Antibiotics 3 Flashcards

Terms Definitions
sulfonamides
gentmicin
Alcomicin,Garamycin
Augmentin
Amoxicillen/Clavulanate
Zefazone
Cefametazole
Keltab
cephalexin
Gram -
-peptidoglycan-lipopolysaccharide-porin channel-periplasmic space-PBPs-beta lactamses
lyme disease
doxycycline
Foscarnet
Foscavir (antiviral)
gentamicin/betamethasone
Garasone,Valisone G
ampicillin
Omnipen (aminopenicillin)
Dosing of macrolides?
tid
qid
Trimethoprim/Sulfmethoxazole mechanism of action
Characterize Streptococcus.
Gram+CoccusFacultative anaerobecatalase-
penG aka
benzyl penicillin
RNA Polymerase Abx
-Rifampin
silver sulfadiazine
Silvadene (sulfonamide)
Diflucan
Antifungal - Fluconazole
serratia marcescens
klebsiella-enterobacter serratia group-virulence -endotoxin -red pigment strains may be more virulent-multiple mechanisms of antibiotic resistance including beta lactamase production-diseases: UTIs-pyelonephritis and cystitis, nosocomial pneumonia and bacteremia, infective arthritis-from intra-auricular injections
Rickettsia(scrub typhus), Mycoplasm, Chlyamydia, & Plasmodium(e.g.malaria) are effectively treated with
tetracyclines
Streptogramins
Quinupristin & dalfopristinBind different sites on 50S; bacteriostatic separately/bacteriocidal together. Block peptide elongation and peptidyl transferase; Use against Gram+, VREF and Vancomycin resistant Staph
CA-MSRA
T/S trimethorprim / sulfamethoxazole
FQ's elimination
liver-moxi, gemi(61%), Trov

renal-cipro, levo
DOC for chlamydia trachomatis
Doxycycline
cefPOdoxime
-3rd gen ceph
-PO
-tx gonorrhea
Antipseudomonal Penicillin spectrum
Pseudomonas (gm-)
Protein Synthesis (50s) Abx
-Erythomycin
-Choramphenicol
-Clindamycin
-Lincomycin
cefoxitin
Mefoxin (2nd generation cephalosporin)
Antibacterial
*Cell wall synthesis inhibitors*Penicillins, cephalosporins
staphcorynebacterialisteriaB. anthracis
gram +, facultative anaerobes
peptidoglycan
structural intergrity of cell wall
Cephalosporins in general
Bactericidal.Good against penicillinase.Large/wide therapeutic window.Variable CSF penetration.Not very good against pseudomonas.Not good with atypical respiratory pathogens.Take care with pts who have penicillin allergy.
What are the anti-staphlococcal PNC?
Methacillin
Naficilling
Oxacillin
Cloxacillin
Dicloxacillin
meropenem niche
nosocomial infections, febrile neutropenia, ...
legionella and mycoplasma
erythromycin (atypical pneumonias)
Linezolid
VRSA, VRE, drug-resistant pneumococci. Side effect: bone marrow suppression (platelets)
DNA gyrase drugs
FQ-alpha subunit
Novobiocin-Beta subunit
aminopenicillins coverage
SS HEMP +B

Salmonella
Shigella
H.flu
E.coli
MCAT
Proteus mirabilis
B.frag (G-bacilli: must combine with B-lactamase inhibitor)
True/False. Macrolides and Lincosamides inhibit RNA-dependent protein synthesis by acting on a small portion of the ribosome (50 S).
True
Ciprofloxacin
Fluoroquinolones, excellent gm- (H. flu), decent gm+, excellent shigella & salmonella
Localized presence and multipication of microorgs w/out invasion or damage
Colonization
ADE Rifampin
-Stains body secretions orange
Dormant/stationary phase bacteria are generally harder to kill*Bacteriostatic antibiotics ultimately rely on the host immune system for clearance*
*Antagonism*
Which cephalosporin is used prophylactically before surgeries?
Cefazolin
Penicillins
Cephalosporins
Monobactams
Carbapenems
What are the 4 beta-lactam antibiotics?
E. coli causing enteric infections (diarrheagenic)
-Entrotoxogenic-ETEC-Enteropathogenic-EPEC-Enteroinvasive-EIEC-Enterohemorrhagic-EHEC, EC O157:H7-Enteroaggregtive-EAggEC
2nd generation Cephalosporins

