Antibiotics 2 Flashcards

Terms Definitions
borellial infection
Mycostatin (antifungal)
erythromycin ethylsuccinate/sulfisoxazole
Minocin (tetracycline)
ARFProlonged QTHemolysisHyperkalemia
Macrolide, mostly outpatient.Bacteriostatic.Good for gram +ves, aerobes, GAS, pneumococcii, bordetella pertussis, campy, leigonella, mycoplasmas.May cause GI upset.
clostridium colitis
metronidazoleORvancomycinoral admin
aminopenicillins (2)
fortovase (protease inhibitor)
Dynapen (penicillinase-resistant penicillin)
penicillin V potassium
Metronidazole for...
Anaerobes, parasites
Indanyl Carbenacillin
specific purpose anti-pseudomonas
better oral absorption
pancytopenia SE-what drugneurotoxicity what viral drug?
topical use from trachoma
Polyene drugs
Amp B, nystatin
DOC for campylobacter jejuni

-generic and QD dosing
-longest t1/2 of all ceph's
-covers wimpy G+ anaerobes but not DOC
Tetracyclines, gm+, gm-, acne
ADE Chloramphenicol
-Gray baby syndrome
organism that causes AIDs
Abd painheadachereversible hearing lossNVTinnitus
If an organism produces beta-lactamases, what will it be resistant to?
Gram + anaerobes
-clostridia-streptococcus-related gram positive cocci (SRGPC)
specific purpsoe antipseudmonas and proteus
MORE active against klebsiella
What drug causes arthralgia-myalgia and phelbitis?
gentamicin spectrum
Aerobic gram negative rods.
sulfonamide + pyrimethaminesame as plasmodium (apicomplexan, similar organism)
Examples of Anti-pseudomonas PCNs?
ticarcillin, piperacillin
what doesn't work against leprosy
ticarcillin + clavulanic acid

not good for ___

True/False. Ribavirin is excreted primarily by the kidneys, with some excreted in stool.
T/F Second Generation Cephalosporin act against Gram – bacteria but better than first generation.
Cephalosporins-1st gen, gm+, little gm-, no H. flu, no B. fragilis
Escherichia coli category
Enteric gram-negative Bacilli
Drug of choice for Listeria?
Tetracyclines-therapeutic use
Benign Intracranial HtnLupus-like syndrome- minocyclineFirst tri facial abnormalities
permethen lotion
scabicidal agent
adverse effects: Itching, tingling, numbness, redness or irritation
Teratogenic Effects
contraindicated in patients with known hypersensitivity to any of its components
excreted in urine
Which antimycobacterial Rx causes an orange discoloration of urine?
gram - aerobes, cocci
Neisseria Sp.moraxella catarrhalis
Penicillins and Cephalosporins
Mechanism: covalently bind PBPs
Toxicities: Rash to anaphylaxis, nephrotoxicity, bleeding
Resistance: Beta lactam ring
Kinetics: Short half life, renal elimination of organic acids, hepatic lysis of lactam ring
Stable to penicillinase.Good for MSSA, gram -ves. Is quite expensive.Adjust dose in renal failure.
inhibit bacterial gyrase (Topo-II) and Topo-IV
man-made --> low resistance
highly bacteriocidal, broad spectrum, low MIC
concentrated in urine during excretion
block cell wall synthesis by inhibiting peptidoglycan cross linking
Broad Spectrum antimicrobials
Penicillins- Amoxi, Ampicillin, ClavamoxCephlalosporinsTetracyclinesChloramphenicol/ FlorfenicolSulfonamidesFluoroquinolones
Enterococcus Faecium is most often seen clinically as ___?
Inhibits viral DNA and RNA polymerases. Use for HSV, VZV, CMV, AIDS retinitis, transplant patients. Side effects: nephrotoxic acute tubular necrosis, hypocalcemia (tremors, seizures)
DOC for enterococcal endocarditis
Ampicillin + gentamicin
penicillin-induced prolonged bleeding time most likely with ___ and ___
ticarcillin and carbenicillin
T/F Fourth Generation Cephalosporin is Usually placed “in reserve” for multi-resistant nosocomial strains causing infections.
True/False. Aminoglycosides have poor oral absorption and have no PO forms.
Procain pen G
Natural penicillin, gm+ anaerobes
Host Factors for Antimicrobials [10]
-Where acquired
-Previous exposure to abx
-Previous cultures
-Recent environment exposure
-Drug allergy
-Renal/Hepatic Dysfx
-Concomitant therapy and comorbidities
drug usually used to treat MAC
Therapeutic ratioRatio of toxic human dose to therapeutic doseHigher is better (really)
1st generation cephazolin given parenterally
others orally
What is recommended to treat VRE?
Betalactamase Inhibitors
What type of antibiotics inhibit plasmid-mediated rather than chromasomally-mediated enzymes?
Staph aureus
Betalactamases makes what resistant to penicillins?
Kirby-Bauer Disk Diffusion, Tetracycline values
Resistant= = 14mmIntermediate= 15-18mmSusceptible= >/= 19mmDisk Potency 30mcg of TCN
what are common ae of penicillins
diarrhoea, nausea
What drug falls in the lincomycin class?
azithromycin mechanism of action
inhibits 50s ribosomal subunit
clinical uses of Metronidazole
trichomonal infections, amebiasis, Giardiasis, Clostridium difficile, anaerobic bacterial infections (bacteriodes)H. pylori (with other drugs), rosacea (topical gel)
Name the major groups of B-lactam antibiotics
Mechanism of resistance to penicillin
Beta-lactamases (staphylococci); structural change in PBPs (MRSA); change in porin structure (pseudomonas)
Zidovudine (ZDV, AZT)
Converted to triphosphate that inhibits reverse transcriptase and causes chain termination. Resistance by mutations of RT gene.
AG combo to tx Listeria
amp + gent
Q/D coverage
Gram + (NO negs)
E. faecium->NOT faecalis
meningitis tx

