micro drugs

Question 1

Penicillin

Answer 1

bind penicillin binding proteins and block transpeptidase cross liking
used for gram +
-N meningitid
-treponma
bactericidal
resistance via penicillinase in bacteria cleaves Beta lactam ring

Question 2

amox/ampicillin

Answer 2

bind penicillin binding proteins and block transpeptidase cross linking 
used for gram +
-n meningit 
-treponema 
-h influenza
-h pylori 
-e coli
-listeria 
-proteus 
-salmonella 
-shigella 
-enterococci
toxicity: hypersensitivity rash, c diff 
resistance via penicillinase in bacteria that cleaves beta lactam ring

Question 3

dicloxacillin/nafcillin/oxacillin

Answer 3

penicillinase resistant penicliins
-bind penicillin binding proteins and preent transpeptidase cross linking
-bulky R group blocks penicillinase
S aureus (except MRSA)
tox: hypersensitivity, interstitial nephritis

Question 4

piperacillin/ticarcillin

Answer 4

antipseudomonals
bind penicillin bidnign proteins and prevents transpeptidyase cross linking
used for pseudomonas, gram - rods
***sensitive to penicillinase so use with b lactamase inhibitor
-tazobactam, clavulanic acid, sulbactam

Question 5

cephalosporins

Answer 5

inhibit cell wall synthesis but less sensitive to pencicillinases
-bactericidal
not convered by cephalosporins LAME
-listeria, atypicals (chlamydia mycoplasma), MRSA, enterococci
resistance via structural changes of penicillin binding proteins

Question 6

cefazolin cephalexin

Answer 6

first generation cephalosporins
used for gram + cocci
-proteus ecoli klebsiella

Question 7

cefoxitin cefuroxime cefaclor

Answer 7

2nd generation cephalosporins
gram +
h flu, enterobacter, neisseria, proteus, e coli, klebsiella, serratia

Question 8

ceftriaxone cefotaxime ceftazidime

Answer 8

3rd generation cephalosporins for serious gram - infections

ceftriax: meningitis, gonorrhea, disseminated Lyme
ceftazidime: psuedomonas

Question 9

cefepime

Answer 9

4th generation cephalosproin
gram -
pseudomonas

Question 10

ceftaroline

Answer 10

5th generation cephalosporin
-broad gram + and gram - organism coverage including MRSA
NO pseudomonal

Question 11

cephalosporin side effecets

Answer 11

hypersensitivity
autoimmune hemotylic anemia
vit k def
increase nephrotoxcity of aminoglycosids

Question 12

imipenem meropenem ertapenem doripenam

Answer 12

betalactamase resistsant, prevents cell wall synthesis
always given with cilastatin to decrease inactivation of drug in the renal tubules
-used for gram + cocci
gram - rods
anaerobes
side effects limit use: Gi distress, skin rash, seizures at high plasma levels

Question 13

aztreonam

Answer 13

monobactam
less susceptible to beta lacaases
binds to penicillin binding proteins and prevents peptidoglycan cross linking
-used for gram - rods only
-esp for patietns with penicillin allergy and renal disease who cannot handle aminoglycosides

Question 14

vancomycin

Answer 14

binds D-ala D ala portion of cell wall precurosors and inhibits cell wall peptidoglycan formation
-Gram +
serious multidrug resistant bacteria: MRSA, S epi, enterococcus, c diff (oral)
toxicity: nephrotoxic, ototoxic, thrombophlebitis
red man syndrome: diffuse flusing-slow infusion and pre-treatment with antihistamines can prevent this from occuring
resistance via: D ala D ala to D ala D lac

Question 15

gentamicin neomycin amikacin tobramycin streptomycin

Answer 15

aminoglycosides
inhibit 30s ribosomal subunit, irreversible inhibt protein synthesis, bacteriocidal
ineffective against anaerobes-require O2 (fusobacterium clostridium actinomyces bacteroides)
used for severe gram - rod infections
synergistic with beta lactam antibiotics
tox: nephro, oto, neuromusclar blockade, teratogen
resistance: bacterial transferase enzymes inactivate via acetylation/phosphorylation/adenylation