Cefuroxamine, cefactor, cefoxitin, cefiximine, cefotetan
active against G- and pen'ase, E coli, Klebsiella, Proteus, H. influenzae, M Caterrhalis
Not as good against G+ as 1st gen
Flucytosine
Antifungal. Oral only; well absorbed. Good distribution including CSF. Excreted in urine so must adjust in renal failure. Can cause leukopenia, thrombocytopenia, hepatic enzyme elevation.
gentamicin niche
aerobic gram negative rods, synergistic with cell wall active agents (beta-lactams and vancomycin) for gram positive cocci.
piperacillin
block cell wall synthesis by inhibiting peptidoglycan cross linking
shigellosis, salmonella, enteropathogenic E. Coli
T/S trimethorprim / sulfamethoxazole
Second generation cephalosporins
Cefotetan, cefaclor, cefuroxime. Increased gram- coverage, including some anaerobes
Ganciclovir
Activated by viral thymidine kinase, inhibitor and chain terminator of DNA polymerase. Use for HSV, VZV, CMV, AIDS retinitis and transplant patients. Side effects: hematotoxicity, crystalluria, rash
Neomycin S.E.
NOT for systemic->most OTO/renal toxic

cause rashes when used topically
ceftazidime

-effective against___
-DOC for___
-susceptible to ___
-pseudomonas aeruginosa
-X BBB --> DOC for pseudomonal meningitis
-easiest ceph to be cleaved by ESBL
T/F Third Generation Cephalosporin has No activity against enterococcus.
True
When was the Penicillins first introduced?
1940’s
Systemic infection in which pathogens are present in the circulating bloodstream
Septicemia
ABx with good Lung Penetration [2]
-Quinolones
-Macrolides
What drug works by stoping DIHYODROPTEROATE SYNTHETASE?
SULFONAMIDES
*Other*Cell membrane disruptionFatty acid synthesis – triclosan, tuberculosis drugs)Antimetabolites (sulfa, trimethoprim)
Bacteriostatic vs. Bacteriocidal
quin Ther.
uti's, prostatitis, stds... canchroid, clamyds, not syph or gons bc increased resistance

UPS
Trimethoprim for...
gram (-) pathogens NOT anaerobes
Penicillins
What type of antibiotics are usually safe in pregnant women?
antimicrobial assays
-generally useful when the antibiotic has a "narrow therapeutic window" -the effective level is close to level that produces toxicity-aminoglycosides-elimination solely by kidneys so if kidney failure occurs, dosing must also (nephrotoxicity/ototoxicity)-vancomycin (same)
Skin
-Acid pH from normal flora and sebaceous gland secretion-Mucous membranes -Mucus (moistens and protects) -Lysozymes -Secretory antibodies (IgA)
rashes and bone marrow depression of ae of what
sulfonamides
What drug is in the glycylglycine class?
tigeglycine
gentamicin toxicity
nephrotoxicity and 8th cranial nerve (hearing and balance), must monitor serum levels. Toxicities of concern when combine with vancomycin.
Fluoroquinolones
Expanded use of quinolones to both Gram Positive AND Negative bugs.
Gram stain of Bacteroids fragilis?
Gram negative rod
Uses of azithromycin
Gram+ cocci, atypicals (chlamydia, mycoplasma, ureaplasma), legionella, campylobacter, more activity in respiratory infections
AG combo to tx Enterococcus
Ampicillin + gentamicin
Clofazimine
phenazine dye-binds to DNA and inhib. template function-?ca't replicate + transcribe
treatment of high-resistance step. pneumoniae
-vancomycin + ceftriaxone
-levofloxacin/moxifloxacin are alternatives
treatment of low-resistance strep. pneumoniae
normal penG dose
Is Aztreonam active against Gram – rods including Pseudomonas.
True
Erythromycin
Macrolides, gm+, gm- (H. flu), genital pathogens
Fluoroquinolones Adverse Effects [5]
-Tendon rupture
-Prolonged QT interval
-CNS effects
-Phototoxicity
-Not recommended for children
a antifungal drug available in liposomal or lipid complex form
amphotericin B
pt w pen allaergies
switch to diff abx
Quinolones / floxacins
DNA topoisomerase II inhibitors; ciprofloxacin; UI, osteomyelitis, prostate
Is renal impairment reversible?
may be reversible on d/c
Extended-Spectrum penicillins
What type of penicillins are destroyed by beta-lactamases and are most active against Klebsiella, Enterobacter, Serratia, & Proteus?
Enteropathogenic EPEC
watery diarrhea, N & V, fever, children
Vancomycin
binds to end of D-Ala bacterial cell wall building block, prevents cross linking by transpeptidase, inhibits bacterial RNA syn
Parenteral (unless tx for GI), broad distrib. except CSF, renal elim
G+, S. auereas, S epidermis, strep, enterococci, Corynebacterium, Clostridium, MRSA
Penase resistant, Pen sensitive
Ototoxic, rare nephrotoxicity, His release(redman)
What is a possible side effect of daptomycin but is often not seen when it is given in lower doses?
rhabdo
doxycycline mechanism of action
Bacteriostatic. Inhibits the 30s ribosomal subunit.
Drugs that inhibit Nucleic Acid Biosynthesis
Sulfonamides, trimethroprim, floroquinolones, nitroimidazole, rifamycin
Inhibitors of nucleic acid synthesis drugs
Sulfonamides, trimethoprim, pyrimethamine
Tigecycline MOA
AKA
Binds 30S at the A site->prevents protein synthesis
bacterioStatic

glycylcline
leprosy is caused by..
another name for leprosy...
mycobacterium leprae