but also FQ's
cover H. flu, N. menigitidis, and some gram neg. rods
sulfonamide distribution
-pass into ALL body fluids/tissues
What are the Penicillinase-resistant penicillins (narrow-spectrum)?
1-dicloxacillin, 2-nafcillin, 3-oxacillin, 4-cloxacillin, 5-methicillin
Active against penicillin resistant S. pneumoniae?
-Macrolides (-thromycins)
antifungal drug administered by "swish & swallow" method; for what infection?
nystatin; thrush
1st gen cephs good vs.
staph and strep
Name 4 bacteriostatic protein synthesis inhibitors:
Tetracyclines, clindamycin, macrolides, linezolid.
What does Quinopristin/dalfopristin affect?
combination is synergistic, affecting both the early (dalfopristin) and late (quinupristin) stages of proteins synthesis
Azithromycin has superior activity versus what?
Mycoplasma, Chlamydia, H. influenzae
Penicillin G
What is the most active antibiotic against most strep?
selective toxicity
going after cell walls w/o affecting human cells
periplasmic space
gram (-), beta lactamase hang out here-antibiotic comes into pourin channel to where high conc. of b. lactamase is
What is the leading cause of C. Diff/dose?
How is Vancomycin eliminated from the body?
renal excretion
Antimicrobials that affect primarily Gram Positives (G+)
PenicillinsCephalosporins (esp. early generations)BacitracinMacrolidesLincosamidesRifamycinNovobiocin
Uses of quinolones
UTIs resistant to cotrimoxazole, PID (chlamydia, gonococcus), skin and bone infections by gram-, diarrhea to shigella, salmonella, E. coli, campylobacter
MOA of penicillins
Bind PBPs to inhibit transpeptidation reactions in peptidoglycan cross-linking --> inhibit cell wall synthesis
S.E. of clindamycin
hypotension and cardio collapse when IV infused too fast

