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58 Cards in this Set
- Front
- Back
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Excretion of Penicillins via glomerular filtration and tubular secretion is inhibited by what drug?
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Prebenecid
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Penecillin that is excreted in the Bile
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Nafcillin
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IM Penicillin G drugs that have the longest half lives, due to their slow release into the blood stream
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Procaine and Benzathine
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B Lactams are what type of antibiotic?
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bactericidal
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Mechanism of action of Beta Lactams:
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inhibit cell wall synthesis by: binding to PBP's, inhibiting the cross linking of the linear peptidoglycan chain, and activation of autolytic enzymes, that form lesions in the cell wall
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Major mechanism of resistance by Staphylococci and other gram negative bacteria
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Formation of Beta Lactamases (penicillinases)
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Inhibitors of B Lactamases used in combination with b lactams to prevent their inactivation
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Clavulanic acid, tazobactam, and Sulbactam
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Structural change in target PBPs is a major source of resistance in what two bacteria, and for what drugs?
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Staphylococcus for methicillin, and Streptococcus Pneumoniae for penicillin G, and enterococci
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Gram negative rod that changes its outer cell wall membrane porin structure, as a mechanism of resistance
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Pseudomonas Aeruginosa, blocks access of penicillins to PBP's
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Narrow spectrum penicillinase susceptible agents used for treatment of Strep, Meningococci, Gram + Bacilli, and spirochetes
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Penicillin G
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Bacteria resistant to Penicillin G
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Staph Aureus, Strep Pneumoniae, and Neisseria Ghonorrhea.
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Penicillin is still the drug of choice for which STD?
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Syphilis
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Combination with aminoglycosides increases Penicillin G's effectiveness against which organisms?
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enterococci
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Very narrow spectrum penicillinase resistant drugs, and the primary bacteria they target
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Methicillin, Nafcillin, Dicloxacillin (oxacillin) and Carbenicillin. Used to treat Staph infections
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Two bacteria that are resistant to all penicillins and most other antimicrobial drugs as well
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Staph aureus (MRSA) and Staph Epidermidis (MRSE)
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Wider spectrum penicillinase susceptible drugs used to treat Lysteria, E-Coli, Proteus, and Haemophilus Influenza. Main treatment for Otitis Media
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Amoxicillin and Ampicillin. greater effectiveness against B lactamases when used with clavulanic acid, tazobactam, etc...
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Penicillins with activity against Gram - rods (Pseudomonas, Klebsiella, and Enterobacter)
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Piperacillin and Ticarcillin, greater effectiveness against B lactamases when used with clavulanic acid, tazobactam, etc...
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Toxicities of Penicillins:
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Allergy: urticartia, pruritis, fever, joint swelling etc...
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Penicillin that causes interstitial nephritis
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Methicillin
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Penicillin that causes neutropenia
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Nafcillin
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Penicillin that causes a maculopapular rash, not considered an allergic reaction, and has been implicated in pseudomembranous Colitis
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Ampicillin
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Side effect of all penicillins
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GI upset (nausea and diarhhea) ampicillin is the worst
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Cephalosporins Mechanism of action, and cross sensitivity
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same as that of penicillin, and have a 10-15% cross sensitivity with penicillins
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two cephalosporins secreted in the bile, and not the kidney
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cefoperazone and ceftriaxone (3rd generation)
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Advatnage of cephalosporins over penicillins
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they are les susceptible to Staph B lactamases
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Drug that is resistant to both penicillins and cephalosporins
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MRSA
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1st generation cephalosporins and their target organisms
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Cefazolin (parenternal) and Cephalexin (oral) active against gram + cocci (common staph, strep, ecoli, and K pneumonia) also used for surgical prohpylaxis
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2nd generation cephalosporins and their target organisms
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(Have less gram +, more gram - coverage) cefotetan and cefoxitin are used for Bacteroides fragillis, and cefamandole, cefuroxime, and cefaclor are used for sinus, ear, and resp infections caused by H influenzae or M catarrhalis
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3rd generation Cephalosporins that cross the BBB
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Ceftazidime, cefotaxime, ceftriaxone, ceftizoxime
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3rd generations that dont cross BBB
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cefoperazone and cefixime
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Organisms that most 3rd gen cephalosporins are active against
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Providencia, Serratia Marcescens, and B lactamase producing strains of H influenza and Neisseria.
