Antibiotics Flashcards
Penicillin G/V; MOA, use, AE
G = IV; V = oral
MOA - 1. bind penicillin0binding proteins (transpeptidases, involved in synthesis of the cell walls)
2. block transpeptidase cross-linking of peptidoglycan in cell wall
3. activate autolytic enzymes -> remodels cell wall
Use - mostly gram (+) coverage (S. pneumo, S. progenies, Actinomyces, group B strep, Clostridium, Listeria, Bacillus); gram (-) coverage (mainly N. meningitides) and spirochetes (T. pallidum)
AE - hypersensitivity reactions, hemolytic anemia
Penicillinase-sensitive penicillins; name, MOA, use, AE
Amoxicillin, ampicillin, aminopenicillin
MOA: same as penicillin
Use: extended spectrum penicillin - cover HEELPSS organisms: H. flu, E. coli, Enterococci, Listeria, Proteus mirabilis, Shigella, Salmonella
AE: hypersensitivity reactions, rash with mononucleosis
Penicillin-resistant penicillins; name, MOA, use, AE
Dicloxacillin, nafcillin, oxacillin, methicillin (can cause interstitial nephritis, so not used)
MOA: same as penicillin; penicillinase-resistant d/t large R group
Use: S. aureus (except MRSA)
AE: hypersensitivity reactions
Antipseudomonal penicillins; name, MOA, use, AE
piperacillin, ticeracillin, carbenicillin
MOA: same as penicillin
Use: pseudomonas spp. and gram (-) rods; susceptible to penicillinase
AE: hypersensitivity
beta lactase inhibitors; name, MOA, use
Clavulanic acid (use with amoxicillin, esp for otitis media), Sulbatam (use with ampicillin), Tazobactam (use with ticarcillin + piperacillin) MOA - protect antibiotic from destruction by beta-lactamase (penicillinase)
What are the organisms typically not covered by cephalosporins generation 1-4?
Organisms not covered by 1st-4th generation cephalosporins are LAME
Listeria
Atypicals (Chlamydia, Mycoplasma), MRSA, Enterococci
What is the MOA of all cephalosporins?
beta lactic drugs that inhibit cell wall synthesis (less susceptible to penicillinases)
1st generation cephalosporins: names, coverage, use
cefazolin, cefalexin
Coverage: gram + cocci, and PEcK - Proteus mirabilis, E. coli, Klebsiella
Use: UTIs, URIs, prophylaxis to S. viridian’s endocarditis (amoxicillin still 1st line), cephazolin used before surgery to prevent S. aureus wound infections)
2nd generation cephalosporins: names, coverage, use
cefprozil, cefaclor, cefoxitin, cefuroxime (pro fake fox fur)
Coverage: gram + cocci, HENS PEcK: H. influ, Enterobacter aerogenes, Neisseria spp., Serratia, Proteus mirabilis, E. coli, Klebsiella
Use - do not use to treat gonnorhea
3rd generation cephalosporins: names, coverage, use
ceftriazone, cefotaxime, ceftazidime, cefdinir
Coverage: S. pneumo, serious gram - infections resistant to other beta-lactams
Use: ceftriaxone - meningitis, gonorrhea (drug of choice for gram - meningitis; good to use in renal failure), disseminated Lyme disease
ceftazidine - pseudomonas
cefdinir - resistant causes of otitis media (1st line amoxicillin)
4th generation cephalosporins: names, coverage
cefepime
Coverage: gram (-) organisms with increased activity against pseudomonas and gram (+) organisms
5th generation cephalosporins: names, coverage, use
ceftaroline
Coverage: broad gram + and gram - organisms coverage
Unlink 1st-4th gen, has coverage against: Listeria, MRSA, and Enterococcus faecalis
Does not cover pseudomonas
What are the common AE of cephalosporins?