Antibiotic associated Psuedomembranous colitis(AAPC)

amoxicillin + clavulanic acid
**the only PO product
vancomycin MOA
recognizes and sits on D-Ala-D-Ala so that the "brick" can't fit into cell wall acceptor molecule
What Bacteria causes Lyme Disease that is treated with Tetracyclines?
Borrelia Burgdoferi
Vancomycin works against? (4 important)
-C. difficile (oral only)
-Ampicillin resistant enterococcus (VSE)
-Coagulase-negative Staphylcoccus (CoNS)
What is an increased risk when giving IV cephalosporins?
Used to treat pneumocystocarini in HIV
Sulfamethoxazol + Trimethoprim
What is telithromycin used for?
developed specifically for treatment of community-acquired respiratory tract infections caused by both common and atypical pathogens, including resistant strains
What test is used to confirm group B streptococci?
First line drug for a pt who has VRE?
Gram + characteristic
-prod. exotoxins, just leak out b/c pourous-peptidoglycan lattice work of protein and complex sugars..very pourous-much more peptidoglycan than gram -
What drug are 40% of the people in buffalo that have staph resistant to?
SE for this drugs are Kernicterus in newborn
Septra DS
What are the major toxicities of TMP/SMZ combo therapy? In which populations are these effects seen?

(aside from the three (jaundice, hematopoe dz, hyperS) seen in single SMZ tx as well)
Megaloblastosis, leukopenia, thrombocytopenia in those with folic acid deficiency (alcoholics, homeless, malnourished)

Rash, fever, & hepatitis in AIDs pts tx'ed for PCP.
MOA and resistance to rifampin
Inhibits DNA-dependant RNA polymerase; resistance via change in enzyme
clarithromycin is used for what infection in AIDS pt
MAC infections-multidrug regimen (+rifabutin + ethambutol)
1st gen ceph's adverse effects

-Bleeding (worst with moxalactam - discontinuted)
-Biliary sludging (ceftriaxone only)
-Kernicterus (ceftriaxone & sulfonamides)
-hyperSENSITIVITY reactions
-DISulfuram-like reaction with EtOH
What are the four groups of Penicillins?
1-Natural, 2-Penicillinase-resistant penicillins (narrow spectrum), 3-Aminopenicillins (Wide Spectrum), 4-Extended Spectrum (antipseudomonal) penicillin.
S &S of infection
Pain, erythema, loss of function, swelling, heat, fever, drainage
quin effective vs. infections
bone, joint, soft tissue
- chronc osteomyelitis
--- resistance in s. aureus, p. areugeneusa and s marc.
Tetracyclines are the DOC for anthrax (B. anthracis) - how are they used?
treatment of inhalational anthrax
treatment of cutaneous anthrax
What drug would you give for a pt who is allergic to penicillins and has an early animal bite?
1) enzymatic inactivation or modification of drug
-b. lactamase hydrolysis of b.lactam ring-modification of aminoglycosides by acetylating, adenylating, or phosphorolating enzymes -causes it to look completely different -can't get through the cell wall, or if it does, the affinity for ribosomes is gone and no longer interacts
What tpe of resistance is found with cephalosporins?
plasma mediated B-lactamase
this 3 drugs cause hemolytic anemia in G6PD pt.
DAP(dapsone), isoniazide, nitrofurantoin
How is drug resistance perpetuated? (3)
Mutation and selection

Uptake of extracellular DNA and homologous recombination (Haemophilus, Neisseria, Streptococcus)

Plasmid-mediated transfer of R-factors (plasmids containing up to 5 different resistance genes)
AA Psuedomembranous colitis in clindamycin...gen info
clindamycin #1 cause-#2 is ampicilin, #3 cephs

