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128 Cards in this Set
- Front
- Back
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What drugs primary mechanism of action is inhibition of cell-wall synthesis?
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Penicillins, cephalosporins, imipenem/meropenem, aztreonam, vancomycin
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What is the primary mechanism of action of aminoglycosides, chloramphenical, macrolides, tetracyclines, streptogramins, linezolid?
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Inhibition of bacterial protein synthesis
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What drugs primary MOA is inhibition of nucleic synthesis?
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Fluoroquinolones, rifampin
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What is the primary MOA of sulfonamides, trimethoprim, pyrimethamine?
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Inhibition of folic acid synthesis
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What are the primary mechanism of resistance to penicillins and cephalosporins?
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Production of beta-lactamases, which cleave the beta lactam ring structure: change in penicillin-binding proteins (PBPs)
KNOW WHERE ON ON THE MOLECULE THIS ENZYME ACTS |
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What drugs primary mechanism of resistance involves the formation of enzymes that inactivate drugs via conjugation reactions that transfer acetyl, phosphoryl, or adenylyl groups?
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Aminoglycosides (gentamicin, streptomycin, amikacin, etc.)
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What is the primary mechanism of resistance to macrolides (erythromycin, azithromycin, clarithromycin, etc.) and clindamycin?
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Formation of methyltransferases that alter drug binding sites on the 50S ribosomal subunit
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What drugs primary mechanism of resistance involves increased activity of transport systems that "pump" drugs out of the cell?("bacterial pump")
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Tetracyclines
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what is the primary mechanism of resistance to sulfonamides?
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Change in sensitivity to inhibition of target enzyme; increased formation of PABA; use of exogenous folic acid
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What drugs primary mechanism of resistance involves change in sensitivity to inhibition of target enzyme; increased activity of transport systems that promote drug efflux?
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Fluoroquinolones
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what is the primary mechanism of resistance to Chloramphenical?
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Formation of inactivating acetyltransferases
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Are cell-wall synthesis inhibitors - bactericidal or -static?
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bactericidal
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Penicillins primary MOA
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interact w/ penicillin cytoplasmic membrane-binding proteins (PBPs) to inhibit rxns involved in cross-linking, (final steps in cell-wall synthesis)
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What are the 2 mechanisms of resistance to penicillin?
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1. pencillinases (beta-lactamases) break lactam ring structure
2. change in PBPs |
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What subgroup of Penicillin has a very narrow spectrum and is beta lactamase resistant (not cleaved by beta lactamase enzymes)?
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nafcillin, methicillin, oxacillin - think anti-staph drugs (not MRSA)
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VHY***
What subgroup of Penicillin has a narrow spectrum and is beta lactamase sensitive? |
***penicillin G and V
(Gram + cocci - streptococci, pneumococci, meningococci, ***Treponema pallidum - syphillis, benzathine PENG) |
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VHY***
What subgroup of Penicillin has a broad spectrum and is beta lactamase sensitive? |
ampicillin and amoxicillin
gram + cocci (not staph), E. coli, H. influenza, ***Listeria monocytogenes (Amp DOC), Borrelia burgdorferi (amox), H. pylori (amox) -activity enhanced if used in combo w/ inhibitors of beta lactamase: clavulanci acid, sulbactam |
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What subgroup of Penicillins are extended spectrum, antipsuedomonal, beta-lactamse sensitive with increased activity against gram neg. rods?
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ticarcillin, piperacillin, azlocillin
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What penicillin family of drugs do you NOT have to adjust with renal failure?
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nafcillin, oxacillin - eliminated largely in bile.
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What are the main SE's with Penicillin?
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Hypersensitivity (I-IV). Assume complete cross-allergenicity b/w penicillins.
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What drugs are considered pencillinase inhibitors?
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clavulanic acid and sulbactam
Suicide inhibitors - irreversibly inhibit resistant enzymes (ex - inhibit the actions of beta lactamases) |
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Cefzolin and cephalexin are considered what generation of cephalosporins?
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First generation.