Hansen's disease
2nd gen ceph coverage
-less G+
-more G- "HEN PEcK"

H.flu
Enterobacter
Neisseria
Proteus mirabilis
E.coli
Klebsiella
aminopenicillins are effective against G- because they're ____ thus able to pass thru ____
zwitterions
porins of G- envelopes
What does Sulfonamides prevent synthesis of and How?
Folic Acid through diet
troche
solid dosage form with a flavor base that is intended to dissolve slowly in the mouth
What are superinfections?
Infections caused by antibiotic use (kills off normal flora, changing the environment, and making the patient more susceptible to other infections).
Sulfonamides - Sulfamethoxazol
folate syn inhibitor via comp. inhibition of dihydropteroate synthase and reducing dihydrofolic acid levels; high plasma protein bound, displace bilirubin in neonates = hyperbilirubinemia; potentiates phenytoin (antiseizure), warfarin, and oral hypoglycemics
How are tetracyclines (esp doxycycline) classified?
long acting, lipophilic, hepatic elimination, bid dosing
Colon Cancer
If you have a positive blood culture for strep bovis, what other disease should you look for?
concentration dependent killing
the antibiotic continues to exert its killing effect after the concentration has fallen below the bacteria's MIC (post antibiotic effect). The HIGHER the PEAK, the GREATER THE KILLING EFFECT. -ex, aminoglycosides and fluoroquinolones
First Generation Cephalosporins
Good for G+, steptococci, s. auereas (except MRSA),
 not good for G- (except some E. coli, K pneumonia, P. mirabilis)
poor for anaerobes, enterococci, and listeria
Cross reactive with penicillins

Cephalexin, Cefazolin, Cephalothin, Cephradine
What is the drug in the class of oxazolidinones?
Linezolid
does mefloquine enter CNS?
yes it causes mental status changes
C. difficile: aerobe or anaerobe?
C. diff is an anaerobe
Drugs that inhibt viral aspartate protease
Indinavir, ritonavir, saquinavir, nelfinavir
CYP 450 inhibitors
Clearly, Cool Kens Vehicle is Equally Quick

Chloramphenicol
Clarithromycin
Ketoconazole
Valproic Acid
Isoniazid
Erythromycin+Telithromycin
Quinolones,Q/D
cefepime is DOC for ____ because it crosses ____ and is resistant to ___
pseudomonal meningitis
BBB
ESBL
Where is Ribavirin metabolized?
In the liver and by RBCs
Guiding Principles of Antibiotic Tx [5]
-Right dx
-Eliminate source
-Correct abx
-Do no harm
-Antibiotic use promotes bacterial resistance
What route can Penicillin V/VK be given?
PO; no IV,IM
What are aminopenicillins indicated for?
(ampicillin, amoxicillin) E.coli, P. mirabilis, H. influenzae.
What is used for prophylaxis for gonoccocal and chlamydial ophthalmia neonatorum
erythromycin topical 5% ointment
Coagulase-Negative Staphylococcus - CNS
Which bacteria are not capable of making the disease by themselves unless they have a reservoir like a catheter?
treatment for moraxella catarrhalis
-used to be exquisitively sensitive to penicillin-1980s beta lactamase producers (chromosomally anad plasmid mediated)-most remain sensitive to erythromycin, tetracyline, amoxicillin/clavulanic acid (augmentin), and cephalosporins (none are more superior over others)-most infections involve oral mucosa, oral antibiotics are usually OK. pneumonia/bacteremia-parenteral AB's (intravenously)
What is the mechanism of action of clindamycin (lincomycin)?
 