due to cytotoxin by clindamycin resist. C diff

avoid opoids-may worsen constipation
4th gen ceph coverage
-CEFEPIME = the only 4th gen ceph
-excellent G- coverage
-good G+ coverage
-used when 3rd gen ceph's don't work
-NOT good for anaerobes (B.frag)
-use for bugs that display MDR (multidrug resistance)
What are the side effects of Quinolones in the CNS?
headache, dizziness, fatigue, depression, restlessness
What are the two classifications of Antimicrobial Drugs
Narrow & broad spectrum
What is usually assocatied with nephrotoxicity of AGs?
elevated trough serum levels of AGs
t1/2: 30 minutes
only 1/3 of oral Penicillin G absorbed via GI tract
GRAM + cocci (staph, strep, bacilli)
except penicillinase producing S. aureus
Gram + bacilli
Gram - cocci (neisseria spp)
oral on empty stomach
What effect do penicillinases have on Cephalosporins?
Cephalosporins are resistant to Beta-Lactamases
Bacteroids fragilis is most often seen clinically as ___?
septic abortion, aspiration pneumonia, pelvic abscess
sequence of stage 3 of bacterial cell wall synthesis
1. transpeptidase directs cross-linking of free NH2 of terminal Gly in one chain to the next-to-last D-Ala in nearby side chain
2. terminal D-Ala is kicked out during the cross-linking process
3. 3-D cross-linked structure is very stable
What are the ADR of Rimantadine?
less CNS toxicity than Amantadine (ataxia, dizziness, insomnia – more seriously, hallucinations and seizures)
What type of infections are treated w/ Vanco
Staph, psuedomembranous colitis, MRSA
What is erythromycin's active form (base) inactivated by?
inactivated by acid, so use delayed release (enteric coated) tablets
T or F sulfonamides are bacteriocidal
False- they are bacteriostatic after a delay
63. A 75-year-old woman is hospitalized for pneumonia and treated withan intravenous antibiotic. On day three, she develops severe diarrhea. Stoolis positive for Clostridium difficile toxin. What is the best treatment?a. Clindamycinb. Cefaclorc. Metronida
The answer is c. (Hardman, pp 996–997, 1145–1146. Katzung, p 845.)Metronidazole is often used to treat antibiotic-associated enterocolitis,especially when caused by C. difficile. Vancomycin is no longer preferredbecause it induces selection of resistant staphylococci. Clindamycin is alsoassociated with C. difficile colitis, but in another way: a higher percentage ofpatients taking this over other antibiotics develop antibiotic-associatedenterocoliti
how to reverse problem of pt on AG's and given NMJ blockers for surgery
give IV calcium gluconate
What is the Mechanism of Action of Ribavirin?
guanosine analog that converts ribavirin – triphosphate which purportedly inhibits viral mRNA synthesis
isosoxazil pen absorption and fate of drugs - excretion similar to pen G and Pen V
similar to pen V and G
AGs are the DOC for treatment of endocarditis caused by what two bacteria?
E. faecalis and non-VRE E. faecium
What two drugs are often given for necrotizing faciitiis and why?
clindamycin because it can prevent toxin prduction
PNC b/c 15% of Group A strep is resistant to clinda
What major side effect has been reported for metronidazole?
Neurotoxicosis which may recover in 1 to 2 weeks
Which of the following is not a penicillin beta-lactamase inhibitor combination drug? 1- Augmentin, 2-Bactrim, 3-Timentin, 4-Zosyn, 5-Unasyn, 6-Pedizole.
6-Pediazole is not a beta-lactamase inhibitor, it is a sulfonamide (sulfisoxazole)
Dosing ratio of sulfamethoxazol and Trimethoprim?
5/1 which results in plasma ratio of 20/1 which is optimal for therapy bc larger Vd for trimethoprim (9-fold) and higher degree of plasma protein binding for sulf. 90 vs 50%
94. A 40-year-old female with duodenal ulcers is treated with a combinationof agents that includes clarithromycin. Of the following enzymes,which is inactivated by clarithromycin?a. Dihydrofolate reductaseb. Glucose-6-phosphate dehydrogenasec. Cytochrome
94. The answer is c. (Katzung, pp 778–780.) Clarithromycin is amacrolide antibiotic. It can inhibit cytochrome P450. This could lead toan increase in concentration of drugs that are metabolized by cytochromeP450 and are given simultaneously with clarithromycin. When given withterfenadine, an antihistaminic agent, the interaction may lead to cardiacarrhythmias.
How does Tetracyclines form insoluble complexes?
It binds to Ca2+ and Mg2+ and Al3+ ions
54. The most effective agent in the treatment of Rickettsia, Mycoplasma,and Chlamydia infections isa. Penicillin Gb. Tetracyclinec. Vancomycind. Gentamicine. Bacitracin
The answer is b. (Hardman, p 1128.) Tetracycline is one of the drugsof choice in the treatment of Rickettsia, Mycoplasma, and Chlamydia infections.The antibiotics that act by inhibiting cell-wall synthesis have noeffect on Mycoplasma because the organism does not possess a cell wall;penicillin G, vancomycin, and bacitracin will be ineffective. Gentamicinhas little or no antimicrobial activity with these organisms.
What is the major use of aminoglycosides?
major use for over 30 yrs of AG is g-aerobic bacilli
Anti pseudomonas
Streptogramin drugs
Zovirax (antiviral)
Penicillin G
Levaquin (quinolone)
gram -, microaerophilic
Wuchereria bancrofti (filariae)
nalidixic spectrum