Narrow spectrum - gram pos. cocci (not MRSA). Think PEcK: Proteus, E. coli, Klebsiella pneumoniae Use - surgical prophylaxis |
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Cefotetan, cefaclor, cefuroxime...
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2nd generation cephalosporins
increasing gram-neg. coverage, including some anaerobes Cefuroxime can enter CNS |
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3rd generation cephalosporins...
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***Ceftriaxone (IM), cefotaxime (parenteral), cefdinir and cefixime
Very broad spectrum - gram-pos. and gram-neg cocci plus many gram-neg rods Most enter CNS;management of meningitis (think ceftriaxone) |
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Fourth generation cephalosporin...
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Cefepime (IV)- very wide spectrum; resistant to most beta-lactamases.
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Organism not covered by cephalosporins are L.A.M.E.
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Listeria monocytogenes
Atypicals (ex.chlamydia/mycoplasma) MRSA Enterococci |
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What inhibits active tubular secretion of penicillins and cephalosporins?
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Probencid
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What the SE's assoc. with cephalosporins?
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Hypersensitivity - assume cross-allergenicity b/w cephs and penicillins
other - hypothrombinemia |
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What is the MOA for imipenem, meropenem, and ertapenem?
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same as cephs and penicillins (bind to PBP's, inhibit cross-linking)
***resistant to beta-lactamases |
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What is the spectrum of activity of imipenem, meropenem, and ertapenem?
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Broadest spectrum of antibiotics available.
Important in-hospital agents for empiric use in life threatening infxns. Only used by IV |
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These drugs (imipenem, meropenem, and ertapenem)undergo what type of elimination?
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Renal elimination - decrease dose in renal dysfunction
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What are the SE's assoc. with imipenem, meropenem, and ertapenem?
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GI distress, drug fever, CNS effects
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What IV drug is used only for gram neg. rods?
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Aztreonam - same MOA as cephs and penicillins, resistant to beta-lactamases.
No cross-allergenicity w/ cephs and pens |
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What is the drug of choice for MRSA?
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Vancomycin - DOC for MRSA; also used for enterococci and C. diff
MOA - binding at the D-ala-D-ala pentapeptide to sterically hinder the trasglycosylation rxns involved in elongation of peptidoglycan chains. Does NOT interfere w/ PBP's (penicillin binding protiens). |
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When is vancomycin used by IV?
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As a backup drug for Clostridium difficile (backup to metronidazole).
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What are VRSA, VRE, and VREF?
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Vancomycin resistant strains...
SA - staph aureaus E - enterococcal EF - enterococcal facium |
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What are the SE's assoc. w/ vancomycin?
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***Red man syndrome (histamine release - flushing rxn)
Ototoxicity/Nephrotoxicity |
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What drugs are assoc. w/ nephrotoxicity***?
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AmiNOglycosides, VaNcOmycin, amphotericin B, Cisplatin, Cyclosporine
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What are the sites of action for the inhibitors of protein synthesis?
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1. tRNA at A site goes to vacant P site...(inhibited by Macs)
2. New tRNA enters A site ...(docking step inhibited by Tets) 3. Transfer of peptidyl tRNA from P to A...(peptidyl transferase inhibited by chloramphenical) |
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What antibiotics inhibit protein synthesis at the 30s site?
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Aminoglycosides & Tetracyclines
...eveything else is at the 50s site (Linezolid, dalfopristin/quinupristin, chloramphenicol, macrolides, clindamycin) |
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Are aminoglycosides bacterialstatic or 'cidal?
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bactericidal - ***need O2 to get into bacteria (so anaerobes are innately resistant)
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What is the spectrum for aminoglycosides?
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gram neg. rods;
***gentamicin tobramycin amikacin streptomycin used in TB, and DOC for bubonic plague and tularemia |
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What SE's are assoc. w/ amiNOglycosides?
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Nephrotoxicity/Ototoxicity
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Are Tetracyclins (Tets)bacteriostatic or 'cidal?
