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34 Cards in this Set
- Front
- Back
Standard penicillins
iv (1) po (1) im (1) Antibacterial spectrum? |
Penicillin G (i.v.)
Penicillin V (p.o.) Procaine penicillin G (i.m.) Benzathine penicillin G (i.m.) Antibacterial spectrum: Active against many G(+) and some G(-) G(+) cocci : e.g., Streptococcus, Staphylococcus, Enterococcus G(+) bacilli: e.g., Actinomyces, Bacillus G(-) cocci: e.g., Nisseria |
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Antistaphylococcal penicillins (resistant to staphylococcal β-lactamases) (5)
Antibacterial spectrum? |
Methicillin
Nafcillin Oxacillin Cloxacillin Dicloxacillin Antibacterial spectrum: Active against some -lactamase-expressing Staphylococci, but not active against G(-). * β-lactamases are a group of enzymes that inactivate many β-lactam antibiotics. |
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Extended-spectrum penicillins
(3) Antibacterial spectrum? |
Aminopenicillins
Ampicillin Amoxicillin * Antibacterial spectrum: Active against more G(-) than std penicillins. |
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Antipseudomonal penicillins
Carboxypenicillins (2) Ureldeopencillins (2) Antibacterial spectrum? |
(Carboxypenicillins)
Carbenicillin Ticarcillin (Ureidopenicillins) Piperacillin Mezlocillin * Antibacterial spectrum: Active against more G(-), including Pseudomonas, than std penicillins. |
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Cephalosporins
• 1st generation: (4) Antibacterial spectrum? |
Cephalexin
Cephalothin Cephradine Cefazolin * Antibacterial spectrum: Active against many G(+) cocci, not active against G(-). |
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Cephalosporins
• 2nd generation: (4) Antibacterial spectrum? |
Cefuroxime
Cefonicid Cefotetan Cefoxitn * Antibacterial spectrum: Extended activity against some G(-), but less active against G(+) than 1st generation. |
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Cephalosporins
• 3rd generation: (6) Antibacterial spectrum? |
Cefoperazole
Ceftriaxone Ceftazidime Cefotaxime Ceftizoxime Cefixime * Antibacterial spectrum: Exclusively active against G(-). |
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Cephalosporins
• 4th generation: (1) Antibacterial spectrum? |
Cefepime
* Antibacterial spectrum: Active against both G(+) and G(-). |
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Carbapenems: (3)
Antibacterial spectrum? Notable tox? |
Imipenem : used with Cilastin (an inhibitor of renal dehydropeptidase I)
Meropenem Ertapenem * Antibacterial spectrum: Active against many G(+), G(-), aerobes and anaerobes; more resistant to β-lactamases. * Renal dehydropeptidase I metabolizes imipenem to a renal-toxic metabolite with no antibacterial activity. |
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Monobactam: (1)
Antibacterial spectrum? |
Aztreonam
-Active against G(-). |
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Combination preparations of penicillins: (4)
purpose of combinations? |
Amoxicillin + clavulanic acid (Augmentin®)
Ampicillin + sulbactam (Unasyn®) Ticarcillin + clavulanic acid (Timentin®) Piperacillin + tazobactam (Zosyn®) * The use of B-lactamase inhibitors in these combination preparations extends the antibacterial spectrum of the penicillins. |
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Non-β-lactam antibiotics (other cell wall/membrane inhibitors)
(5) + what they are active against |
Vancomycin: Active against G(+) only.
Bactitracin: Active against G(+) only. Cycloserine: Active against both G(+) & G(-). Fosfomycin: Active against both G(+) & G(-). Daptomycin: Active against many vancomycin-resistant strains. |
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Bacterial cell wall
-description -two amino sugars |
Bacterial Cell Wall Synthesis
The β-lactam antibiotics act by interfering with the synthesis of the bacterial cell wall. The walls of bacteria are made of peptidoglycan, which contains both amino acids and amino sugars. The amino sugars are of two kinds * N-acetylglucosamine (NAG) * N-acetylmuramic acid (NAM) |
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Describe NAG & NAM
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NAG and NAM are linked by a glycosidic bond. Side chains containing 4 or 5 amino acids are attached to each NAM. These form covalent bonds with amino acids in adjacent chains. The bonds may be direct to the next chain or include additional peptide cross bridges (e.g., 5 glycine residues) which extend to chains in the same plane as well as to chains above and below.
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Describe peptiodoglycan synthesis
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Peptidoglycan synthesis is catalyzed by several enzymes. Transglycosidase enzymes join peptidoglycan monomers together to form chains. Transpeptidase (aka penicillin-binding protein or PBPs) then mediates the removal of last D-Ala from the precursor of peptidoglycan and cross-links the chains.