Question 16

tetracycline, doxycycline, minocycline

Answer 16

bind 30s and prevent attachment of aminoacyn tRNA
-bacteriostatic
-minimal CNS penetration
used for borrelia, m pneumonia, rickettsia, chlamydia acne
toxicity: GI distress, teeth discoloration, inhibit bone growth in kids, photosensitivity
contraindicated in pregnancy
resistance: decreased bacterial intake or increased efflux by plasmid encoded transport pumps

Question 17

chloramphenical

Answer 17

blocks peptidyl transferase at 50s ribosomal subunit, bacteriostatic
used for: meningitis-h influ, neissueria, strep pneu and RMSF
toxicity (high but used in developing countries bc cheap)
-anemai, aplastic anemia, grey baby syndrome
resistance via plasmid encoded acetyltransferase that inactivates the drug

Question 18

clindamycin

Answer 18

blocks peptidyl transfer at 50S ribosomal subunit
-bacteriostatic
-used for anaerobic infections (bacteroides, clostridium, actinomyces, fusobactreium)
also GAS
toxicity: pseudomembranous colitis, fever, diarrhea

Question 19

linezolid

Answer 19

inhibits protein synthesis by binding to 50s ribosomal subunit

• used for gram + MRSA, VRE
• tox-bone marrow suppreession (thrombocytopenia), peripheral neuropathy, serotonin syndrome
  resistance: point mutation of ribosomal RNA

Question 20

azithromycin, clarithromycin, arythromycin

Answer 20

macrolides
-bind 23s rRNA of 50s ribosomal subunit
used for aypical pneumonias: mycoplasma, legionella, chlamydia, STI-chlamydia, gram + cocci, b pertussis
toxicity: MACRO
-gi Motility, Arrythmia prolonged QT, Cholestatic hepatitis, Rash, eOsinophilia
increase serum concentration of theophyllines and oral anticoagulants-inhibit cyp p450
resistance via methylation of 23srRNA subunit

Question 21

trimethoprim

Answer 21

inhibits dihydrofolate reductase
bacteriostatic
-used in combination with sulfamides
UTIs, shigella, salmonella, pneumocystis jirovecii tx and ppx , toxo ppx
toxicity: megaloblastic anemia, leukopenia, granulocytopenia

Question 22

sulfonamides

Answer 22

sulfamethozazole, sulfaisoxazole, sulfadiazine
-inhibit folate syntheis
bacteriostatic-cidal when combined with trimethoprim
gram +. - nocardia/chlamydia
hypersensitivyt, hemolysis if G6PD def, nephrotoxic, photosensitivity, kernictuers in baby, displace other drugs from albumin (ie warfarin)
resistance: altered enzyme or decrease uptake/increased effluz, increase PABA synthesis

Question 23

ciprofloxacin, norfloxacin, levofloxacin, ofloxacin, moxiflocain, gemifloxacin, enoxacin

Answer 23

inhibit prokaryotic enzymes: topoisomerase (DNA gyrase)
-bactericidal, cannot be taken with antacids
gram - rods in urinary and Gi tract including pseudomonas, neisseria, and some gram +
toxicity: GI upset, superinfection, skin rash, headache, dizziness, leg cramps, myalgias, contraindicated in pregnant women, nursing mothers, and children <18
QT prolongation
resistance: chromosome encoded mutation in DNA gyrase
plasmid mediated resistance, efflux pumps

Question 24

daptomycin

Answer 24

lipopeptide that disrupts cell membrane of gram positive cocci

• used for s auerus skin infections (esp MRSA), bacteremia, endocarditis, VRE *not pneumonia, binds to and is inactivated by surfactant
  toxicity: myopathy, rhabdomyolysis

Question 25

metronidazole

Answer 25

forms toxic free radical metabolites in the bactrerial cell taht damage DNA
-bactericidal, antiprotozoal
used for: giardia, entamoeba, trichomonas, gardernella, anaerobes, with PPI for triple therapy
toxicityL disulfiram like reation (tachy, flusing, hypotension) wtih alcohol, headache, metallic taste