suspected carcinogen
Antipseudomonal Penicillin, pseudomonas
Active against Atypicals
50 S subunit
Aplastic anemiaoptic neuritis
Host Defenses
-Skin-Respiratory Tract-GI tract-Genitourinary Tract-Blood
1st generation cephalosporin.Oral.Ok for MSSA, GAS, gram -ves (UTIs).
Imipenem, meropenem, ertapenembroadest spectrum (gram+/-); resistant to B-lactamases; TOXIC
Name some aminoglycoside antibiotics.
Clindamycin aka
inhibits A window->peptidyltransferase on 50S
how is clindamycin eliminated
penicillin-induced seizures
most likely penG
Mycobacterium category
Acid-Fast Bacilli (AFB)
Protein Synthesis (30s) Abx
ability to kill bacteria
contraindicated with crusted scabies and seizures
not studied in pregnancy, present in breast milk
adverse effects: dry skin
facultative anaerobes
-aerobic-oxygen is electron acceptor-positive for catalase and peroxidase (2 of 3 enzymes)-can grow in the absence of oxygen through fermentation derived energy-prefer oxygen but have the "faculty" to grow in anaerobic conditions
Antistaphylococcal.Not good for MRSA, gram -ves.Good for GAS, MSSA.Poorly absorbed orally.
What are the three macrolides?
to treat topical dermatophytic infection two drugs could be used.
Define MIC
MIC (Minimum inhibitory concentration)- lowest concentration of the drug that inhibits growth after 18-24 hrs of incubation in vitro
Blocks attachment, penetrationa and uncoating of Influenza A. May decrease flu symptoms. Side effects: nervousness, insomnia, atropine-like effects
Tigecycline kinetics
No CYP effects
2nd gen FQ drugs

systemic-ofloxacin, ciprofloxacin
T/F: aminopenicillins are resistant against B-lactamase
True/False. Can Penicillins activate autolytic enzymes?
T/F Third Generation Cephalosporin Ceftazidime is given IV and IM, has excellent Gram – coverage and is used for difficult to treat organisms such as Pseudomonas and is eliminated by renal instead of biliary route and has excellent spectrum of coverage.
Aminoglycosides, powerful gm-, low resistance
Ciprofloxacin (anti infective)
Cipro (anti infective)
infectious disease caused by fungi
1st gen cephs
cephazolin, cephalexin, cephadoxil
Name two glycopeptides:
Vancomycin & daptomycin
What drugs classically increase GI motility?
Klebsiella-enterobacter serratia group
-enteric bacilli-gram - rods-enterobacter cloacae-seratia marcescens
What antibiotics are active against poolymyxin B and E; they act by disrupting bacterial membrane
Macrolide, out patient.Good for Hib, shigella, GU bugs.High tissue levels.Concentrated in PMN leukocytes and macrophages.Easy dosing.
Carbapenem drug
Meropenem, a beta lactam antibiotic
block cell wall synthesis by inhibiting peptidoglycan cross linking
plasmodium falciparum
sulfadioxone + pyrimethaminesame as toxo
AG's with vestibular problems
streptomycin, gentamicin, tobramycin
Chloramphenicol MOA
binds to A window->inhib peptidyltransferase 50S->can't make proteins

