - EXTENDED spectrum TARGET: - active against gram -ve bacteria such as p. aeruginose - LESS ACTIVE against cocci *B- lactam effective against p. aeruginosa, carboxypenicillin |
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6) PIPERACILLIN***
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*just like TICARCILLIN
- most active against gram -ve eneteric bacilli including p. aeruginosa and anaerobes |
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7) METHACILLIN*
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TYPE:
- acid labile - avoid usage in adults because it causes an increase in intestinal nephritis TARGET: - has slightly lower activity against gram +ve bacteria, but still effective - little against gram -ve |
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8) OXACILLIN*
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*just same as methacillin, newer more potent derivative
- acid labile and availble only orally |
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* CEPHALOSPORINS * (4)
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*They are similar to penicillins in mechanism of action, in that they target the cell wall with a 4- membered lactam ring, BUT substitute a dihidrothiazine ring instead of thiazolidine of the penicillins
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Important points about CEPHALOSPORINS? (5)
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1) bactericidal
2) differ from penicillins in that they have greater acid stability and are resistent to penicillinases 3) BROAD SPECTRUM antibiotics against both gram +ve and -ve bacilli 4) useful when patients are allergic to penicillin because they are antigenically dissimilar 5) as new members of the class of cephalosporins were developed, they were called 1st, 2nd, and 3rd generations- - differing in the spectrum of bacteria they could be used to treat against *the newer agents are active against pseudomonas, and can better penetrate the cerebral spinal fluid |
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1) CEFAZOLIN
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TYPE: FIRST GENERATIONS
TARGET: - this is most active aginst gram +ve cocci - it is active against most gram -ve eneterics BUT NOT PSEUDOMONAS |
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2) CEFUROXINE
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TYPE: 2ND GENERATION
TARGET: - improved pharmacologic spectrum - most effective against gram (-) ve bacteria - less effecitve against gram +ve - NOT EFFECTIVE AGAINST PSEUDOMONAS |
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3) CEFTRIAXONE
4) CEFTAZIDIME |
TYPE: THIRD GENERATION
TARGET: - improved B- lactamase stability - BROADER gram -ve spectrum - it is effective against pseudomonas - SUPERIOR CNS penetration |
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* OTHER B- LACTAM RINGS * (2)
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1) AZTREONAM (MONOBACTAMS)
2) IMIPENEM (CARBAPENEM) |
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1) AZTREONAM
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TYPE:
- resistant to B- lactamases and - minimal cross immunogenicity with other B- lactams TARGET: - effective against gram -ve bacteria and p. aeruginosa - INEFFECTIVE against gram +ve anaerobic bacteria |
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2) IMIPENEM
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TYPE:
- BROADEST ANTIMICROBIAL SPECTRUM - resistant to most lactamases - BUT it is susceptible to MRSA - acid is susceptible to dipeptidase |
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*B- LACTAMASE INHIBITORS * (2)
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1) CLAVULONIC ACID
2) SULBACTAM |
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1) CLAVULONIC ACID
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currently available in fixed combination with amoxicillin (augmentin)
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2) SULBACTAM
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available in fixed combo with ampicillin
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* GLYCOPEPTIDES * (2)
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1) VANCOMYCIN
2) TEICOPLANIN |
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1) VANCOMYCIN
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TYPE:
- only gram -ve MRSE, VSE TARGET: - activity restricted to gram +ve complex glycopeptides - binds to R-D-ALA-D-ALA block - somewhat toxic, BUT when less toxic drugs are ineffective or contraindicated, used against serious systemic staph/ enterococcal infections or orally for C. difficile enterocolitis - SIDE EFFECTS: hearing and kidney damage - available for MRSA AND MRE - VRE transfer resistance to MRSA and increase in VRE is an increasing problem |
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2) TEICOPLANIN
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TYPE:
- increase in LIPOPHILICITY - can penetrate the tissue well - less toxic TARGET: - chemically similar to vancomycin - greter lipophilicity over vancomycin and has a long elimnation 1/2 life - less toxic than vancomycin - DISADVANTAGE: no oral form - NOT APPROVED BY FDA |
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*CYCLOSERINE*
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TYPE:
secondary TB drug, TOXIC!! TARGET: - it's a D- ALA analog which inhibits L- ALA- - thus inhibiting cell wall synthesis |
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*BACITRACIN*
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TYPE:
TARGET: - restricted to gram +ve organisms - it inactivates the phosphatase responsible for regenerating the active form of the carrier lipid in murein precursor synthesis - TOXIC and restricted to TOPICAL therapy, often in conjunction with POLYMYXIN B and NEOMYCIN (like neosporin) |
