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Flashcards in Pharm: Antibiotics Deck (26):
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Penicillin

Mechanism: binding of PBPs blocks peptidoglycan cross-linking
Use: gram+ cocci, gram- cocci, N meningitidis, T pallidum
SE: allergic rxn, hemolytic anemia

1

Aminopenicillins (ampicillin, amoxicillin)

Mechanism: binding of PBPs blocks peptidoglycan cross-linking
Use: penicillin coverage + gram- rods (HELPSS: H flu, E coli, Listeria, Proteus, Salmonella, Shigella)
SE: allergic rxn, rash, pseudomembranous colitis (C diff)

2

Methicillin, naficillin, oxacillin, dicloxacillin

Mechanism: binding of PBPs blocks peptidoglycan cross-linking; β-lactamase resistant
Use: S aureus (except MRSA)
SE: interstitial nephritis (methicillin)

3

Piperacillin, ticarcillim, carbenicillin

Mechanism: binding of PBPs blocks peptidoglycan cross-linking
Use: Pseudomonas, gram- rods
SE: allergic rxn

4

Clavulanic acid, sulbactam, tazobactam

β lactamase inhibitors

5

Aztreonam

Mechanism: binding of PBPs blocks peptidoglycan cross-linking
Use: gram- rods; used in pts with penicillin allergy or renal insufficiency
SE: GI upset

6

Carbapenems (imipenem, meropenem)

Mechanism: binding of PBPs blocks peptidoglycan cross-linking
Use: wide spectrum, used with serious infxn; must administer with cilastatin (renal dihydropeptidase I inhibitor)
SE: seizures, GI upset, rash

7

1st gen cephalosporins (cefazolin, cephalexin)

Mechanism: binding of PBPs blocks peptidoglycan cross-linking; more β-lactamase resistant
Use: UTIs from Proteus, E coli, Klebsiella (PEK) + gram+ cocci
SE: allergic rxn, disulfiram-like rxn, nephrotoxicity

8

2nd gen cephalosporins (cefoxitin, cefaclor, cefuroxime)

Mechanism: binding of PBPs blocks peptidoglycan cross-linking; more β-lactamase resistant
Use: H flu, Enterobacter, Neisseria, Proteus, E coli, Klebsiella, Serratia (HEN PEKS) + gram+ cocci
SE: allergic rxn, disulfiram-like rxn, nephrotoxicity

9

3rd gen cephalosporins (ceftriaxone, cefdinir, cefotaxime, ceftazidime)

Mechanism: binding of PBPs blocks peptidoglycan cross-linking; more β-lactamase resistant
Use: serious gram- infections (including pseudomonas)
SE: allergic rxn, disulfiram-like rxn, nephrotoxicity

10

4th gen cephalosporins (cefepime)

Mechanism: binding of PBPs blocks peptidoglycan cross-linking; more β-lactamase resistant
Use: gram- + increased activity against pseudomonas, gram+
SE: allergic rxn, disulfiram-like rxn, nephrotoxicity

11

5th gen cephalosporins (ceftaroline)

Mechanism: binding of PBPs blocks peptidoglycan cross-linking; more β-lactamase resistant
Use: broad spectrum coverage + MRSA (doesn't cover pseudomonas)
SE: allergic rxn, disulfiram-like rxn, nephrotoxicity

12

Aminoglycosides (gentamicin, neomycin, amikacin, tobramycin, streptomycin - GNATS)

Mechanism: bind 30s subunit > inhibit formation of initiation complex and cause mRNA misreading
Use: severe gram- rod infections; synergistic with β-lactam antibiotics
SE: nephrotoxicity, ototoxicity, teratogenic

13

Clindamycin

Mechanism: bind 50s subunit, block peptide transfer (translocation)
Use: anaerobic infections above the diaphragm, invasive GAS infxn
SE: pseudomembranous colitis (C diff), fever, diarrhea

14

Chloramphenicol

Mechanism: binds to 50s subunit, blocks peptidyltransferase
Use: meningitis and Rocky Mountain spotted fever
SE: anemia (dose-dependent), aplastic anemia (dose-independent), gray baby syndrome

15

Macrolides (erythromycin, azithromycin, clarithromycin)

Mechanism: binds 50s subunit, inhibits formation of initiation complex and translocation
Use: atypical Pneumonia, URIs (GAS), STDs (Chlamydia) (PUS); MAC prophylaxis in AIDS pts
SE: GI upset, long QT arrhythmia, acute cholestatic hepatitis, rash, eosinophilia; P-450 inhibitor

16

Tetracyclines (tetracycline, doxycycline, minocycline)

Mechanism: binds 30s subunit, blocks aminoacyl-tRNA from binding
Use: Vibrio, acne, Chlamydia, Ureaplasma, M pneumoniae, Tularemia, H pylori, B burgdorferi, R riskettsii (VACUM TH BR)
SE: GI upset, teeth discoloration and bone deformity in children, photosensitivity

17

Trimethoprim-Sulfamethoxazole (TMP-SMX/Bactram)

Mechanism: TMP inhibits dihydrofolate reductase; SMX is a PABA analogue that inhibits dihydropteroate synthase
Use: UTIs, Shigella, Salmonella, and Pneumocystis treatment and prophylaxis, toxoplasmosis prophylaxis in AIDS pts
SE: SJS, hemolytic anemia, granulocytopenia, kernicterus in newborns

18

Fluoroquinolones (ciprofloxacin, norfloxacin, ofloxacin, levofloxacin)

Mechanism: inhibit DNA topoisomerase II, causing DNA strand breakage
Use: gram- UTIs and GI infxns, Neisseria gonorrhea
SE: tendonitis, tendon rupture, damage growing cartilage, GI upset, rash, headache, dizziness

19

Vancomycin

Mechanism: binds D-ala D-ala terminus of cell wall precursors
Use: gram+ only, reserved for drug-resistant infxns (MRSA, C diff)
SE: nephrotoxicity, ototoxicity, thrombophlebitis, red man syndrome

20

Metronidazole

Mechanism: forms free radical toxic metabolites to damage DNA
Use: Giardia, Entamoeba, Trichomonas, Gardnerella, Anaerobes, H Pylori (GET GAP)
SE: disulfiram-like rxn, headache, metallic taste

21

Rifampin

Mechanism: inhibits bacterial DNA-dependent RNA polymerase
Use: tuberculosis, leprosy, prophylaxis for meningococcal meningitis and H flu type B
SE: red-orange secretions, hepatotoxicity, induces P-450

22

Isoniazid

Mechanism: decreases synthesis of mycolic acids
Use: tuberculosis treatment and prophylaxis
SE: hepatotoxicity, give pyridoxine (B6) to prevent neurotoxicity, drug-induced lupus

23

Pyrazinamide

Mechanism: uncertain; requires activation in acidic pH (phagolysosomes)
Use: tuberculosis
SE: hepatotoxicity, hyperuricemia

25

Ethambutol

Mechanism: inhibits arabinosyl transferase, blocks synthesis of mycobacterial cell wall
Use: tuberculosis
SE: retrobulbar neuritis > red-green color blindness

26

What three categories of PBP-binding drugs are resistant to the activity of beta-lactamase?

Cephalosporins, carbapenems, and methicillin/nafcillin