inhibits protein synt. only when 70S present
penicillins DO NOT distribute well into...(5)
sulfonamide crystalluria
-rare with modern sulfa drugs
-hematuria is common early sign
What is Cefepime?
4th gen cephalosporin (Maxipime)-newest
True/False. Rimantadine does not cross the BBB.
Cephalosporins-2nd gen, same gm+ as 1st gen, addit gm- (H. flu)
Gram Positive Organisms [3]
-Staphylcoccus aureus
-Enterococcus sp
-Streptococcus pneumoniae
Cephalosporins (cell wall synthesis) - Cephalexin (1st)
*Translation inhibitors*Tetracyclines, macrolides (erythromycin, clindamycin), Zyvox
*Nucleic acid synthesis inhibitors*Quinolones (DNA gyrase) Rifampin (RNA polymerase)
3rd gen ceph
ceftaxime ceftriaxone, cefoperazone, cefpodoxime
Adverse effects of foscarnet:
nephrotoxicity, electrolyte abnormalities
What type of abx toxicity causes ototoxicity and nephrotoxicity?
Coagulase test
only for staph-distinguish b/n s. aureus and other staph organisms-s. aureus is the only coagulase organism out of staph organisms
Neisseria meningiditis and sepsis
-coagulopathy destroys major organs-adrenal gland destruction: waterhouse-frederickson syndrome
doxycyclin is what type of antiobiotiuc, static or cidal?
static, tetracycline
What is CA-MRSA often mistaken for?
spider bite
SE: red and green color blindness
Ethambutol (ETH)
Gram stain of Clostridium perfringens?
Gram (+) rod
Pharmacokinetics of chloranphenicol
Orally effective, enters CNS, metabolized by hepatic glucoronidation, inhibits P450
Side effects of sulfonamides
Hypersensitivity, Steven Johnson, phototoxicity, GI distress, hemolysis in G6PDH deficiency
Uses of itraconazole
DOC in blastomycoses and sporotrichoses
prophylaxis of disseminated MAC in HIV pt's
red-orange fluids
less induction than rifampin
DOC for Salmonella
FQ(ciprofloxacin in 3rd world countries)->salmonella typhi
also ceftriaxone
bacitracin MOA
inhibits cell wall formation by preventing recycling of phospholipid carrier --> inhibition of Pi cleavage
What are the Extended-Spectrum Penicillins?
1-carbenicillin, 2-ticarcillin, 3-piperacillin, 4-mezlocillin
SMX-TMP spectrum
gm+ and gm- aerobes, chlamydia, protozoa, *UTIs, PCP*
Adjust dose for renal dysfunction for quinolones EXCEPT?
Pennicillin (cell wall synthesis) - Amoxicillin
base is a 7 - aminocephalosporanic acid . r group determines spectrum and pharm prop
What is the most widely used Azole?
What are tetracyclines spectrum of activity?
broad spectrum bacteriostatic
streptococcal and staphylococcal organisms
What organisms produce beta-lactamase inhibitors?
E. Coli
the most abundant organism found in normal flora followed by klebsiella species, proteus species, and enterobacter sp
what part of bacteria do polymyxins and amphotercins attack?
cell membrane
True/False: Vancomycin should be used for first line treatment in methicillin sensitive bacteria?
False, use Nafcillin
doxycycline structure
Comprised of four cyclic rings with four modification sites, ripe for modification to make new drugs.
What major class of microbes is not covered by the spectrum of the fluoroquinolones?
Side effects of quinolones
GI distress, phototoxicity, rashes, tendonitis, increases QT interval, contraindicated in pregnancy and children
which FQ has a high risk of rash
Isoniazid absorp/ distrib/ elim
oral->NOT with food
all body fluids, caseous material, CNS

m->N-acetylation then hydrolysis->inactive
which antibiotics have biliary excretion component

