Overview of antimicrobials Part I, J Kinder, DSA Flashcards by Amanda Beach

Goal of prophylactic therapy

prevent infection or prevent dangerous disease in those already infected

How well did you know this?

Not at all

Perfectly

what is preemptive therapy

targeted therapy in high risk patients who are asymptomatic but have become infected

How well did you know this?

Not at all

Perfectly

what is empiric therapy

provide antimicrobial therapy to a symptomatic patient without identification of infecting organism

How well did you know this?

Not at all

Perfectly

what is definitive therapy

infecting organism is known

streamlined therapy based on susceptibility and duration

How well did you know this?

Not at all

Perfectly

post Tx suppressive therapy

cover patient with antimicrobial therapy at lower dose when infection has not been completely eradicated and immunological or anatomical defect still present which lead to original infection

How well did you know this?

Not at all

Perfectly

What is the most valuable immediate test for susceptibility of microbial agent

gram stain

How well did you know this?

Not at all

Perfectly

What is MIC

minimum inhibitory [ ]

lowest [ ] of drug required to inhibit growth

How well did you know this?

Not at all

Perfectly

disk diffusion method for determining suscebtibility can qualitatively measure what

susceptible or Resistant

not MIC

How well did you know this?

Not at all

Perfectly

methods to determine MIC

dilution tests and optical diffusion

How well did you know this?

Not at all

Perfectly

What is narrow specrum

antibacterial acts on single or limited group microorganisms

How well did you know this?

Not at all

Perfectly

what is extended spectrum

active against gram + bacteria but also against significant number of gram - bacteria

How well did you know this?

Not at all

Perfectly

what is broad spectrum

act on wide variety bacterial species (both gram + and -)

How well did you know this?

Not at all

Perfectly

What is bacteriostatic

arrests growth and replication of bacteria

protein synthesis inhibitors

How well did you know this?

Not at all

Perfectly

what is bactericidal

kills bacteria

How well did you know this?

Not at all

Perfectly

types of bactericidal killing

[ ] dependent (inc [ ] inc killing)

time dependent )activity continues as long as serum [ ] above minimum bacterial [ ])

How well did you know this?

Not at all

Perfectly

what common antibiotics are concentration dependent bactericidals

aminoglycosides and fluoroquinolone

How well did you know this?

Not at all

Perfectly

what are common antibiotics that are time dependent bactericidals

B lactams and vanco

How well did you know this?

Not at all

Perfectly

What are common antibacterial targets

cell wall synthesis
cell membrane synthesis
synthesis 30S and 50S ribosomal subunits
nucleic acid metabolism
function of topoisomerases
folate synthesis

How well did you know this?

Not at all

Perfectly

What are 2 factors assoc with antimicrobial R

evolution

clinical/environmental practices

How well did you know this?

Not at all

Perfectly

What are the R mechanisms

reduced entry of antibiotic
enhanced export antibiotic
release microbial enzymes that kill antibiotic
alteration of microbial proteins that transform pro-drugs to the effective moieties
alteration of target proteins
development of alternative pathways to those inhibited by antibiotics

How well did you know this?

Not at all

Perfectly

penicillin structure

thiazolidine ring connected to B-lactam ring attached to side chain

what determines susceptibility of penicillins

side chains

MOA of penicillins

inhibit transpeptidation reaction, last step in peptidoglycan synthesis
Penicillin binding proteins remove terminal D alanine
B lactams are analogs of D-ala D-ala so bind PBP and prevent their crosslinking
leads to cell autolysis

How does R happen to penicillins

structural differences in PBPs and dec PBP affinity for B lactams
active efflux pumps
drug destruction!!
inactivation by B lactamases

what are aminopenicillins used for

extended spectrum, usually given with B lactam inhibitor

What are the aminopenicillins

ampicillin (+/-sulbactam) | amoxicillan (+/-clavulanic acid)

Therapeutic use of aminopenicillins

URI (S pyogenes, S pneumoniae, H influenzae, sinusitis, otitis media, enterococcal infections)

What type of spectrum are anti-pseudomonal penicillins and what are they types

extended spectrum ticarcillin (+/-clavulanic acid) piperacillin (+/- tazobactam)

Therapeutic use of anti-pseudomonal penicillins

serious gram - infections, hospital acquired pneumonia, immunocompromised patients, bacteremia, burn infections, UTI

What are the adverse effects of anti-pseudomonals

allergic rxns, anaphylaxis, interstitial nephritis (rare), nausea, vomiting, mild-severe diarrhea, pseudomembranous colitis

cephalosporins have same MOA and R as what class of antibiotics

penicillins

cephalosporins do not have activity for what microbes

MRSA, listeria or enterococci

activity of 3rd generation cephalosporins

less active against gram + | more active against enterobacteriae

What drugs are 3rd generation cephalosporins

Ceftriaxone, ceftazidime

Tx use of 3rd generation cephalosporins

DOC serious gram - infections (Klebsiella, enterobacter, Proteus, Providencia, Serratia, Haemophilus)

ceftriaxone is DOC for what

all forms gonorrhea and severe lymes disease, meningitis

activity of 4th generation cephalosporins

extends spectrum beyond 3rd generation | serious hospitalized patients

What drugs are 4th generation cephalosporins

cefepime

Therapeutic use of cefepime

empiracal Tx of nosocomial infections

adverse effects cefepime

1% cross reactivity to penicillins, diarrhea, intolerance to alcohol

MOA and R carbapenems is similar to what other drug class

penicillins

spectrum of carbapenems

aerobic and anaerobic microorganisms, gram +, excellent against enterobacteriacae, PSeudomonas, Acinetobacter

Therapeutic uses of carbapenems

UTI, lower RTI, intra-abdominal, gynecological, SSTI, bone and joint infections ALL IV or IM

what is beneficial about ertapenem

longer half life which allows for once daily dosing

Adverse effects of carbapenems

nausea/vomiting, seizures, HS

MOA glycopeptides

inhibits cell wall synthesis binding with high affinity to D alanylD alanine terminal Unable to penetrate outer membrane gram - bacteria

Bacterial Resistance of glycopeptides

alteration of Dalanyl D alanine to D alanyl D lactate or serine

spectrum of glycopeptides

broad gram + coverafe inclusing MRSA, MRSE | all gram - and mycobacterium resistant

Therapeutic use of glycopeptides

osteomyelitis, endocarditis, MRSA, strep, enterococci, CNS infections, bacteremia, orally for Clostridium difficile!

adverse effects glucopeptides

macular skin rash, chills, fever,rash red man synfrome from rapid infusion release of histamine from toxic effect vanco ototoxicity and nephrotoxicity