Antiinfective therapy + Beta lactam Flashcards
Gram Pos mnemonic
gram Pos–Purple–^Peptidoglican–Penicillin
Gram Neg mnemonic
gram Neg–Not Nice polysacaride–eNdotoxin
How to differentiate staph and strep (2)
Staph: catalase + , grape clusters
Strep: catalase -, diplococci/chains
Gram-neg pathologic think
Aerobic bacilli
Anerobic think
deep abscess (ie bacteroides)
Glucose fermenters think
like the gut (Enterobacteriaceae)
3 categories of anti-infectives: PED
- Prophylactic therapy: prevent infection
- Empiric therapy: treat suspectd infect’n–towd “most likely”
- Definitive therapy: treat known infective agent-culture-> sensitivity
Teenager CAP, pathogen and treatment
- Mycoplasma,
- macrolide –> azithromycin
Antiinfective MO’s (5)
- inhibition of Cell Wall synthesis
- protein synthesis inhibitors
- Inhibition of nucleic acid replication and transcription
- Inhibition of synthesis of essential metabolites
- Plasma membrane injury
Cell Wall synthesis inhibitors (4)
- penicillin
- vancomycin
- cephalosporins
- bacitracin
Protein synthesis inhibitors (4) (bacteriostatic)
- Chloramphenicol
- erythromycin
- tetracyclines
- streptomycin
Nucleic acid replication inhibitors (2) (bacteriocidal)
- Quinolones
2. rifampin
Essential metabolite synthesis inhibitors (2)
- Sulfanilamide
2. Trimethoprim
Plasma membrane injury (1) (topical)
- Polymyxin B
fungi version of cholesterol in cell wall–helps hold wall together
ergosterol
spectrum of activity can be _______ or _______
wide or narrow
anaphylaxis and hives are:
Type I hypersensitivity rxn
Ways toxicity can happen: (3)
- extension of mehanism of action
- Unintended physiologic interaction
- Dose-related
an infection that occurs during or after treatment of another pre-existing infection–may result from the treatment itself or changes in I.S
secondary infection
a new infeciton occuring in a pt having a preexisting infection
Superinfection
Bacteria can resist action of antibiotics by: (4)
societal vs. patient level
- preventing access to target of antibiotic
- degrading antibiotic
- altering antibiotic
- rapid extrusion of antibiotic
DDDD for antibiotic resistance
- Disable – inactivation of the antibiotic (usually by a beta-lactamase
- Disguise – modification of target proteins (MRSA)
- Deter – impaired entry of antibiotic into bacteria
- Discharge – ejection of antibiotic by EFFLUX PUMPS
Guidelines for antiinfection use: study pg 15
Imp for Sanford Guide
- Don’t use antibiotic for COLONIZATION/ CONTAMINATION
- Use most narrow-spectrum agent appropriate for pt infection
- Use proper does
- Use shortest effective during of therapy
cell wall inhibitor–prevent cross-linking
beta-latam inhibitor–bactericidal by intervering w/ the trnaspeptidation rxn of bacterial cell wall synthesis
almost all beta-lactam’s end in ______ or ______ or start with______
-cillin (PCNs),
-penem
ceph-
Mechanisms of beta-lactam antibiotic drug resistance (2)
- inactivation of antibiotic by beta-lactame
2. modification of PBPs (penicillin binding protein)
beta-lactames won’t treat
MRSA–resistant to all 3 types of penicillins
will treat MSSA (methisilin sensitive Staph aureus)
beta-lactames excreted in active form in urine, so we should think…
- dose adjustmetns needed w/ renal impairments
2. can be used to treat UTI’s
penicillin classes
- natural penicillin (form directly form mold ex. PCN G & V)
- antistaph penicillins
- extended-spectrum penicillins
penicillin have _____ protein binding, doesn’t like to go into _____
high–,
CSF–w/ meningitis BBB not as function—> penicilin
Penicillin V (oral vs. parenteral G) _________ activity against Gram+ orgs, Gram - cocci, and non-beta lactamase producing anaerobes
GREATEST – resistance high though
Penicillin V have ______ activity agains Gram- _____
little,
rods
Penicillin V K (oral) (potassium pairing for less acid inactivation) indicated for
mild to moderate infections (strep throat, otitis media, impetigo)–because v bioavailablity
Penicillin V can be given with meals but _______ is _______ if given on an empty stomach
absorption is improved
Penicillin V ADR’s (3)
- GI disturbances
- Hypersensitivity (allergy)
- Secondary infection
anti staff penicillin
methicillin
Main Gram+ w/ more Gram- coverage
Aminopenicillins (Extended-spectrum penicillins)
better at crossing porin channel
Amoxicillin
Good for ENT infections, GU, skin/skin structure infections, pneumonia, part of triple therapy for H. pylori
Amoxicillin–great against Streptococcal species
Use amoxicillin ______ and ampicillin_______
orally,
parenterally
Augmentin
Amoxicillin w/ Clavulanate ( Beta-lactmase inhibitor)
Amoxicillin + clavulante potassium
Augmentin–take at start of meal
Cephalosporins–generations?
1st -- good for Gram+ 2nd 3rd 4th -- best for Gram- 5th -- best for Gram+
Cephalosporins mode of action
same as other beta-lactams–not good on MRSA–bad on pseudomonas
Fifth generation Cephalosporin targets
MRSA–penetrates CNS plus 4th
VRE
vancomycin resistant enterococcus
Impetigo:
Group A strep:
Staph. Aureus:
- “honey crusted” lesions (non-bullous)
- Bullous
similar to other beta-lactam antibiotics – no cross-resistance btwn penicillins
Carbapenems (popular: imipenem) – hospitals and ICUs–LIVER TOXIC
new synthetic class of moncyclic beta- lactam–narrow spectrum–ONLY binds to PBP in Gram-neg aerobic bac
Monobactams–look at end of beta-lactan ppt for summarys!!!
