Antibiotics for Final Flashcards
Penicillin
MOA = Bind to penicillin binding proteins which are transpeptidases that make the cell wall.
Spectrum = Gram +
Bactericidal
Benzathine = subcutaneous injection for longer half life.
*Anaphalaxis is a concern
Penicillinase
Enzymes that break down penicillin. Mechanism of resistnace
Nafcillin & Dicloxacillin
Same as penicillin but has larger R group which blocks penicillinase activity
MSSA usage
Beta-lactamase inhibitors
Clavulanate
Sulbactam
Tazobactam
Ampicillin and Amoxicillin
B-lactam with more gram negative coverage.
Amp + Sulbactam & Amo + Clavulanate
Associated with C diff.
Ticarcillin and Pipercillin
B- lactam that can be used against pseudomonas.
Broader action against gram -
Penicillin Allergy
3-10% of US
Only 5-10% react the second time
0.05% anaphylactic shock –> Epi
via hapten-protein comples –> IgE
Aztreonam
Beta-lactam with no cross allergic responses
Gram negative rods? / Inactivated by beta-lactamases
Cephalosporins
B- Lactam Less Susceptible to penicillinases
Dosage adjustment in renal insufficiency
Cefazolin
1st generation cephalosporin.
Gram +
Surgical prophylaxis
Doesn’t cross B-B barrier
Cefoxitin and cefuroxime
2nd generation cephalosporin
Use right before surgery
Doesn’t cross B-B barrier
Disulfiram-like reaction with EtOH = Hangover!!!
Ceftriaxone and cefotaxime
3rd Gen Ceph Use for serious gram - Can cross blood brain barrier ***Brain infections/Meningitis*** Strong association with C. diff Kelates calcium
Cefepime
4th generation (1st + 3rd) Broadest spectrum ceph = Gram +/- and pseudomonas Good for empiric therapy
Ceftraroline
5th generation
Kills MRSA
Carbapenems - imipenim/cilastatin and meropenem
B-lactam
Broad spectrum but no MRSA
**cilastatin used to decrease nephrotoxicity
Now have Klebsiella pneumonia carbapenemase (KPC) superbugs
Genral Notes for Beta - Lactam
Seizures
Assume cross alleginicity
Monitor renal clearance
Vancomycin
MOA = Binds D-Alanyl-D-alanine terminus of cell wall precursor. Inhibits transglycolase.
Spectrum = gram + and MRSA
Oral vanco is poorly absorbed
Good for empiric
“Say no to Vanco :)”
Side effects = red man syndrome (hypersensitivity), nephrotoxicity (adjust dosage in renal insufficiency)
Now have VRE!!!
VRE resistance mechanism to Vanco
replac D-alanyl-D-alanine w/ D-alanyl-D-lactate or D-Alanyl-D-Serine
Bacitracin
MOA= inhibits elongation of cell wall (Not B-lactam) –> prevents dephosphorylation of Bactroprenol
Usage= poor bio availability –> topical, ophthalmic, and dermatologic
SA= Neprotoxic when given IM
low resistance
Polymyxin B
MOA= Binds to LPS making holes
Spectrum = Multidrug resistant gram negative bacilli
Used in combination iwth other ABs for entry
SA = Nephrotoxicity
Low resistance
Daptomycin
MOA = Depolarization of cell membrane
Spectrum = Gram + (Saved for VRE and Vanco resistant MRSA)
Side effects = pulmonary accumulation
Resistance = addition of positively charged lysine to cell surface repels the positively charged drug.
30s inhibitors
Aminoglycosides and tetracycline
50s inhibitors
linezolid, macrolides, chloramphenicol, clindamycin, quinupristin/dalfopristin
Initiation blockers
linezolid and aminoglycosides
Elongation blockers
aminoglycosides, tetracycline, macrolide, chloramphenicol, clindamycin, q/d
Protein synthesis inhibitors = static or cidal
static except aminoglycosides or certain combinations
Which inhibit mitochondrial ribosomes and cause bone marrow suppression
TLC Tetracycline, Linezolid, and chloramphenicol
*genetic variation here
Linezolid
MOA =Binds 50s and prevents formation of initiation complex
Spectrum = Gram + including MRSA and VRE
Resistance = altered 23s binding site –> no cross resistance :)
SA = Bone marrow suppression (tLc), inhibits MAO –> seratonin syndrom with SSRIs (hallucinations, increase heart rate, agitation, and nausea)
Aminoglycosides - gentamycin, neomycin, amikacin, tobramycin, and streptomycin (GNATS)
MOA - Bacteriocidal -prevents initiation, causes mRNA misreading, and early termination.
Spectrum = gram negative aerobes (Usually used in combo)
Resistance = failure to enter cell wall –> cotreat with cell wall inhibitor (genrally ampiciliin/amoxicillin), enzymes that inactivate the drug
Amikacin –> pseudomonas
Concentration dependent killing!