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bacteriostatic
broad spectrum antibiotic w/ good activity vs chlamydia and mycoplasmal species, H. pylori, ***Ricketsia, B. burgdorferi, brucella, vibrio |
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What is used as a backup to penicillin G in syphillis?
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Tetracyclines
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What specific Tet. has more activity overall than tetracyclin HCl and is useful in prostatis b/c it reaches high levels in the prostatic fluid.
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***Doxycycline
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What is used for syndrome of inappropriate secretion of ADH (SIADH)?
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Demeclocycline - blocks ADH receptor function in collecting ducts)...V2 receptor.
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Where are Tets metabolized?
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Kidney for most (decrease in renal dysfxn)
Liver - doxycycline |
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Why do you not want to take Tets w/ antacids?
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They are CHELATORs - Tets bind to divalent ions (Ca, Mg, Fe, Al, and milk), which decrease their fxn.
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What SE's are assoc. w/ Tets?
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***tooth enamel dysplasia and possible decrease in bone growth (avoid in kids)
Photoxicity (demeclocycline, doxycycline) |
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What drugs are assoc. w/ phototoxicity?
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Tetracyclines
Sulfonamides Quinolones |
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What is the activity and SE's w/ chloramphenicol?
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Bacteriostatic w/ a wide spectrum of activity.
SE's - ***Gray baby syndrome in neonates (decrease in glucoronosyl transferase) - dose dependent bone marrow suppression |
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What drugs are known as macrolides (macs)?
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"-thromycins" - erythromycin, azithromycin, clarithromycin
Wide spectrum antibiotics |
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What mac is used for gram pos. cocci, atypical organisms (chlamydia, mycoplasma), legionella pneumophila, campylobacter jejuni?
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Erythromycin
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What mac is more active in respiratory infxns, including mycobacterium avium-intracellulare?
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Azithromycin
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What mac has increase activity for M. avium and H. pylori?
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Clarithromycin
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What are the pharmakokinetics of macrolides?
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-Erythro/Clarithromycin - by liver.
-inhibit cyto p450s -not safe in pregnancy -Azithromycin - excreted by kidney -does NOT inhibit p450s -safer in pregnancy |
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Macrolides stimulate motilin receptors and cause...
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GI distress (erythro,azithro > clarithromycin)
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True or False:
macrolides cause reversible deafness at high doses. |
True
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What causes cholestais, jaundice?
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erythromycin
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What is commmonly used in the treatment of CAP (comm. acquired pneumonia)?
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Macrolides
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What drug has the same MOA as macs?
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clindamycin - narrow spectrum; gram pos. cocci (not MRSA) and anaerobes, including B. fragilis
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What is the first known drug to cause psuedomembranous colitis (drug induced C. difficile)?
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***Clindamycin
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What drugs are used in the treatment of VRSA, VRE and drug resistant pneumococci?
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***Linezolid
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What agents are OK to use during pregnancy?
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PAC's -
Penicillins Azithromycin Cephalosporins |
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What are ANTIhypertensive drugs that act on the sympathetic nervous system?
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1. Clondidine and methyldopa (work centrally as alpha 2 agonists)
2.Hexamethonium 3.Reserpine (degrades storage vesicles 4. Guanethidine (inhibites NE release) 5. Prazosin (alpha 1 blocker) 6. Beta blockers |
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What agents are streptogramins that bind at the 50s subunit?
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Quinuprisin and dalfopristin
-used parenterally for severe infxns (VRSA and VRE) |
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What is the drug of choice for Nocardia?
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Trimethoprim-sulfamethaoxazole (TMP-SMX)
-used for opportunistic infxns (nocardia, pneumocystisis carinii) as well as UTI's. |
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Sulfonamides have high protein binding...think DI's with what drug?
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Warfarin
Also be aware of Kernicterus - high protein binding causes bilirubin to be displaced. |
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Hypersensitivity (rash, Steven-Johnson syndrome), photoxicity, GI distress, and hemolysis in G6PD are SE's assoc. with?
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Sulfonamides
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Bone marrow suppression is a SE with what drug?
