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Flashcards in Antibiotics Deck (53):
1

Mechanism of Penicillin ABx

Bind Penicillin binding proteins (transpeptidases)
Block transpeptidase cross linking of peptidoglycan cell wall
Activate autolytic enzymes

2

Clinical use of Penicillin G (IV) and V (oral)

Gram positives
Syphilis (spirochetes)

3

S/E of Penicillin G and V

Hypersensitivity

4

Mechanism of resistance to Penicillin G/V

Penicillinase in bacteria (B lactamase that cleaves B lactam ring)

5

Which penicillin ABx is used for the following?
a. Syphilis
b. UTI
c. Pseudomonas
d. Neonatal infection

a. Penicillin G
b. Amoxicillin
c. Ticarcillin, Piperacillin
d. Ampicillin (plus Gentamicin)

6

Patient with mononucleosis is given a drug and develops full body rash. What were they given?

Amoxicillin

7

Which has greater oral bioavailability; Amoxicillin or Ampicillin?

Amoxicillin has greater oral bioavailability

8

Penicillinase-resistant Penicillins

Nafcillin, Oxacillin, Dicloxacillin

9

Clinical use for Penicillinase-resistant Penicillins

Staph aureus

10

Anti-pseudomonal Penicillins

Piperacillin, Ticarcillin

11

Beta lactamase inhibitors

Clavulonic acid
Tazobactam
Sulbactam

12

Organisms NOT covered by Cephalosporins (LAME)

Listeria
Atypicals (Chlamydia, Mycoplasma)
MRSA
Enterococci

13

Clinical use of:
a. 1st generation Cephalosporins
b. 2nd gen Cephalosporins
c. 3rd gen Cephalosporins
d. 4th gen Cephalosporins

a. Gram positives, Proteus, E. coli, Klebsiella (UTI, URI, Prophylaxis for Viridans strep endocarditis, prior to surgery)
b. Gram positives, PEcK plus H. influenzae, Enterobacter, Neisseria, Serratia
c. Serious gram negative infections; Ceftriaxone - meningitis, gonorrhea, Lyme disease; Ceftazidime - Pseudomonas
d. Cefepime - Pseudmonas, broad coverage

14

S/E of Cephalosporins

Disulfiram like reaction
Vit K deficiency
Cross reactivity with Penicillins = Hypersensitivity
Increased nephrotoxicity with Aminoglycosides

15

ABx to avoid in pregnancy

Tetracyclines - discolored teeth and inhibits bone growth
Fluoroquinolones - cartilage rupture
Aminoglycosides - nephro/oto toxicity
Clarithromycin - Embryotoxic
Sulfonamides - Kernicterus
Metronidazole - Mutagenesis
Ribavirin - Teratogenic
Griseofulvin - Teratogenic

16

Why is Imipenem administered with Cilastatin?

Cilastatin inhibits renal dehydropeptidase I to decrease the inactivation of Imipenem in renal tubules

17

Use of Carbapenems

WIDE spectrum
Does NOT cover MRSA

18

S/E of Carbapenems

Significant side effects
Seizures and CNS toxicity at high levels

19

Use of Aztreonam

Gram negative rods ONLY; for Penicillin allergic patients and those with renal insufficiency who cannot tolerate aminoglycosides

20

Mechanism of Vancomycin

Binds D-ala-D-ala portion of cell wall precursors and inhibits cell wall peptidoglycan formation

21

Use of Vancomycin

MRSA, C. difficile (oral)

22

S/E of Vancomycin

Nephrotoxic, Ototoxic, Thrombophlebitis, Red man syndrome

23

Cause of Red Man Syndrome

When taking Vancomycin there is nonspecific mast cell degranulation causing widespread release of histamine and diffuse flushing

24

Protein synthesis inhibitor Abx

Buy AT 30, CCEL at 50
Aminoglycosides
Tetracycline

Chloramphenicol
Clindamycin
Erythromycin - Macrolides
Linezolid

25

Mechanism of Aminoglycosides

Binds 30s subunit and causes misreading of RNA
REQUIRES 02 FOR UPTAKE

26

Use of Aminoglycosides

Gram negative rods (Neonatal infections)
Neomycin for bowel surgery

27

Why are Aminoglycosides not effective against anaerobes?

They require O2 for uptake

28

S/E of Aminoglycosides

Nephrotoxicity (worse with Cephalosporins), Ototoxicity, Teratogen

29

Mechanism of Tetracyclines

Binds 30s subunit and prevents attachment of amino-acyl tRNA

30

What should you avoid while taking Tetracyclines?

Milk (Calcium) , Antacids (Calcium or Mg), Iron - they disrupt absorption of the drug

31

Clinical use of Tetracyclines (VACUUM The BedRoom)

Vibro cholera
Acne
Chlamydia
Ureaplasma
Tularemia
Mycobacterium pneumoniae
Borrelia
Rickettsia

32

Why are Tetracyclines effective against Rickettsie and Chlamydia?

They can accumulate intracellularly.

33

S/E of Tetracycline

Discoloration of teeth
Inhibition of bone growth
Photosensitivity

34

S/E of Chloramphenicol (and cause of this)

Gray baby syndrome - they lack UDP glucuronyl transferase

35

S/E of Clindamycin

Pseudomembranous colitis

36

Use of Linezolids

MRSA
VRE

37

Mechanism of Macrolides

Erythromycin, Clarithromycin, Azithromycin - they bind 23sRNA of 50s subunit and block translocation

38

Use of Macrolides

Atypical pneumonias (Mycoplasma, Legionella, Chlamydia)
STIs (Chlamydia)
URIs
B. pertussis

39

Toxicity of Macrolides

Motility issues, Arrhythmia caused by long QT, acute Cholestatic hepatitis, Rash, Eosinophilia
Increases serum concentration of theophylline and anticoagulants
Clarithryomycin and Erythromycin inhibits p450 enzymes

40

Mechanism of Trimethoprim

Inhibits dihydrofolate reductase

41

Use of Trimethoprim

Used in combo with Sulfonamides for UTIs, Shigella, Salmonella, PCP prophylaxis and treatment, Toxoplasmosis prophylaxis

42

Sulfonamides mechanism

Inhibits folate synthesis (PABA antimetabolites inhibit dihydropteroate synthase)

43

Sulfa drugs (Sulfa Pills Frequently Cause Terrible Acute Symptoms)

Sulfasalazine
Probenecid
Furosemide
Celecoxib
Thiazides/TMP-SMX
Acetazolamide
Sulfonylureas

44

Mechanism of Nitrofurantoin

Reduced by bacterial proteins to a reactive intermediate that inactivates bacterial ribosomes

45

Use for Nitrofurantoin

UTI cystitis by E. coli or Staph saprophyticus
Safe in pregnancy

46

Mechanism of Fluoroquinolones

Inhibits prokaryotic enzymes topoisomerase II (DNA gyrase) and IV

47

What can you not take while taking Fluoroquinolones?

Antacids - inhibits absorption

48

S/E of Daptomycin

Myopathy, Rhabdomyolysis

49

Why is Daptomycin NOT used for pneumonia?

It avidly binds and is inactivated by Surfactant

50

Mechanism of Daptomycin

Disrupts cell membrane

51

Mechanism of Metronidazole

Forms toxic free radical metabolites in bacterial cell that damage DNA - ANTIprotozoal

52

Use of Metronidazole

Giardia
Entamoeba
Trichomonas
Gardnerella vaginalis
Anaerobes
H. pylori

53

S/E of Metronidazole

Disulfiram like reaction (flushing, tachycardia, hypotension) with alcohol