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3rd Gens that are most active against PRSP strains (although some resistance is reported)
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Ceftriaxone and Cefotaxime
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3rd gen with activity against pseudomonas
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cefoperazone, ceftazidime
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3rd gen with activity against B Fragilis
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ceftizoxime
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Drugs of choice for Ghonorrhea
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ceftriaxone (parenternal) or cefixime (oral)
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For otitis media, a single injection of this drug is as effective as a 10 day course of amoxicillin
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ceftriaxone
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4th Generation Cephalosporin that combines the gram + activity of the 1st gens with the gram - activity of the 3rd gens
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Cefepime. used to treat: Enterobacter, haemophilus, Neisseria, and some PRSP's.
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Toxicities
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Allergy: from skin rashed to anaphylactic shock, 5-10% cross sensitivity with penicillins
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Which two cephalosporins may cause hypoprothrombinemia and disulfiram reactions when used with ethanol
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cefamandole, cefoperazone, cefotetan
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Beta Lactamase resistant Monobactam with no activity against gram + or anaerobes
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Aztreonam (IV administered) works on gram - rods like Klebsiella Pseudomonas, and Serratia
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Aztreonam Toxicities: (no cross allerginicity with penicillin)
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causes GI upset with possible superinfection, Half life increased in renal failure, vertigo, headache, and hepatotoxicity.
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What are Carbapenems, and what are they used for?
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Miropenem, Ertapenem, Imipenem. (parenternal drugs) have wide activity against: gram + cocci, gram - rods, and anaerobes
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What drugs are they combined with for increased activity?
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aminoglycosides
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Bacteria that are resistant
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MRSA
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Carbapenem that is rapidly broken down by renal dihydropeptidase 1, causing seizures, unless administered with cilastatin
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Imipenem. could also just give miropenem instead
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Beta Lactamase inhibitors
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Clavulanic acid, tazobactam, and Sulbactam
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MOA of vancomycin
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Binds to D-ala-d-ala terminal, blocking elongation of peptidoglycan chain, and interfering with cross linking
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Resistance to vancomycin
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point mutation of lactate for alanine, causing a decreased affinity for vancomycin for that site
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2 drugs resistant to vancomycin
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vancomycin resistant enterococci (VRE) and vancomycin resistant Staph Aureus) VRSA
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Use of Vancomycin
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only for serious infections caused by organisms resistant to other drugs. can be used for MRSA, MRSE, PRSP, resistant clostridium difficile,
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Glycopeptide, similar to vancomycin, used for similar purposes
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Teicoplanin
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Toxic effects of Vancomycin
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chills, fever phlebitis, ototoxicity, and nephrotoxicity. must alter dose in renal impairment
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Syndrome caused by Vancomycin
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Red man syndrome, is an allergic reaction caused by too quick infusion. to treat, slow infusion, and give anti histamines
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Mechanism of action of Fosfomycin
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Antimetabolite inhibitor of cytosilic enulpyruvate, prevents formation of N-acetylmuramic acid, a precurser for peptidoglycan chain formation
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Use of Fosfomycin
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Is excreted unchanged in urine in very high levels, high enough to exceed the MIC for many urinary tract pathogens
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Topical Bacitracin
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used for gram + surface organisms, peptide antibiotic that interferes with a late stage in cell wall synthesis
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Cycloserine
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Used to treat TB that is resistant to first line druge
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Daptomycin
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cyclic lipopeptide, active against vancomycin strains of enterococci and Staphylococci.
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