hint: 3 classes of B-lactamase antibiotics
-COND: cloxacillin, oxacillin, nafcillin, dicloxacillin
-PM CAT (anti-pseudomonal): piperacillin, mezlocillin, carbenicillin, azlocillin, ticarcillin
What is the mechanism of action of Aztreonam?
some drugs used to treat leprosy
Dapsone & lamprene
What antibiotic is the last drug of choice in the U.S. because of its toxic effects on bone marrow?
Adverse effects of INH:
hepatitis, peripheral neuropathy (give with Vit B6)
Either azithromycin (A) or erythromycin (E) is the DOC for...
-pneumonia caused by Chlamydia, Mycoplasma, or Legionella (A)
-whooping cough (Bordatella pertussis, E)
-diptheriae (C. diptheriae; E + antitoxin)
-PID due to C. trachomatis (A); cephalosporin or flouroquinolone for gonoccocal coverage
Clindamycin + cefoxitin
What drug combination would you use for a pt with gas gangrene with a PCN allergy?
enterococcus and resistance
-one of the most highly resistant organisms today -synergistic combinations are losing effectiveness -vancomycin resistant enterococcus (VRE) -enterococcus faecium -some evidence that the resistance factors can be passed on to more virulent organisms (staph aureus) -this is the reason we try to limit our use of vancomycin, why we closely follow resistant patterns and why we try to implement infection control
how does Vancomycin inhibit bacteria
by inhibiting cell wall synthesis
What two drugs other than PNC G is Staph Aureus 95% resistant to?
this drug is given in intrathecally as it doesn cross BBB but it is important to tx fungal meningitis.
Amphotericin B
Gram stain of Pseudomonas aeroginosa?
Gram (-) rod, non-lactose fermenter
Fourth generation cephalosporins
Cefepime (IV). Enter CNS, resistant to betalactamases
Fluoroquinolones (FQ) MOA
binds to the A-subunit of DNA gyrase(replic. + transc.) irrev. inhibiting it-> prevents resealing of DNA strands
anti-pseudomonal penicillins used for
-mainly serious, nosocomial G- bacilli infections
What is the mechanism of action for the cephalosporins?
Bactericidal action
Enterococcus faecium
-gram +
-High incidence in KUH due to bone marrow transplant population
S & S of suprainfection?
diarrhea, black furry tongue, vaginal/anal itching, candida
What can result if vancomycin given with aminoglycoside?
Cytotoxicityneutropenia, ototoxicity, nephroxicity
Tetracyclines can cause temporary cessation of bone growth or bone deformity so what does this mean?
contraindicated in pregnant or nursing women or in children < 9 years
Neutrophilia and the "Left Shift"
-Neutrophils (WBCs) are the body's primary defense. -segmented neutrophils=mature form -banded neutrophils=immature form-Obtained from CBC with differential -Left Shift=an increase in the relative number of immature forms of neutrophils (>10%) -clinical marker of acute inflammatory/infection -inc. b/c bone marrow keeps pumping out as others are being eaten-Neutrophilia (leukocytosis) (condition of raised WBC count) w/o left shift may occur when the body is stressed (ex exercise, anxiety, "fight or flight")
what are streptogramins used to treat
Vancomycin resistant gram + infections
What is the mechanism of action of daptomycin?
alters ion flux
Quinupristin binds at same site as macrolides. Dalfopristin binds nearby and deforms 50S ribosome ; enhances Quinupristin binding.
Regimens used in H. pylori infections and ulcers
BMT: bismuth, metronidazole, tetracyclines or clarithromycin, amoxicillin, omeprazole
what 4th gen FQ causes severe hepatotoxicity
trovafloxacin-removed from USA market
which antibiotics do NOT require dose adjustment in renal failure (6)