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Trimethoprim
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What drugs inhibit topoisomerase II (DNA gyrase) and toporisomerase IV and are bactericidal?
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Quiolones (-oxacins)
norfloxacin, ciprofloxacin, ofloxacin, and other -oxacins |
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If a pt. is allergic to penicillin and a macrolide what would be your next option?
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Levofloxacin
Not used as first line for anything but a great alternative due to broad activity and clinical uses...UTI's, STD's, drug resistant pneumococci Great at killing gram neg's |
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Why would you worry about using a quinolone w/ antacids?
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They are CHELATORS....iron and calcium limit their absorption.
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Major SE's assoc w/ Quinolones (-oxacins)?
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-***Photoxicity - rash but only on sun exposed areas.
-tendonitis or tendon rupture (inhibition of chondrogenesis) -increased QT interval (torsades) |
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True or False
Quinolones (-oxacins) can be used in prego's and children? |
FALSE - contraindicated in pregnancy and children (inh. of chondrogenesis)
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The "BMT" regimen of bismuth, metronidazole, and tetracycline is used for?
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H.pylori - GI ulcers
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What drugs make up the MCAT pneumonic for treating H.pylori***?
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Metronidazole
Clarithromycin Amoxicillin Tetracycline |
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What unclassified antibiotic has strong activity against most anaerobic gram neg species (Bacteroides and Clostridium)?
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Metronidazole
"Get BaC on the METRO" BaC = Bacteroides/Clostridium DOC in psuedomembranous colitis (C.diff) |
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An unpleasant side effect with Metronidazole?
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Metallic taste
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What is the prophylactic/treatment for Mycobacterium avium intracellulare (MAC)?
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"MAC treat w/ Macrolides"
-azithromycin and clarithromycin |
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What is the combo drug therapy used for TB?
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TB - usually assoc w/ pulmonary/breathing problems.
"RESPIRE" drugs Rifampin Ethambutol Streptomycin (backup drug) Pyrazinamide Isoniazide r (blank) e (blank) |
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What TB drugs MOA is to inhibit mycolic acid synthesis?
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Isoniazid (INH)
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SE's w/ Isoniazid?
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Hepatitis
***Peripheral neuritis (tx w/ vit. B6) SLE in slow acetylators |
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Major SE's w/ Rifampin?
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***Induction of P450 (DI's)
***Red orange metabolites (your pee is orange) Hepatitis |
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SE assoc. w/ Ethambutol?
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Decrease in visual acuity - ***red/green color blindness
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SE w/ Pyrazinamide?
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***hyperuricemia
hepatitis |
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SE w/ streptomcyin?
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Nephrotoxicity/Ototoxicity
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What type of agent interacts w/ ergosterol to form artificial "pores" which disrupt membrane permeability?
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Amphotericin B - wide fungicidal spectrum. DOC for severe infxns by Aspergillus, Candida, Cryptococcus***, Histoplasma,Mucor, and Sporothorix
Nystatin - used topically for localized infxns. |
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What agents SE's are infusion related and have fever, chills, muscle rigor, hypotension (histamine release)?
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Amphotericin B - can be partly relieved w/ pretreatment by NSAIDS, antihistamines.
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What amphoteric compound has dose dependent nephrotoxicity?
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amphotericin B
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What antifungal agents are fungiCIDAL and interfere w/ the synthesis of ergesterol?
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"Azoles" - Ketoconazole, ***Fluconazole, Itraconazole
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What is the only 'azole' to penetrate into the CNS?***
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Fluconazole - useful for crytptococcal meningitis
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What antifungal agents decreases synthesis of steroids; decreasing libido, gynocomastia, menstrual irregularities?
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Azoles - fluconazole, ketoconazole, itraconazole
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What anitfungal agent is used in combo w/ amphotericin B and is toxic to bone marrow?
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Flucytosine (5-FU)
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What antifungal agent is active only against dermatophytes and works by disrupting microtubule structure?
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Griseofulvin
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What agents are microtubule inhibitors?
