68 terms

13-Antimicrobial Therapy

use of chem substances to treat disease; antibiotics; any med
chemotherapeutic agent
any chem sub used in medicine
antimicrobial agent
groups of chemotherapeutic agents used to treat disease caused by microbes
chem produced by microbes that kill or inhibit other organisms
synthetic drugs
drug synthesized in lab
semi-synthetic drugs
drug made by microbe then we alter in lab (penicillin)
selective toxicity
harm from microbe happens w/o significant host damage
spectrum of activity
range of microbes that are treated with antimicrobial; broad or narrow
broad spectrum
kills Gram + and Gram -
narrow spectrum
very specific, you know what disease you are treating
modes of action
what part of cell antimicrobial attacking; inhibition of cell wall synthesis, disruption of cell membrane function, inhibition of protein synthesis, inhibition of nucleic acid synthesis, action as antimetabolites
inhibition of cell wall synthesis
agents allow membrane of the affected microbe to rupture and release cell contents
disrpution of cell membrane function
dissolves membrane or interferes w/ movement of substances in/out of cell
inhibition of protein synthesis
agent prevents growth by disrupting the ribosomes
inhibition of nucleic acid synthesis
agent interferes with DNA replication, may disrupt info on DNA
action as antimetabolites
create competiton w/ enzymes or might be incorporated in the DNA
side effects of antimicrobials
toxicity- some exert toxic effects on patients; allergy- reaction, body reacts to agents; disruption of normal microflora- kills natural body microflora, result in super infection allows bad microbes to enter
resistance of microorganisms
no longer suseptable to grow
how resistance is acquired
over usage of drug or not take whole dose
mechanisms of resistance
alteration of targets- affect ribosomes; alteration of membrane permiability- antibiotic can't go through cell; development of enzymes- may inactivate antibiotic; alteration of enzymes; alteration of metabolic reaction
first-line, second line, third line drugs
drugs used everytime; no longer effective; move to second line, etc.; 1st-sulfonamides, 2 penicillin, 3 spectinomycin
resistant to 2 or more similar antimicrobial agents
limiting drug resistance
finish prescription; take 2 antibiotics at same time; take when necessary
disk diffusion method
disk w/ antimicrobial tested on agar plate
dilution method
serial dilution; 1 ml to 9 ml= 1:10; how little of agent needed to kill bacteria
serum killing power
obtain blood sample while patient on antibiotics; add bacterial to blood sample to see what happens
automated methods
using machinery to determine if antimicrobial will kill microbe; incubation chamber; recorded by computer
solubility in body fluids
dissolve in body fluid to transport throughout body
selective toxicity
agent must be more toxic to mo than to host
toxicity not easily altered
maintain standard toxicity; no change in interaction w/ foods
not elicit allergic reaction
get up to level in body and stay at that level; no degrade
few mo resistant to agent
long shelf life
keep therapeutic properties overtime
reasonable cost
affortable to patient
attributes of an ideal antimicrobial agent
solubility in body fluids, selective toxicity, toxicity not easily altered, nonallergenic, stability, resistance, long shelf life, reasonable cost
inhibitors of cell wall synthesis
penicillin, cephalosporins, other agents that act on cell walls
made from mold; rapidly absorbed by blood, reaches max concentration rapidly; TREAT: Gram + rods, strep, pneumonia
keflex; TREAT: Gram + rods
other agents that act on cell wall
carbapenems- new antibiotic, can be toxic; bacitracin- TREAT: Gram + rods
disrupters of cell membranes
polymyxins- can cause kidney damage, respiratory arrest; treat: skin infections, topical agents; TREAT: Gram -
inhibitors of protein synthesis
aminglycosides; tetracyclines; chloramphenicol
strepomyosin- broad spectrum antibiotic; SIDE EFFECTS: damage kidney, inner ear infections; permanent ringing of ears
not for pregnant women, cause birth defects; not for children <5, affect teeth; TREAT: acne, chlamydia, fungal infections
banned in US 1997; cause bone marrow damage, blindness; use in lanbs for gene marking and cloning
affect protein synthesis; erythromycin, zithromax, bioxin; TREAT: strep, chlamydia, legine aires disease; least toxic of antibiotics
affects protein synthesis; semi-synthetic drug; not any better than others; organisms form resistance
inhibitors of nucleic acid synthesis
rifampin- blocks RNA synthesis; TREAT: tuberculosis; quinolones- synthetic, new, ciproflaxin; TREAT: anthrax, Gram+/Gram-
sulfa group; cause kidney damage, skin rashes; TREAT: meningitis, UTI; toxic to bone marrow
give dietary supplements; mess w/ absorption in digestive tract; TREAT: tuberculosis
kills certain strains of mycobacteria; new drug
synthesized; TREAT: urinary infections
antifungal agents
imidazoles and triazoles; polyenes; griseofulvin
imidazoles and triazoles
topical creams; skin infections, candida, thrush, under nails, those cause yeast infections
amphotericin B- used for years for fungi infections; side effects- fever, chill, kidney; not used as much; nystatin- oral; TREAT: yeast infection
derived for superficial fungal infections; not absorbed well in intestinal tract; orally then sweat out; few side effects; for hair, nail skin
other antifungal agents
synthetic drugs- tinactin, lamisil; few side effects- drying of area
antiviral agents
pruine and pyrimidine analogs, amantadine, treatment of AIDS, interferons and immunoenhancers
purine and pyrimidine analogs
acyclovir and zovarax- oral/topical, reduce pain; TREAT: herpes virus
prevents influenza A; use fews days before to week after exposure
treatment of AIDS
treatments; NO CURE
interferons and immunoenhancers
we produce our own proteins; WARTS
antiprotozoan agents
quinine- from bark of tree, TREAT: malaria; chloroquine and primaquine- messes w/ protein synthesis, TREAT: malaria; metroidazole- breakage to DNA, cause black tongue, TREAT: trichomonas (STD)-gym shower, giardia- drink "clean" water that is not clean
antihelminthic agent
pesticides; niciosamide, mebendazole
inactivates products made by worm itself; TREAT: tapeworm infections
not for pregnant women- damage to fetus; TREAT: whip/pin/hook worms
other antihelminthic agents
roundworms, ascaris
special problems w/ drug resistant hospital infections
they mutate