is it bacterialstatic or cidal
50 s inhibitor
static
what is a good group of antibiotics for atypical pneumonia?
macrolides --specially erythromycin
Gram stain of Staph. epidermis?
Gram (+) cocci, cluster, coagulase (-)
(AG) what happens in metabolic pathways to resistance
conjugating enzymes inactivate the drug thru: acetylation, adenylation, phosphorlyation,
ceftriaxone is DOC for ____ & _____
Neisseria gonorrhea & penicillin-resistant strep pneumoniae (+ vanco for G+)
What is the antiviral spectrum of Ribavirin?
Antiviral Spectrum:pediatrics with severe RSV infection, some efficacy against acute hepatitis A, influenza A, and influenza B reported
Usually Oral, IM, subQ or IV-IV has fastest delivery, oral usually slowest-Some drugs are restricted in method of delivery – e.g. some are not absorbed from the GI tract efficiently, some are not tolerated well from IV delivery
Some inhaled, topical
at 4 hours
If you are giving a drug every 8 hours, at how many hours would you still want it above the MIC?
what are cautions of quinolones
damage joint in immature animals so dont give to kids less than 14, absorption interactions
What spectrum is Bacitracin?
Bacitracin is useful against G + organisms
Drug interaction of zidovudine (ZDV, AZT)
Increase levels of ZDV: azoles, cimetidine, indomethacin, probenecid, TMP-SMX. Decrease levels of ZDV: rifampin
2nd generation cephamycins stable to ___ &___ but not___or____
stable to mild cephalosporinases and ESBL, but not to Amp-C or metallo-B-lactamases
True/False. Quinolones do not have excellent oral absorption.
False, they have excellent oral absorption.
Frequently encoded on large plasmids or transposons and thus highly mobile-A pathogen can acquire multiple resistances very rapidly
Some drugs reserved for problem cases-Zyvox?
Explain how tetracyclines can cause deposits in crown of anterior teeth?
Crown formation complete by 6-7 years, high risk of permanent teeth discoloration when used in children less than 8 years (least likely to occur with doxycycline but should avoid all tetracyclines in children less than 8 years and in pregancy)
rifampicin acts how... ad used in the px and rx of what
inhibit bacterial rna polymerase, meningococcol dz.. also use on staph and mucobacteria
88. A 75-year-old male develops a cough that produces blood-tinged sputum.He has a fever of 104°F. Gram-positive cocci in clusters are found in asputum smear. A chest x-ray shows increased density in the right upperlobe. Of the following penicillins, whi
remember b4 reading -- pipercillin (ticarcillin and carbenicillin) all are given with Tazobactam to broaden the spectrum for B-lactamases88. The answer is c. (Hardman, p 1086.) Ticarcillin resembles carbenicillinand has a high degree of potency against Pseudomonas and Proteus organismsbut is broken down by penicillinase produced by various bacteria, includingmost staphylococci. Oxacillin, cloxacillin, nafcillin, and dicloxacillin are allresistant to penicillinase and are effective against staphylococci.
what is grays syndrome and what causes it
infants unable to conjugate chloramphenicol
sympt-abdominal distention, vomiting, cyanosis
Why and how is Oxymetazoline used against sinusitis as a form of non-antibiotic tx?
Oxymetazoline is a selective alpha-1 agonist and partial alpha-2 agonist topical decongestant, found in products such as Afrin, Dristan, Nasivin, Vicks,Sinex, Visine L.R., and Zicam. It is available as a nasal spray.
2nd generation cephs
modest vs gm + , incr activity vs gm -
works vs anaerobes
cefaclor and cephprozil given orally
abs and secret like 1st gen
good for tx resp tract infect, intraabdominal infection, pid and diabetic foot ulcers
Vancomycin + metronidazole + ciprofloxacin
What drug would you use for a pt allergic to PCN who has necrotizing fascitis with mixed aerobes and anaerobes?
Is Vancomycin absorbed in the GI tract?
No, and it is usually given IV
Sulfonamides:
- general class by mech?
- mech of action?
- therapeutic uses?
- pharmacokinetics?
- Major Toxicities?
- Drug/Drug Interactions
- Resistance Mech?
DNA synth inhib

- analog of PABA; inhibit folic acid synth.
- inhibits pteroate synthetase

sulfadiazine + pyrainamide for toxoplasmosis
- used to tx other things in combo w/ TMP

SMZ + TMP b/c they have similar pharmacoK profiles.

- Kernicterus (jaundice)
- Hematopoietic disorders
- Hypersensitivity (skin rashes)

