Diebel Drugs! Flashcards
what is the central structure of cell wall inhibitors?
thiaziolidine ring + beta lactam ring + variable side chain
How do cell wall inhibitors stop cross linking of cell wall?
Bacteria pick up beta lactam ring. Thaizolidine ring gets locked into active site. Covalenet bond forms in active site and blocks transpeptidation.
What cell wall inhibitors are penicillinase resistant?
Dicloxacillin, Nafcillin, Methicillin, Oxacillin.
What cell wall inhibitors are antipseudomonal?
Piperacillin
Ticarcillin
How do cephalopsorins work?
Have distinct outside ring from pencillin - trick transpeptidase into picking it up and blocks cell wall formation.
Cephalosporins
absorption?
Renal clearace?
cross reactive?
poorly absorbed in small intestine.
Renal clearance except ceftriaxone.
Yes, do not take with strong hypersensitivity to penicillin.
Side effects of cephalosporins:
Pseudomembrane colitis.
Hypersensitivity.
+ coombs test - type II hypersnesitivity
1st generation cephalosporins
cefazolin
cephalexin
work against gram + cocci, some gram negative
2nd gen Cephalosporins
Cefaclor, Cefoxitin, Cefuxorxime
more broad - target more gram negative.
3rd gen Cephalosporins
Cefotaxime, Ceftazdime, Ceftriaxone
gram+, gram -, enteric bacteria w/beta lactamses.
4th gen Cephalosporins
cefepime
gram +, gram - , pseudomonas
5th gen Cephalosporins
Ceftaroline
MRSA
What do the cephalsporins not cover against?
LAME
L=listeria
A = atypicals (mycoplasma, chlaydmia)
M = mrsa except fifth
E = enterococci
How do carbapenems work?
block transpeptidase rxn and cell wall formation.
BacteriCIDAL.
when are carbapenems used
in hosptials whne other antibiotics aren’t working. Broad spectrum.
Beta-lactamase resistant.
Side effects of carbapenems:
GI distress.
Skin rash.
CNS toxicity.
cross reactive w/penicillins
Eosinophilia.
Seizures in elderly.
Why must imipenem be adminstered w/cilastatin?
block renal dihydropeptidase I to decrease inactivation of drug.
How does vancomycin work?
inhibits cell wall synthesis by binding to D-alanyl-D-alaine precursors.
Blocks peptidoglycan polyermization - transglycoslyation.
Side effects of vanco:
Red man syndrome - flushing, hypotension, pruritis
Renal function impairment
How does linezolid work?
binds to 50S subunit of ribosome - prevents it from being put together & blocks initiation complex formation.
CIDAL but static at low concentrations.
What does linezolid work against?
gram +
MRSA
VRE
4 MRSA if vanco fails
side effects of linezolid
Bone marrow suppression
GI intolerance
Headache
Resistance to linezolid?
point mutation in ribosomal RNA.
How do tetracyclines work?
Stop protein synthesis by binding to 30S subunit and preventing attachment of aminoacyl-tRNA.
STATIC.
limited CNS penetration
What are tetracycline drugs used for?
Boreelia burgdorferi.
Mycoplasma pneumonia.
Intracellular bugs - ricketsia, chlamydia.
Side effects of tetracyclines:
NOT w/pregnancy.
not with antacids or milk.
GI distress.
Teeth discoloration and bone growth stopping in kids.
Photosensitivity.
How do macrolide drugs work?
Inhibit translocation by binding to the 23S RNA of the 50S subunit - prevents elongation of the peptide chain
Bacteriostatic.
What tetracycline drug can be used with renal failure?
Doxycyline - it’s fecally eliminated
What is the resistance of tetracyclines?
Decreased uptake.
increased efflux by bacterial plasmid encoded transport pumps.
What are examples of macrolide drugs?
Azithromycin
Clarithromycin
Erythromycin
What do macrolides work against?
Atypical pneumonias - mycoplasma, Chlamydia, Legionella.
STIs - chlmaydia
Gram + cocci (strep infections w/penicilin allergy)
Bordetella pertussis.
What is the resistance of macrolides?
methylation of 23S rRNA binding site that prevents drug binding.
Side effects of macrolides
GI intolerance.
Arrhythmia - prolonged QT
hearing loss (reversible)
metallic taste.
increase concnetration of theophylline and coagulants.
clarith and eryth inhibit cyp450.
how do quinolones work?
Bind to bacterial DNA gyrase and topoisomerase IV - leads to formation of double strand breaks
preents relaxation of + supercoils
infterferes with separation of DNA into daughter cells during cell division.
CIDAL
What are quinolones used for?
gram negative bacilli.
enterobacteriaceae
Haemophilus.
Neisseria
Moraxella catarhalis.
p. aeruginosa (levofloxacin)
Staphylococci.
What are teh side effects of quinolones?
GI AE.
not w/pregnancy
confusion - pentrates CNS.
C. diff
candida vaginitis.
cartilage damage
tendon rupture in > 60 + prednisone
What shouldn’t you take while on quinolones?
antacids - chelates cations like Ca, Fe, Al, and Zi
Avoid diary and Ca fortified juice.
How do oseltamivir and zanamivir work?
Inhibit NA enzyme leading to decreased virus release. Must use early in infection.
Oseltamavir
Use (age)
Side effects
1 year older and with pregnancy
GI, headache, fatigue.
Who can you use Zanamivir with?
7 or older
not w/COPD or asthma
