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Flashcards in intro to Abx,Cell wall/membrane attackers Deck (74)
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1

bactericidal

DNA replication (fluroQ + metronizadole)
RNA replication (rifampin)
cell wall attackers (except beta lactamase)
cell membrane (polymixins, daptomycin)
proteins: ONLY macrolides, streptoGs,aminoGs

2

batcteriostatic

"ECSTaTiCO about bacteriostatic" to be alive :)
Erythromycin
Clindamycin
Sulfonamides
Trimethoprim
Tetracyclines
Oxazolianones (linezolid)

3

combination therapy:syngery

increase killing power:
Utilize this when organism is unknown or special indications such as infectious endocarditis or tuberculosis

Concerns for combination therapy include:
Development of resistance
One drug interfering with the action of another
Tetracycline (bacteriostatic) interfering with penicillins (bactericidal)

ex/ PCN (cell wall) and aminoglycoside (protein synthesis): can get into cell wall to target ribosome.

4

combination therapy: antagonism

dont combine bactericidal and bacteriostatic- can use 2 Cidals or 2 Statics (slow growth inhibits cidal)

5

PCN: MOA, Adverse effects

MOA: crosslinking of cell wall (peptidoglycan)
Adverse: NEPHRITIS, hematologic (bleeding and clotting), NEUROTOXICITY, secondary infections, hypersensitivity

6

PCN: spectrum, clinical uses

spectrum: Gram + (cocci, rods, anerobes), Gram - (cocci), spirochete.
uses: syphilis, gangrene

7

PCN: 3 types and spectrum differences

natural
antistaph (B Lactamase resistant): add MSSA, Streptococcus A and B
extended spectrum: Add gram - (can get through outer membrane) .
-->Amp/Amox: add + and -, subtract MSSA
-->Piper/Tic: add + (including pseudomonas, Klebsiella, Enterobacter)

8

PCN- natural group

"Natural Voluptous Girls Benza-yonce"
G, V, Benzathine

9

PCN- AntiStaph

"you take drug test for staff?" - "Nah im chillin, Oxy and Meth Dictate"
Naficillin
Oxacillin
Methacillin
Dicloxacillin

10

PCN- extended spectrum

Ampicillin/Amoxicillin
Pipercillin/Ticarcillin

11

Abx that attack cell wall synthesis

Beta Lactams (PCNs, Cephalosporins, Monobactams, Carbopenems)
-->Beta Lactamas inhibitors ("CAST": Clavulanic Acid,
Avibactam, Sulfabactam, Tazobactam)

Glycopeptides
Bacitracin
Fosfomycin
cycloserine (not as important)

12

Abx that attack protein synthesis

50s subunit: Macrolides, Clindamycin, Streptogramins, Oxazolidones
30s Subunit: Tetracyclines, Aminoglycosides

13

Abx that attack cell membrane integrity

Polymixins
Daptomycin

14

Abx that attack metabolic pathways (folate synthesis)or action

sulfanomide, trimethoprim
(PABA- folate- purines)

15

Abx that attack Nucleic acid synthesis

fluoroquinolones and metronizadole - DNA
Rifampin- RNA

16

only place in the body where you shouldnt have normal flora

lungs

17

common offenders with no cell wall (aka can't use cell wall attacker)

TB, mycoplasm pneumoniae, chlamydia pneumoniae, legionella pneumoniae

18

difficult areas to determine if normal flora is a problem

sputum, urine from women (dirtier areas)

19

empiric treatment

Selecting an agent to treat an ill patient based on presumed infection (signs and symptoms). dont wanna wait for C&S- either critically ill pt, immunosuppressed, easy to identify
=treat with broad spectrum right away, then maybe do C&S

20

min. inhibitory conc. vs. min bactericidal conc.

Minimum Inhibitory Concentration
Lowest antimicrobial concentration that prevents growth of an organism 24 hours after administration

Minimum Bactericidal Concentration
Lowest antimicrobial concentration that kills 99.9% of bacteria
minimum inhibitory conc- goes along with bacteriostatic - can use these at lower agents and increase it to become bactericidal

21

factors that affect effective conc of drug

Impacted by:
Capillaries ability to carry drug to tissue site

Natural barriers: CNS, placenta, vitreous body of eye

Blood Brain Barrier (BBB)- very tight junctions
For agent to cross BBB is must possess the following:
High lipid solubility
Low molecular weight
Low protein binding

22

reasons to give drugs parenterally

-For increased bioavailability
Drug is avoiding first pass metabolism by liver
-Need increased absorption due to gut malabsorption issue
-Necessary for high concentrations (meningitis & endocarditis)
-Also give IV or IM if can’t take oral medications
Vomiting or drug not absorbed orally

23

when can you change IV or oral medication?

General rule: when seeing signs of improvement, fever down and focal symptoms better, and have an equivalent oral antibiotic then switch to it
A popular time to do this is once culture results back (48 hours) as culture will help tell you which oral antibiotic will be effective

24

conc dependent killing, time dependent killing, postantibiotic effect

-Concentration-dependent killing
Once daily dosing to achieve high peak levels
Leads to rapid killing of pathogen
Ex. Aminoglycosides, fluoroquinolones

-Time-dependent (concentration-independent) killing
Multiple doses or continuous IV infusion
Increased efficacy of antimicrobial when the blood conc. remain above MIC (min inhib conc.) for extended periods of time to kill more bacteria
Beta-lactams, macrolides

-Postantibiotic effect
Persistent suppression of microbial growth after antibiotic levels fall below MIC.
Ex. Aminoglycosides, fluoroquinolones

25

mechanisms of resistance to antibiotics (by bacteria)
(4 main)

Destruction or Inactivation of Drug
Mutation of Target Site
Efflux of Drug
Genetic Transfer
-Conjugation
-Transformation
-Transduction

26

common contributors to hypersensitivity (drug allergy)

beta lactams and sulfas

27

3 complications of antibiotics therapy

hypersensitivity, toxicity (adverse effect), superinfection

28

B lactamase inhibitors: function

Beta lactamases:source of resistance.
used in combo with abx
inhibit the enzyme produced by the bacteria (w/abx)= bacteria will not be as resistant to the antibiotic.

Available in fixed combinations (ex. amox/clav=augmentin)
The dose is based on the strength of the primary antibiotic – not the beta lactamase inhibitor.

29

Beta Lactamase inhibitors

"CAST"
Clavulanic Acid
Avibactram (w/ ceftazidime)
Sulfabactam
Taxobactam

30

cephalosporin generation categorizing

Five generations based on when they are made & what they kill.

When a significant modification was made to the group that really changed the spectrum it was called a new generation.

First generation the oldest
Currently on fifth generation