Inhibits warfarin degradation by interfering w/ P450

- Mut in pteroate synthetase
- increased production of PABA
Why does the Sulfonamides want to prevent the synthesis of Folic Acid?
To promote the synthesis of purines and nucleic acid.
What is the DOC for urogenital infections caused by C. trachomatis?
doxycycline is the DOC for STDs (like non-gonococcal urethritis)
60. A 39-year-old male with aortic insufficiency and a history of no drugallergies is given an intravenous dose of antibiotic as a prophylaxis precedingthe insertion of a valve prosthesis. As the antibiotic is being infused, thepatient becomes flushed ove
60. The answer is a. (Hardman, p 1146.) The “red man” syndrome isassociated with vancomycin, thought to be caused by histamine release.Prevention consists of a slower infusion rate and pretreatment with antihistamines.
Do humans have DNA gyrase and Topoisomerase IV?
No, which is why Quinolones are used for humans.
What are TMP/SMZ used to tx? (4) Is this combo narrow or broad spectrum?
UTIs
RTI caused by h. influenzae and s. pneumoniae
shigella enteritis
Pnuemonia caused by pneumoncystic carinii (i/AIDS pts)
95. A 30-year-old type I diabetic with renal complications develops acutepyelonephritis. P. aeruginosa is found in urine cultures and blood cultures.Combined therapy is instituted with an aminoglycoside and which of thefollowing?a. Clavulanic acidb. Vanco
95. The answer is e. (Katzung, p 761.) Piperacillin is effective againstP. aeruginosa. The ease with which these organisms develop resistance withsingle-drug therapy has necessitated that combination with aminoglycosidesbe used in pseudomonal infections.
nocardia
sulfonamide
Tegopen
Cloxacillin
Mefoaxin
Cefaxitin
Cefzil
cefprozil
Rifampin analogs
rifapentin
rifabutin
Terbinafine
Lamisil (antifungal)
Spectracef
Cefditoren pivoxil
fluconazole
Diflucan (antifungal)
streptococcal disease-localized infection of healthy skin-usually affects kids 2-5 yrs-vesicles are contagious, but lesions do not usually result in scarring-staph aureus sometimes a secondary invader -nephritogenic strains -first acute, the
impetigo
bacitracin
blocks peptidolycan synthesis
2 Quinolones
Nalidxic Acid
Cinoxacin
Ticarcillin
Antipseudomonal Penicillin, pseudomonas
DNA Gyrase Abx
-Quinolones
ciprofloxacin (PO)
Cipro (quinolone)
Chloramphenical-overdose
Grey baby syndromeNVC
Blood
-WBC's, antibodies (IgG,IgM), complement (activated by bacteria in bloodstream)-Reticuloendothelial system -Migrating RES (monocytes and macrophages) -Sessile RES (Kupffer cells-liver and spleen-filter out bacteria and remnants)
Ceftriaxone
3rd generation cephalosporinActive against gram -ves and +ves.Long half life; distributes well.Good for meningitis.Bad for babies.Most pts ok in renal failure.IV administration.
Nitroimidazole
metronidazole and tinidazoleDamages DNA; kills anaerobic bacteria, fungi, and parasites; Given with B-lactam
Name 2 important anaerobes
ClostridiumBacteroides
PZA S.E.
hepatotoxic(addative with isoniazid)-stop after first 2 months

causes hyperuricemia
timentin
ticarcillin + clauvalanic acid
Haemophilus influenza category
Gram-negative Bacilli
Atypical Organisms [3]
-Mycoplasma
-Legionella pneumophilia
-Chlamydia sp.
imipenem-cilastin
Primaxin (misc. related antibiotic)
Efudex
Contraindicated with hypersensitivity and pregnancy
absorption insignificant (6%)
- Inflammatory response may occur with occlusive dressings
- Adjacent healthy skin around warts should be coated with protective gel
- Reproductive age should use adequate contraception during therapy
ADVERSE: burning, crusting, pain, scarring
mycoplasma
no cell wall, facultative anaerobe
Bacterial Cell Wall Structure
-Peptidoglycan layer-Lipopolysaccharride layer-Porin channels-Periplasmic Space-Penicillin binding proteins (PCB's)-Drug altering/destroying enzymes -plasmids -chromosomes-Nucleus (30s and 50s ribosome, DNA) -areas to attack microorganism
Oxacillin
Antistaphylococcal.Not good for MRSA, gram -ves, anaerobes.Good against GAS and MSSA. Poorly absorbed orally.May cause leukopenia.
What does SCCmec code for?
PBP2
Amino-penicillins
ampicillin, amoxicillin (more active against Gram- than natural penicillins
Define MBC
MBC (Minimum bactericidal concentration)- lowest concentration of the drug at which 99.9% of a culture is killed after 18-24 hrs incubation in vitro
Aminoglycoside drugs
Gentamicin, tobramycin, amikacin: gram- aerobic rods (pseudomonas, brucella, legionella); Streptomycin: TB, plague and tularemia; neomycin
Telithromycin coverage
S. pneumoniae (**+ penicillin/erythromycin resistant strains)**