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•Mechanism of action of β-lactam antibiotics:
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The β-lactam antibiotics act by interfering with the synthesis of the bacterial cell wall. Due to their structural similarity to the D-Ala-Ala residue, the β-lactam antibiotics bind to and inhibit transpeptidase (aka Penicillin-binding protein) needed for the synthesis of the peptidoglycan.
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•Mechanism of action of vancomycin:
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A glycopeptides; inhibits cell wall synthesis by binding to the D-Ala-D-Ala residue, which prevents the incorporation of NAM/NAG peptide subunit into the peptidoglycan (i.e., inhibiting the transglycosidase reaction).
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•Mechanism of action of bacitracin:
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Interferes with dephosphorylation at the late stage of bacterial cell wall synthesis.
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•Mechanism of action of cycloserin:
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Structure analog of D-Ala; inhibits alanine racemase, thereby inhibiting the incorporation of D-Ala into peptidoglycan.
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•Mechanism of action of fosfomycin
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Structure analog of phosphoenolpyruvate; inhibits enolpyruvate transferase activity, thereby interfering with early stage of bacterial cell wall synthesis.
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•Mechanism of action of daptomycin:
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Binds and depolarize cell membrane, causing potassium influx and cell death.
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Antibiotics- Protein Synthesis Inhibitors
Inhibitors of 30S ribosomal subunits (2) |
o Tetracyclines
o Aminoglycosides |
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Inhibitors of 50S ribosomal subunits
(6) |
o Macrolides
o Ketolides o Streptogramins o Oxazolidones o Clindamycin o Chloramphenicol * Most protein synthesis inhibitors are bacteriostatic agents, except for aminoglycosides and streptogramins which are generally bactericidal agents |
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Tetracyclines (7)
MOA Antibacterial spectrum |
Tetracycline
Doxycycline Minocycline Oxytetracycline Demeclocycline Methacycline Tigecycline (reversible binding to bacterial 30S ribosomal subunits) * Antibacterial spectrum: Active against G(+), G(-) & anaerobes (broad spectrum) |
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•Aminoglycosides (7)
MOA Antibacterial spectrum |
Gentamycin
Streptomycin Amikacin Neomycin Kanamycin Tobramycin Paromomycin (irreversible binding to bacterial 30S ribosomal subunits) * Antibacterial spectrum: Active against aerobic G(-) rods and some G(+) |
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•Macrolides (3)
Antibacterial spectrum |
Erythromycin
Clarithromycin Azithromycin Antibacterial spectrum: Active against many G(+) and some G(-), as well as mycoplasma pneumoniae |
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•Ketolides (1)
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Thelithromycin
(similar to macrolides but active against some macrolide-resistant strains) |
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•Streptogramins (1)
Antibacterial spectrum |
Quinuprstin-dalopristin
* Antibacterial spectrum: Active against G(+) |
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•Oxazolidones
Antibacterial spectrum |
Linezolid
* Antibacterial spectrum: Active against G(+) |
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Clindamycin :
Chloramphenicol: |
Clindamycin : Active against G(+)
Chloramphenicol : Broad spectrum; active against many G(+) &G(-) |
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DNA synthesis inhibitors
Anti-folate antibiotics • Sulfonamides • Pyrimidines Fluoroquinolones RNA synthesis inhibitors (1)Rifampin (inhibit DNA-dependent RNA polymerase) |
Rifampin (inhibit DNA-dependent RNA polymerase)
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•Sulfonamides
MOA Antibacterial spectrum: |
ulfonamides (structurally similar to PABA; inhibits DHPS during folate synthesis)
Sulfisoxazole Syulfamethizole Sulcytine Sulfadiazine Sulfamethoxazole (SMZ) Sulfapyridine Sulfadoxine Sulfasalazine * Antibacterial spectrum: bacteriostatic; active against G(+), G(-) & Clamydia |
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•Pyrimidines
MOA Antibacterial spectrum: |
(inhibit bacterial DHFR during folate synthesis)
Trimethoprim (TMP) Pyrimethamine (inhibits protozoal DHFR) * Both sulfonamides and pyrimidines are anti-folate agents; pyrimidines can be used in combination with sulfonamides to achieve a synergistic (bactericidal) effect (e.g., TMP-SMZ) |
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•Fluoroquinolones (8)
MOA Antibacterial spectrum: |
(inhibit DNA gyrase/ topoisomerase II & topoisomerase VI)
Norfloxacin Ciprofloxacin Levofloxacin Ofloxacin Enoxacin Lomefloxacin Moxifloxacin Gemifloxacin Antibacterial spectrum: bactericidal/bacteriostatic; against various G(+) & G(-) |