Adverse side effects = tubular necrosis, ototoxicity, hearing loss in pregnancy (class D)
Notes = IV administration and excluded from CSF
Concentration dependent killers
aminoglycosides and fluoroquinolones
time dependent killers
beta lactams and vanco
Tetracylcines - tetracycline, doxycycline, democlocycline and minocycline
MOA = binds 30s preventing attachment of aminoacyl tRNA Spectrum = B. burgdorferi, H. pylori, and Mycoplasm pneumoniae due to resistnance Resistnace = decreased uptake (intinsic), increased efflux*, altered ribosomal target Adverse effects: Kelates cations, photosensitivity, discoloration of teeth, pregnancy class D
Chloramphenicol
MOA = binds 50s preventing peptidyltransferase
Spectrum = extened, but little use due to side effects
Resistance = acetyltransferase alters drug = no binding
Adverse effects = TOXIC, Bone marrow suppression (tlC), Aplastic anemia, Gray baby syndrome (Class D)
Grey baby syndrome
Caused by chloramphenicol = premature infants lack UDP-glucuronyl transferase and decreased renal function leads to high drug levels –> cardio/pulmonary collapse
Macrolides - Erythromycin, azithromycin, clarithromycin
MOA = inhibits tranlsocation of 50s Spectrum = broad coverage or respiratory pathogens, Chlymidia (single dose) Upper respiratory infections Resistance = methylation of 23s (shared with clindamycin and q/d) Adverse effects = hepatic failure, prolonged QT, inhibits cyp450, Clarithromycin = pregnancy class D
Clindamycin
MOA = Blocks translocation of 50s
Spectrum = gram + including anaerobes –> acne
Resistance = mutation of ribosome / methylation of 23s (cross resistance with macrolides and q/d)
Adverse effects = Hypersensitivity, C. Diff!
Streptogramins - Quinupristin/ Dalforpristin
MOA = Binds 50s to inhibit tranlocation, cobined action is bactericidal
Spectrum = reserved for MRSA and VRE
Resistance = Enzymes that incactivate, Efflux pumps, and methylation of 23s (cross resistance with macrolides and clindamycin)
Adverse effects = arthralgias and myalgias, inhibits cyp450
Mech of resistance = decreased uptake
Tetracyclines, Sulfonamides, Aminoglycosides, and Chlormaphenicol (The Stupid Ass Coach)
Mech of resistance = Increased efflux
FAT SCAMS (written as cross) Fluoroquinolones, Aztreonam, Tetracylines (most important), Sulfonamides, cephalosporins, macrolides, streptogramins
Mech of resistance = altered target
Like everything (need acronym or exclusion list)
Mech of reistance = Upregulation of substrate
Sulfonamides (increased PABA synthesis)
Mech of resistance = enzymatic inactivation
MC STAB MC (MCs are incactivating each other to win the rap battle duh! ) = Macrolides Clindamycin - Streptogrammins Tetracylines Aminoglycocidess B-lactamases - Metronidazole Chloramphenicol
Rare resistance
Bacitracin, polymyxins, nitrofurantoin, metronidazole
Rifampin
MOA = bactricidal, binds RNA pol and blocks elongation
Spectrum = TB, extended (RIPES due to high resistance)
Resistance = intrinsic due to binding, and aquired due to rpoB mutations preventing binding (Inhibited Binding)
Adverse effects = orange red fluids, Induction of CYP3A4 (faster warfarin metabolism)
Fidaxomicin
MOA = bacteriocidal Inhibits RNA pol
Spectrum = Narrow Gram + anaerobes - C. diff!
Side effects = Few due to low absorbtion
Resistance = point mutation in RNA pol in vitro (no en vivo yet!)
Fluoroquinolones - Ciprofloxacin, levofloxacin, and moxifloxacin
MOA - Inhibit topoisomerase (topo II in gram - and topo IV in gram +) Spectrum = broad, mycoplasm, hospital aquired pneumonia, UTIs (overperscribed) Resistance = Active efflux, mutations in topo Adverse effects = Chelates cations!, confusion and photosensitivity, C diff and candida vaginitis, Pregnancy class D (arthropathy)
Sulfonamides - Sulfamethoxazole
MOA = PABA analog
Resistance = change in dihydropterate synthetase, efflux, increased PABA production
Adverse effects = hypersensitivity –> Stevens-Johnson, crystalluria –> acute renal failure, Hemolysis in G-6=P DH deficiency, kernicterus (neurologic condition in severly jaundiced newborns
*Can compete for albumin –> adverse effects with warfarin and other drugs
Trimethoprim
MOA = Inhibits DHFR
Resistance = altered or increased DHFR, alternative metabolic pathways,
Adverse effects
GI upset
Bactrim = TMP and SMX
MOA = Sequential folate synthesis blockage Spectrum = broad treatment of UTIs, pneumocystis
Metronidzaole (Flagil)
MOA = electron sink --> free radicals --> DNA breaks Spectrum = anaerobes --> C diff, Protozoa Resistance = rare Adverse effects = pregnancy class D, Disulfiram like reaction with EtOH
Nitrofurantoin
MOA = inhibits synthesis of DNA, RNA, cell wall, and protein via ribosome destruction
Spectrum = Broad spectrum and rapidly excreted **UTIs
Resistance = Lack of resistance due to variety of processes
Adverse effects = vomiting and rash
Don’t use with Newborns
Chloramphenicol and Sulfonamides
Don’t Use in children
Techincal Foul if you use Tetracyclines or Fluoroquinolones
Don’t Use During Preganancy
Fuck Cunt Shit it’s the MCAT (Because the three worst swear words should be associated with that God-forsaken exam and its likely what you say if you accidently get pregnant) Fluoroquinolones, Chloramphenicol, Sulfonamides, Metronidazol Clarithromycin Aminoglycosides, Tetracyclines
Don’t use in elderly / adjust for renal function
FAB because old people say fab = fluoroquinolones, aminoglycosides and B lactams
Cause Hemolysis
Sulfonamides = aplastic anemia in g-6-p dh defeciency
Chloramphenicol too but not g6p related
What is coadministered with Penicillin
Probenicid (due to low half life of the drug)