H.flu
Legionella
M. Cat
Chlamydia
3rd gen. FQ drugs
systemic- Levofloxacin
Gemifloxacin
which cephalosporin effective against MRSA/MRSE
NONE!!!
True/False. Amantadine should be avoided in pregnant and nursing mothers.
True
Gentamicin & Tobramycin (Aminoglycosides) toxicity
otoxicity, nephrotoxicty
Abx for Serretia sp?
-Gentamycin/Tobramycin (Aminoglycosides)
some opportunistic infections
TB, PCP, MAC
imipenems
broad spectrum including anaerobes
and pseudomonas
parenterally
combine w cilastin to be absorbed
excreted by kidney
Adverse rxn with pen V?
hyokalemia
nephrotoxicity & ototoxicity
What toxicities do aminoglycosides cause?
Killing Properties of Antibiotics
-interval dependent killing-concentration dependent killing
what does gentimicin do
synergizes with vancomycin
Zanamivir
Therapy for influenza.Taken as an inhalant for five days.May cause bronchospasm.Neuraminidase inhibitor.
Vancomycin spectrum
Gram positives, especially resistant ones.
Define PAE
PAE (post-antibacterial effect)- When suppression of bacterial growth continues after the antibiotic concentration falls below the bacterial MIC
Drugs that are nephrotoxic
Vancomycin, aminoglycosides, amphotericin B, cisplatin, cyclosporine
MOA of azoles
Fungicidal by inhibiting 14-alpha-demethylase which converts lanosterol to ergosterol
tx of sepsis?
D.O.C. for septicemia from lung origin
Aminoglycosides

ceftriaxone
DOC for rikettsia
TCN
-rocky mountain spotted fever
cefaclor frequent side effect

hint: side effects make you "sick"
serum sickness
ceftriaxone excretion
60% biliary, 40% urinary
in renal/liver failure, elimination will switch over to healthy organ
True/False. Aztreonam does not contain the bicyclic adjoining ring fused to the Beta-lactam ring.
True
True or False. Is Amantadine/ Rimantadine widely distributed throughout the body.
True
Loracarbef
Cephalosporins-2nd gen, same gm+ as 1st gen, addit gm- (H. flu)
Gram Negative Organisms [7]
-E. coli
-Pseudomonas aeruginosa
-Enterobacter sp.
-Acinetobacter sp.
-Stenotrophomonas maltophilia
-Serretia sp.
-Klebsiella sp.
Omniceft
Cephalosporins (cell wall synthesis) - Cefdinir (3rd)
What antibiotic is considered the least toxic of commonly used antibiotics and is often used against penicillin-resistant bacteria or in penicillin allergic patients?
Erythromycin
Valtrex
antiviral
absorbed GI tract, first pass metabolism
excreted in urine and feces
adverse effects: nausea, vomiting, abdominal pain, dizziness and headache
Tetracyclines
Protein syn inhibitors; binds 30s, prevents access of aminoacyl/tRNA to acceptor site on mRNA; chelates Ca
Quinolones
What type of abx inhibit DNA gyrase?
Other streptococcal diseases
-necrotizing fasciitis (skin eating strep)-wound and burn infections-puerperal infection-scarlet fever-immunologic sequella -rheumatic fever -acute glomerulonephritis
treatment for neisseria gonorrhea
-b-lactamase production has complicated treatment-ideal treatment involves >95% erradication rate with a single dose-regimen depends on site of infection and whether infections is complicated or uncomplicated-selected 2nd or 3rd generation cephalosporins, fluoroquinolones, spectinomycin are all effective
Chloramphenicol
Broad spectrum abx.Good drug but can shut down WBC formation.Contraindicated in neonates."gray baby syndrome"
What does USA 300 database indicate?
CA MRSA
treatment for T. brucei infeciton
suramin and melarsoprol
Antimicrobial drugs that go intracellular
ErythromycinEnrofloxacinLincomycin and clindamycin (not active)DoxycyclineRifampinSulfa/trimethroprim
Examples of 3rd generation cephalosporins?
Ceftriaxone, ceftazidime, cefotaxime
Uses of tetracyclines
Chlamydia, mycoplasma, H. pylory, Rickettsia, Borrelia, Brucella, Vibrio
Pharmacokinetics of ketoconazole
Orally effective; absorption decreased by antacids; metabolized by liver enzymes; inhibits P450
Isoniazid MOA
analog of Vit B6
inhibits synthesis +assembly by inhibiting ezyme resp for synthesis of mycolic acid
aztreonam cross-sensitivity
-very rare!
-CAN use with penicillin allergies
-LEAST cross-sensitivity amongst all B-lactam antibiotics
3rd gen ceph that covers B.frag