hypersensitivity reactions, disulfiram-like reaction, increased nephrotoxicity of ahminoglycosides
Aztreonam MOA, use, AE
MOA - prevents peptidoglycan cross-linking by binding to penicillin-binding protein 3; synergistic with ahminoglycosides; no cross-allergy with penicillins
Use - gram (-) rods only (E. coli, Klebsiella, Pseudomonas, Serratia); no activity against gram + rods or anaerobes; use in pts with penicillin allergy or those with renal insufficiency that cannot tolerate aminoglycosides
AE - well tolerated
Carbapenems - names, MOA, use, AE
Names - imipenem (with cisplatin), meropenem, ertapenem, doripenem
MOA - bind to penicillin binding proteins
Use - wide coverage; gram + cocci, gram - rods, and anaerobes; pseudomonas coverage but NOT MRSA
AE - GI distress, skin rash, seizures (merepenem has decreased risk of seizures)
Why is imipenem always administered with cisplatin?
cisplatin inhibits dehydropeptidase I in the kidneys, which inactivates imipenem in the renal tubules
Vancomycin MOA, use, AE
MOA - binds to D-ala D-ala portion of cell wall precursors -> inhibits cell wall mucopeptide formation -> inhibits cell wall glycopeptide polymerization
Use - gram + bugs only, used for coag-neg staph endocarditis; MRS, S. epidermidis, sensitive Enerococcus species, and C. diff (oral dose for pseudomembranous colitis)
AE - NOT trouble free - nephrotoxicity, ototoxicity, thrombophlebitis; Red man syndrome - d/t nonspecific mast cell degranulation
How does an organism develop resistance to vancomycin?
amino acid modification of D-Ala D-Ala to D-Ala D-Lac
A patient is receiving an IV infusion of an antibiotic and the nurse calls you when his face becomes flushed 15 minutes after the infusion started. What is the treatment for this patient?
- stop the infusion of vancomyin
- pretreat with antihistamines
- start the infusion again but slower
Linezolid MOA, use, AE
MOA - binds 23S RNA on 50S subunit and inhibits initiation
Use - MRSA, VRE
AE - serotonin syndrome
Which antibiotics are 30S inhibitors and which are 50S inhibitors?
Buy AT 30, CCEL (sell) at 50
30S - Aminoglycosides, Tetracyclines
50S - Chloramphenicol, Clindamycin, Erythromycin (macrolides), Linezolid
Tetracyclines names, MOA, Use, AE
Names - tetracycline, doxycycline, minonycline, demeclocycline MOA - bind to 30S subunit and prevent attachment of tRNA; doxycycline can be used in renal failure; cannot take tetracyclines with milk or antacids Use - VACUUM THe BedRoom - vibrio cholera - acne - chlamydia - ureaplasma urealyticum - mycoplasma pneumonia - tularemia - H. pylori - Borrelia burgdorferi - Ricketssia AE - discoloration of teeth and inhibition of bone growth in children, photosensitivity, C/I in pregnancy
Aminoglycosides names, MOA, Use, AE
Names - gentamicin, neomycin, amikacin, tobramycin, streptomycin
MOA - irreversible inhibition of initiation complex by binding 30S subunit; require O2 for uptake (ineffective against anaerobes)
Use - gram - rods; synergistic with beta-lactam Abs; neomycin can be used for bowel surgery
AE - nephrotoxic, ototoxic (esp with loop diuretics), teratogenic (NOT)
Macrocodes names, MOA, Use, AE
Names - azithromycin, clarithromycin, erythromycin
MOA - bind 23S rRNA of the 50S ribosomal subunit -> inhibit protein synthesis by blocking translation
Use - PUS
- pneumonia (atypical) - mycoplasma, chlamoydophila, legionella
-URI (S. progenies, H. influ)
-STD (chlamydia, gonnorhea)
AE - QT prolongation, acute cholestatic hepatitis (erythromycin), eosinophila, increase serum concentration of theophylline and oral anticoagulants (warfarin)
