Antibiotics Flashcards Preview

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Flashcards in Antibiotics Deck (22):
1

Oxacillin, nafcillin, dicloxacillin

Pencillinase-resistant penicillins

  • Bulky R group blocks access of beta-lactamase to beta-lactam ring
  • Toxicity: interstitial nephritis

2

Ticarcellin, piperacillin

Antipseudomonals

  • Susceptible to pencillinase (use with beta-lactamase inhibitors)

3

Clavulanic acid, Sulbactam, Tazobactam

Beta-lactamase inhibitors

  • "CAST"

4

Cefazolin, cephalexin

1st generation cephalosporins

Toxicity: vit K deficiency, increased nephrotoxicity of aminoglycosides

5

Cefoxitin, cefaclor, cefuroxime

2nd generation cephalosporins

Toxicity: vit K deficiency, increased nephrotoxicity of aminoglycosides

6

Ceftriaxone, cefotaxime, ceftazidime

3rd generation cephalosporins

  • Ceftriaxone treats meningitis, gonorrhea
  • Ceftazidime treats Pseudomonas

Toxicity: vit K deficiency, increased nephrotoxicity of aminoglycosides

7

Cefepime

4th generation cephalosporins

  • Anti-pseudomonal coverage

Toxicity: vit K deficiency, increased nephrotoxicity of aminoglycosides

8

Ceftaroline

5th generation cephalosporins

  • MRSA coverage; no psuedomonas coverage

Toxicity: vit K deficiency, increased nephrotoxicity of aminoglycosides

9

Aztreonam

Monobactam resistant to beta-lactamases

Only treats gram-negative rods

Synergistic with aminoglycosides

10

Imipenem, meropenem, ertapenem, doripenem

Carbapenems

  • Wide-spectrum (gram pos, gram neg, anaerobes), beta-lactamase-resistant
  • Imipenem always administered with cilastatin (inhibits renal hydropeptidase I) to decrease inactivation of drug in renal tubules
  • Meropenem has decreased risk of seizures and is stable to dehydropeptidase I
  • Toxicity: GI distress, skin rash, seizures

11

Vancomycin

Bactericidal. Binds D-ala D-ala portion of cell wall precursors.

Toxicity: Nephrotoxicity, Ototoxicity, Thrombophlebitis ("NOT" trouble free); Red Man Syndrome (prevented with slow infusion and antihistamines)

12

Protein synthesis inhibitors

"Buy AT 30CCEL at 50"

Aminoglycosides (bactericidal) and Tetracyclines target 30S

Chloramphenicol, Clindamycin, Erythromycin (macrolides), and Linezolid target 50S

13

Gentamicin, Neomycin, Amikacin, Tobramycin, Streptomycin

Aminoglycosides

  • Bactericidal inhibitors of 30S that inhibit formation of initiation complex, cause misreading of mRNA, and block translocation
  • Require O2 for uptake (ineffective vs. anaerobes)
  • Treats severe gram-negative rod infections
  • Toxicity: Nephrotoxicity (especially when used with cephalosporins), Neuromuscular blockade, Ototoxicity (especially when used with furosemide), Teratogen
  • Resistance: inactivation via acetylation, phosphorylation or adenylation

14

Tetracycline, doxycycline, minocycline

Tetracyclines

  • Bacteriostatic inhibitors of 30S that prevent attachment of aminoacyl-tRNA
  • Treats Borrelia burgdorferi, M pneumoniae, Rickettsia, Chlamydia, Acne; limited CNS penetration
  • Doxycyline can be used in renal failure (fecally eliminated)
  • Divalent cations inhibit absorption in gut
  • Toxicity: photosensitivity, teratogen
  • Resistance: decrease uptake or increase efflux via plasmid-encoded transport pumps

15

Azithromycin, clarithromycin, erythromycin

Macrolides

  • Bacteriostatic inhibitors of 23S rRNA subunit of 50S that block translocation ("macroslides")
  • Treats atypical pneumonias, chlamydia, and gram-positive cocci
  • Toxicity: GI motility issues, Prolonged QT, cholestatic hepatits, rash, eosinophilia, inhbit cytochrome p450
  • Resistance: methylation of 23S rRNA-binding site

16

Chloramphenicol

Bacteriostatic inhibitor of peptidyltransferase at 50S subunit

Treats meningitis (H flu, N meningitidis, S pneumonia) and Rickettsia rickettsii

Toxicity: anemia, aplastic anemia, gray baby syndrome (in premies due to lack liver UDP-glucuronyl transferase)

Resistance: plasmid-encoded acetyltransferase inactivates drug

17

Clindamycin

Bacteriostatic inhibitor of translocation at 50S subunit

Treats anaerobic infections above the diaphragm and GAS

Toxicity: C diff

18

Sulfamethoxasole, sulfisoxazole, sulfadiazine

Sulfonamides

  • Bacteriostatic inhibitor of dihydropteroate synthase (converts pteridine and para-aminobenzoic acid to dihydropteroic acid, a precursor of folate)
  • Toxicity: hemolysis in G6PD deficiency, tubulointerstitial nephritis, photosensitivity, kernicterus in infants, displaces warfarin from albumin

19

Trimethroprim

Bacteriostatic inhibitor of dihydrofolate reductase

Toxicity: megaloblastic anemia, leukopenia, granulocytopenia

20

Fluoroquinolones

Bactericidal inhibitors of DNA gyrase (topoisomerase II) and topoisomerase IV

Toxicity: tendonitis, tendon rupture, myalgias, teratogen

21

Metronidazole

Bactericidal, antiprotozoal activity. Forms free radicals in the bacterial cell wall that damage DNA

Treats Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, Anaerobes below the diaphragm

Toxicity: disulfiram-like reaction with alcohol; metallic taste

22

Linezolid

Bacteriostatic inhibitor of initiation complex formation by binding to the 23S portion fo the 50S subunit

Treats MRSA and VRE