hint: "tiz fragile"
ceftizoxime
Where is the enzyme PBP’s located?
Cell membrane
Clindamycin
Misc, gm+ and gm- aerobes and anaerobes (better than Flagyl against), protozoa
Which cephalosporin does NOT need dose adjustments for renal dysfunction?
-Ceftriaxone
Bactrim AR
Sulfonamide (folic acid syn.) - Trimethoprim/Sulfamethoxazole
aminopenicillins used for
upper respiratory infections
otitis media
uti's
typhoid fever
bac mening in kids
Penicillin
cell wall syn inhibitor; acid labile, active tubular secretion; pen G parenteral only, pen V oral, binds PBP transpeptidases inhibiting transpeptidation of peptidoglycan crosslinking cell wall; Gram +
How is doxycycline eliminated?
Active biliary excretion and enterohepatic circulation (reabsorption); doxycycline half life unchanged in renal disease
What tetracycline is the DOC for Vibrio infections and what are two example of vibrio infections?
doxycycline
cholera, gastroenteritis
Respiratory Tract
-Ciliary action move particles out of the lung (move in one direction)-Cough Reflex-Mucous membranes protective factors
what drug is used to treat anaerobic trichomoniasis by reducing its nitro group that subsequently splits bact. DNA
Metronidazole
What is the MOA of Linezolid?
inhibits 50S ribosome
drug that is given as prophylaxis for GI surgery
neomycin
What advantage do the aminopenicillins have over penicillin G?
Significantly greater activity against gram- bacteria. Especially when combined with B-lactam inhibitors
Drugs that block viral penetration and uncoating
Amantadine, enfurvitide
Clarithromycins kinetics
better oral bioavail. (55%) then eryth or azith

cyp3A4 inhibitor
biliary(70%)
active metab-14-OH clarithromycin(2x eff than parent drug against H.flu)
if allergic to 1 penicillin...
...allergic to ALL penicillins
What is the mechanism of action of Aminoglycosides?
Bactericidal
tox contra of carbepenams
nausea vomitting (common) hypersens (uncommon) cross rxn possible except mono
What chemical structure is essential for antimicrobial properties?
B-lactam ring structure
The duration or exposure
With time dependent killing with antimicrobial drugs what are we trying to optimize?
Cephalosporins
What is the drug class of choice for surgery prophlyaxis?
PBP's (penicillin binding proteins)
-enzymes that congregate around cell walls -responsible for cross linking peptidoglycan strands -when anitbiotic binds with PBP's it causes strands to be loose, cell wall looses structure, cell wall degraded in both + and -
what stage of bacterial growth do fluoroquinolones, rifampin, and metronidazole act at
nucleic acid synthesis
List any toxicity associated with Vancomycin
Nephrotoxic, and hearing loss
TMP and SMX
both act on folate synthesiskills Gram +/- cocci or bacilli but not anaerobes
Uses for natural PCN?
mostly G(+), mostly streptococci (most mouth anaerobes)
Pharmacokinetics of aminoglycosides
Polar compounds not absorbed orally or widely distributed. Renal elimination. Modify in renal dysfunction
what type of MDR do FQ's tx
MDR M. tuberculosis
3rd gen ceph's

-excellent coverage of ____ and ____
-empirical treatment of ____ and ____
-less effective than 1st/2nd gen for ____
-strep pneumoniae and enterobacteriaceae (salmonella, E.coli, indole+ proteus)

-empirical tx of CAP (community-acquired pneumonia) and meningitis

-less effective for staph than 1st/2nd gen
What two toxicities are caused by Aminoglycosides?
Nephrotoxicitiy and Ototoxicity
Why are clavulanate & sulbactam combined with certain anitiobitcs?
inhibits beta lactamase activity
*Destroy/modify antibiotic (enzyme)*β Lactamases, CAT
*Limit access of antibiotic to target (keep it out of the cytoplasm)*Efflux pumps, mutation of active transport genes, capsules
Name 4 nucleic acid synthesis inhibitors:
Quinolones, sulfonamides, Rifampin, metronidazole
What interaction can tetracyclines have that decreases their absorbance?
Chelate with divalent and trivalent cations to form insoluble complexes which are not absorbed (dairy products, mineral and vitamin supplements, antacids, cathartics)
streptococcus pneumoniae URI
-common cause of sinusitis and otitis media
wwhat drug can be used to treat legionella, camplobacter, mycoplasma and all the drugs in the class end in omycin
erythromycin (class Macrolides)
What is the mechanism of action for Vancomycin?
Inhibits peptidoglycan formation
Telithromycin (Ketek®) MOA
Binds to 2 regions of the ribosome, making development of resistence less likely. (P450 inhibitor)
Mechanism of resistance to tetracyclines
Tetracycline pumps transport drug out of the cell
resistance mech for isoniazid
no cross resistance with other anti-TB drugs
ESBL

-found on ___
-cleave ___ and ___ with ___ group
-carried by ___ and ___ organisms
-extended spectrum B-lactamase, found on plasmids