hint: 4 B-lactamase resistant penicillins and 2 3rd gen ceph's
-COND: cloxacillin, oxacillin, nafcillin, dicloxacillin
How does Tetracyclines inhibit protein systhesis?
By blocking attachment of aminoacyl-tRNA to
How are cephalosporins and penicillins similar in structure?
Both have beta lactam structure.
a PCN -  ie. Amoxicillin
What should you use in combination with Clavulanic acid to broaden the coverage?
What is the best treatment for CA-MRSA?
b/c it makes the worried doctor be able to sleep at night since it will treat group A strep just in case CA-MRSA is not the cause
this drug could cause steven johnson(2 drugs) + hemolytic anemia.
Septra DSNevirapine-cause only steven johnson
Mechanism of resistance to sulfonamides
Change in target enzyme decreases drug sensitivity; formation of PABA; use of exogenous folic acid
cefepime gets thru ____ because its a _____
porins of G- envelopes
What are the side effects of Sulfonamides in the Blood?
1-hemolytic and aplastic anemia, 2-thrombocytopenia
How can drug resistance be limited?
Maintain high levels of antibiotic long enough to kill all pathogens, administer 2 antibiotics simultaneously so they can exert an additive effect (called synergism), restrict antibiotic use to essential uses only, finish prescriptions, and culture the bacteria to know the correct antibiotic(s) to use.
Clindamycin can be used to treat two other things...
bone and joint infections (staphylococcal or anaerobic osteomyelitis)
acne vulgaris (topical preperations)
What are the adverse effects of tigeglycine?
N/V sometimes severe especially in young otherwise healthy patients
47. In the treatment of infections caused by P. aeruginosa, the antimicrobialagent that has proved to be effective isa. Penicillin Gb. Piperacillinc. Nafcillind. Erythromycine. Tetracycline
piperacillinThe answer is b. (Hardman, pp 1077–1086.) Piperacillin is a broadspectrum,semisynthetic penicillin for parenteral use. Its spectrum of activityincludes various Gram-positive and Gram-negative organisms includingPseudomonas. The indications for piperacillin are similar to those for carbenicillin,ticarcillin, and mezlocillin, with the primary use being suspected or proven infections caused by P. aeruginosa. Penicillin G, nafcillin,erythromycin, and tetracycline are ineffective against Pseudomonas.
considered the HOLD BACK drug of AG's

reserved for bugs that are resistant to other AG'S
Macrolides are distributed to most tissues and body fluids except one, which fluid is that one?
The CSF (only when meninges are inflamed)
Administration of penicillin Na+ can lead to what?
Hypokalemia bc more Na+ will be reabsorbed in the distal nephron.
importance of oxygen for aerobes and anaerobes
-molecular oxygen is very reactive and toxic -H2O2-hydrogen peroxide -O2 super oxide radicals -OH- hydroxyl radicals-Macrophages pour oxygen radicals over bacteria-three enzymes break down radicals -if bacteria has it, they will be resistant
The most active aminoglycoside against Mycobacterium tuberculosis isa. Streptomycinb. Amikacinc. Neomycind. Tobramycin
49. The answer is a. (Hardman, pp 1105–1108.) The activity of streptomycinis bactericidal for the tubercle bacillus organism. Other aminoglycosides(e.g., gentamicin, tobramycin, neomycin, amikacin, and kanamycin)have activity against this organism but are seldom used clinically because oftoxicity or development of resistance.
what are the 3 mechs of resistance for AG's
ribosomal resistance
resistance cuz of transporter(rare)
metabolic pathways to resistance(IMPORTANTEEEE)
methods/procedures that can help stop the spread of infectious diseases
wash your hands, don't share food, & wash vegetables
Will grow - enterococci
will not - streptococci
What organism will grow in NaCl? which one will not?
70. The mechanism of action of chloroquine in Plasmodium falciparummalaria is elimination ofa. Secondary tissue schizontsb. Exoerythrocytic schizontsc. Erythrocytic staged. Asexual formse. Sporozoites
70. The answer is c. (Hardman, pp 970–972.) Chloroquine is a 4-aminoquinoline derivative that selectively concentrates in parasitized redblood cells. It is a weak base, and its alkalinizing effect on the acid vesicleof the parasite effectively destroys the viability of the parasite
Why are CD4 & viral load counts monitored in HIV positive patients?
to determine how severe the HIV is
(AG) phase 1 is inhibited by
Mg or Ca, low pH, and low O2
the pump that transports AG's requires O2
97. A 20-year-old male has a urethral discharge. Culture of the dischargeshows Neisseria gonorrhoeae. Which of the following agents is the best choicefor treating this patient?a. Ceftriaxoneb. Benzathine penicillin Gc. Imipenend. Amikacine. Sulfamethoxazo
97. The answer is a. (Hardman, p 1082. Katzung, pp 764–766.) The thirdgenerationcephalosporin, ceftriaxone, and cefixime are considered firstlinedrugs in the treatment of gonorrhea because most strains of Neisseriagonococci are resistant to the penicillins. Amikacin and other aminoglycosidesare used in serious infections caused by E. coli, Enterobacter, Klebsiella,and Serratia species. However, spectinomycin, which is related to theaminoglycosides, can be used as a backup drug for gonorrhea.
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