Antibiotics (year 2) Flashcards
what is the general mechanism of action of antimicrobial?
prevent growth/survival of invading organisms
which antimicrobials disrupt cell wall production/function? (3)
beta-lactams
penicillins
cephalosporins
which antimicrobials are DNA function inhibitors?
potentiated sulphonamides
fluoroquinalones
aminocoumarines
which antimicrobials inhibit protein synthesis?
aminoglycosides
tetracyclines
macrolides
florphenicol
which antimicrobial disrupts the cell membrane function?
ionophores
what are bacteriostatic antibiotics?
antibiotics that prevent replication of bacteria
what are bacteriocidal antibiotics?
antibiotics that kill bacteria
what do bacteriostatic drugs require to work?
good immune response from host
why should bacteriostatic and bacteriocidal drugs not be used together?
bacteriocidal drugs often require active growing cells
what are some groups of narrow spectrum antibiotics? (3)
penicillins
aminoglycosides
macrolides
what are some examples of broad spectrum antibiotics? (5)
synthetic penicillins potentiated sulphonamides cephalosporins tetracyclines fluoroquinolones
what is empiric therapy?
infected organism not identified (broad spectrum antibiotic)
what is definitive therapy?
organism identified and specific therapy chosen
what does how long we treat an animal with antibiotics depend on?
mode of action of drug
what is post-antibiotic effect?
ability of drug to suppress/kill bacteria after the drug concentration drops below the minimum inhibitory concentration
what are some examples of concentration dependant antibiotics? (3)
aminoglycosides
fluoroquinolones
metronidazole
what is meant by the term concentration dependant antibiotics?
rate and extent of bacterial killing increases as drug concentration increases
what is meant by time dependant antibiotics?
overall effect correlates strongly with the time above the minimum inhibitory concentration
what is MIC?
minimum inhibitory
what are some examples of time dependant antibiotics? (3)
penicillins
cephalosporins
macrolides
what effects the systemic availability of drugs? (4)
dose/form
route of administration
dosing rate
access to site of infection
what is the volume of distribution?
reflection of the amount of drug left in the bloodstream after the drug has been absorbed
if little drug is left in the bloodstream, how would the volume of distribution be described?
large volume of distribution
what pH do acidic drugs diffuse better into?
alkaline
at what pH do drugs getting into the tissue better than serum?
alkaline
what are examples of beta lactams? (2)
penicillins
cephalosporins
how do penicillins work?
block cell wall crosslinks, making the walls weaker
what are the classes of penicillins? (5)
natural beta lactamase resistant aminopenicillins extended agents augmented agents
where are penicillins cleared by?
kidneys
what are some side effects of penicillins?
immune mediated reactions muscle tremors ataxia hyperexcitability inhibit protein binding of other acidic drugs