-cleave several important 3rd gen ceph's + aztreonam (monobactam) with oxyimino group --> important bc these drugs are considered gold standard against serious G- infections

-klebsiella + E. coli carry ESBL
What are some of the non-antibiotic treatments employed in sinusitis that we discussed in class?
1- Phenylephrine or Oxymetazoline vasoconstrictor sprays or drops, 2- Phenylephrine or Neo- Synephrine, 3-Oxymetazoline
Why are streptomycin, erythromycin, tetracycline, and chloramphenicol harmful to bacteria, but generally not to the host cells?
They target the bacterial ribosome, which is different in structure from the eukaryotic ribosome. Toxicity may still occur because our mitochondrial ribosomes are similar in structure to the bacterial ribosome.
diagnostic focus with pharyngitis
-rule in or rule out Group A streptococci -Rapid Strep Test -Gold Standard (culture and susceptibility of throat swab)
What are the uses of Glycylglycine? (3 bacterias and one medical situation)
MRSA
VRE
Gram -
post op wounds
this drug creats harmless orange color urine.
Rifampin. SE: sweat, thrombocytopenia, nephritis, hepatitis
Pharmacokinetics of amphotericin B
Given by slow IV infusion, does not enter CNS, slow t1/2 > 2 weeks, hepatic metabolism and renal elimination
cefotaxime is alternative to ____ for ______

-covers ___
-lacks ___
-alternative to ceftriaxone for penicillin-resistant strep pneumoniae
-covers wimpy G+ anaerobes but not DOC
-no biliary sludging (unlike ceftriaxone)
What is a cause of Oxymetazoline?
It causes down-regulation of alpha-2 receptors, and therefore becomes less effective after a few doses.
Name 3 major ways that bacteria acquire antibiotic resistance.
Spontaneous mutations, gene swapping (conjugation, transformation, transduction), L forms (bacteria that spontaneously lose their cell walls).
Inhibit cell wall synthesis
What is the mechanism of action of all Beta-Lactam antibiotics?
How is vancomycin administered for C-diff?
 
Why?
oral
 
b/c it will stay on the enterocytes and will not be absorbed
What is the normal flora of the bronchi, trachea, accessory sinuses and middle ear?
these sites are usually STERILE!
(AG) what happens in phase 2
memb is more permeable-> gets slopy and leaks its own stuff->death
Why is TMP/SMX used as a common antibiotic tx for sinusitis?
AKA: Bactrim, 1-prevent intracranial complications, 2-help with the restoring and improvement of sinus functions, 3-eradicating the causative pathogen(s)
Minimum Inhibitory Concentration?
MIC - goal of therapy is to get plasma concentration above 50% of the MIC and maintain for appropriate amt. of time.
streptoccus pneumoniae -pneumococcal meningitis
-one of the big three causes of bacterial meningitis and the most common
imipenem is deactivated in kidney by an enzyme. to deactivate this enzyme and inc half life of imipenem a drug is given. please kindly give the name of the drug...
Cilastatin - by itself no bac activity
(AG) in phase 1 what happens when bacteria tries to wall itself off
bacteria produce protons which accum., decreasing pH->making AG ineffec.

must DRAIN abscess first
B vitamin given to patients being treated for TB & why?
pyridoxine (B6); to decrease risk of peripheral neuritis
clindamycin + ciprofloxacin, or cefoxitin
What drug would you give for a pt who has an established infection from an animal bite but is allergic to penicllins?
93. A 35-year-old female complains of itching in the vulval area. Hangingdropexamination of the urine reveals trichomonads. What is the preferredtreatment for trichomoniasis?a. Doxycyclineb. Pyrimethaminec. Pentamidined. Emetinee. Metronidazole
93. The answer is e. (Hardman, pp 995–998.) Metronidazole is a lowmolecular-weight compound that penetrates all tissues and fluids of thebody. Metronidazole’s spectrum of activity is limited largely to anaerobicbacteria—including B. fragilis—and certain protozoa. It is considered to bethe drug of choice for trichomoniasis in females and carrier states in males,as well as intestinal infections with Giardia lamblia.
What must happen to an individual for them to be allergic to an antibiotic
must have had a previous exposure (aware or unaware)
for every 1 pH unit decrease in the surrounding area of the drug, what happens to the absolute amount of unionized drug
10X increase in the amount of UNionized drug; the more unionized drug present, the less soluble it is and thus less drug enters the body
sequence of stage 1 of bacterial cell wall synthesis
1. UTP + NAG = UDP-NAG +PPi
UTP and NAG each lose 1Pi to bond
2. UDP-NAG + lactoyl = UDP-NAM T-shaped molecule is the final product of stage 1
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