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Griseofulvin
Colchicine Vinicristine Vinblastine Paclitaxel |
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What drug is active only against dermatophytes and DOC for onchomycoses?
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Terbinafine
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What drugs MOA is monophosphorylated by viral thymidine kinase, and further bioactivated host-cell kinases?
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Acyclovir - when incorporated into the DNA molecule, acts as a chain terminator
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Clinical uses are herpes simplex virus (HSV) and varicella-zoster virus?
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Acyclovir - topical, oral, IV forms
-reduces viral shedding in genital herpes |
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Name to newer drugs approved for HSV infxn and are similar to acyclovir in MOA?
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famciclovir and valacyclovir - have longer t1/2 than acyclovir
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SE's w/ acyclovir?
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-crystalluria (maintain hydration)
-neurotoxicity (agitation, headache - seizures in OD) |
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What agent is similar to acyclovir in MOA and main clinical use is against CMV?
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Ganciclovir
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SE's w/ ganciclovir?
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dose limiting hepatotoxicity (leukopenia, thrombocytopenia)
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What agent inhibits viral DNA and RNA polymerases and has greater activity against acyclovir-resistant strains of HSV?
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Foscarnet
SE - dose limiting hepatotoxicity |
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What agents are components of most combination drug regimens used in HIV infxn, used together w/ a PI (protease inhibitor), and highly active antiretroviral therapy (HAART)has often resulted in decreased viral RNA?
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Nucleoside reverse transcriptase inhibitors (NRTIs)
Zidovudine - prototype Azidothymidin (AZT,ZDV) |
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What are RTI's that do not require metabolic activation?
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Nonnucleoside reverse transcriptase inhibitors (NNRTI's)
nevirapine efavirenz |
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What DI's increase levels of Zidovudine?
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cimetidine***
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What DI's decrease levels of zidovudine?
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Rifampin***
-watch out for concurrent TB/HIV infxn |
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Hepatotoxicity*** is a major SE of what NRTI?
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Zidovudine (AZT)
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Pacreatitis*** is a major SE of what NRTI?
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Didanosine (DDI)
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What is the least toxic*** NRTI?
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Lamivudine (3TC)
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What NRTI combo's do you want to avoid?
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DDI (Didanosine) + DDC (Zalcitabine) b/c of additive toxicity
D4T (Stavudine)+ AZT (Ziduvodine) b/c of competition for activation |
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What antivirals target is protein M2 on influenza A virus?
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Amantidine, Rimantdine
prophylaxis mainly - used to decrease duration of flu symptoms |
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What agent inhibits neuramindases of influenza A and B?
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Oseltamivir (Tami flu)
-blocks shedding release of virus -used to decrease sx's of flu -SE's - N/V |
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Needlestick HIV prophylaxis?
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ZDV + 3TC (zidovudine + Lamuvidine)
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Pregnancy HIV prophylaxis?
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ZDV full dose, 2nd and 3rd trimesters plus 6 wks to neonate
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DOC for amebiasis?
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Metronidazole
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DOC for Giardiasis?
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Metronidazole
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DOC for Trichomoniasis?
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Metronidazole
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DOC for Pneumocystosis?
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TMP-SMX
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DOC for Toxoplasmosis?
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Pyrimethamine + sulfadiazone
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DOC for Leishmaniasis?
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Stibogluconate
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DOC for Trypanosomiasis?
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Nifurtimox (Chagas dz)
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What is the agent used for Malaria?
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Chloroquine
P.falciparum - Chloroquine P.malariae - Chloroquine P.vivax - Chloroquine + primaquine P.ovale - Chloroquine + primaquine |
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Adverse effects of antimalarial drugs?
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"-quine" drugs =
Chloroquine, Hydroxychloroquine, Mefloquine, Primaquine, Quinine SE's - GI distress |
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DOC for nematodes (worms)?
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Mebendazole or Pyrantel pamoate
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DOC for cestodes (tapeworms) amd trematodes (flukes)?
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Praziquantel
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