Unit 3 Part 2: Chpts 38-47 Flashcards
What are the factors that affect what anit-infective agent you chose/
1) necessity of agent
2) diagnosis of pathogen
3) sensitivity testing
4) location of infection
5) renal/hepatic function
6) status of host defenses
7) monitoring of therapy
Bacteriostatic vs bacetirocidal
bacteriostaic- suppresse growth without killing microbes–> holds # at bay while body units work
bactericidal: directly destroys the organism–> evantually if disease/organism cannot replicate–> pt physiological defenses(if strong) will be able to collect debirsi and fight off(like suice or homicide)
Classification of antimicrobials
Mechanism of action
1) spectrum of activity
broad spectrum- exert affects agianst a number of different types of bacteria and other organisms
narrow spectrum- exert affects primarily on one group of organisms
what are the mechanisms of actions for antibiotics?
1) inhibition of bacterail cell wall–> cannot sustain life(ex penicillin)
2) Disruption in cell membrane–> makes porous and allows bad things to get in= no longer functional barrier or cell
3) inhibit protein synthesis-ex tertracycline
4) antimetabloites- disguises it self as another
5) inhibition of nucelic acid synthesis
6) inhibition of viral enzymes– acyclovir
What is selective toxicity?
imp part of antimicrobial therpay
the ability to suppress or kill and infectein microbe wihtout injury to the host
Penicillin G
- Beta- lactam antibiotic
- closely related to cephalosproins
- most widely used antibiotics
- inhibits bacterial cell wall synthesis
- most serious adverse effect: hypersenstivity
- most common: n/v/d
- take on empty stomach
- monitor I&O’s for kidney dysfunction: poss toxicity
- stops meds if allergic response occurs
- lowers eff. of OCT’s
- increases effect of anticougulant
- increases methotrexate toncitiy(chemo)
- interferes with action of tetracyclines
- contridicitaed if allergic response before
- commonly used for syphillis, gonorrhea, staph and strep
Always give:
antibiotic for lowest dose of best drug for shortest time
cefazolin
cephlasporins: similar chemically and pharmcolofically to PCN
*interfest with bacterial cell wall synthesis
First generation: cefazolin
- commonly used for septicimia, klebsiella, infections of the skin, Soft tissues, bones, resp. tract and UTI
- X-snesitivty with PCN- dr will outway contridications
- Etoh creates a “disulfuram” reaction: v/d/cp/sob/flushing –> take 72hours after antiobiotics
- kills intestinal flora whihc lowers VIT K –> used for clotting –> watch out for ppl on warfarin or coumadin
- major contraindication: hypersensitivity to cephlasporins/PCN
- major serious adverse effects: hypersensitiivty
common: n/v/d - cautiously used for elderly with renal insuffciency
- IM- give in large muscle mass
- observe for bllod diarrhea–> could be pseudo membranous colitis –> MD STAT
- caution with renal disease, pregnancy, adn lactation
Vancomycin
inhibits bacterial wall syntheisis
*used for treating:
chronic bone infection, GU infections, Intraabdominal infections and speticiemia
* major contraidication: prefnancy and hypersnesitivy
*common: histamine release resulting in red mans syndrome
* seriopus: ototoxicity and nephrotixicity and exerts addtivite effect wiht other toxic drugs –> monitor renal output, daily weight, BUN, creatinine, I&O
*must be given over less than 60 min per 500mg
excessive speed–> red mans syndrome
* profound histamin release wiht flushing of the neck, head, Hypotension, sweating and vascular colloapse if not recognized–> not a allergic response–> due to rate related
*take peridoc CBC and let dr know if there is any hearing loss
Gentamicin(amnioglycoside)
interferes with protein synthesis
- treat such thing as TB, pseudomonas, GI tract infections or PREP OP care
- contraindications: hypersenstivity, pregnancy and breast feedin
- common: n/v/d/weight loss, hepatobiliary- elevation in liver enzymes
- most significant effect–> renal
- black box warning: neuro, nephro, otoxicity an neuromuscluar blockade
- monitor: I&O”s, BUN, creatinine
Clindamicin(lincosamides)
interfere with protein syntehiss
* used for life threantining infection(strep, pneumoina adn speticiemia)
*Contraindication: pregnangct, lactation, hypersentsiticy, renal/hepatic dysfunciton
* common: n/v/abd pain, rash, and prutis
*most serious- psedomembranous colitis; EXFOLIATIVE DERMATITIS(scalded skin syndrome)
*toxicities- renal;oto and neuromusclar bloakce resulting in confusion, depression, disorientation and resp derpresion
* GIVE 2 HOURS PRE-POST PCN IVPB’S
GIVE WITH FOOD
*if diarrhea >5 days contanct MD bc likley C diff or enterisits *rapid infusin can cause KG cahnges, hypotensiona dn cardiac arrest
*if pt has heptaci/renal issues- reduce does
*can descrease levels of cyclosporine(immunosuppr. for transplants) monitor levels
Erythyomycin(macrolides)
inhibit RNA dependent protein syntheisis
- used for resp., GI , skin, and soft tissue
- strep, diphteria, atypical penumoias
- used for pts allergic to PCN
- give on empty stomach
- common: GI distress
tetracycline
broad spectrum *inhibit protein syntehsis *used for treatin rickettsial infections *alt. for treatment for PCN allergic pt to gonnorrhea and syphillis *Category D- dont let mothers take it * binds to Ca and attaches to teeth and bones--> no child under 8 should get--> will leave horzantel stripes on pernamanet teeth * give on an empty stomach * keep out of reach of children * n/v serious_ azotemia
Chloramphenicol
- inhibits protein synthesis
- braod spectrum: meningitis, rickettisal infections, bacterial septicmiea
- CI: hypersenticity, breast feeding
- headche, n,v,d
- give on empty stomach
- serious: blood dyscraisis: grey baby syndrome
- balck box warning: anemia poss.
Cirpofaloxcin(quinolones)
destroy bacteriae by altering DNA
- lower resp., uti, stds
- increase effect. of warfarin
- increase action of sulfonylureas(antidiabtic agent–> at risk for hypoglycemia)
- metablozied by liver 450–> potentil interactions
- decrease cyclosporine meta.–> not using as fast= poss toxicity
- lower hyfantoin levels–> for seizures–> increase risk for seizures
- common: Gi
serious: anrthopathy in pts >18 yrs olf bc still growing muscles and tendons - increase risk for tendonitis and ruptures.
- avoid exercise with this drug
