Flashcards in Antibiotics Deck (56)
Saving commensals and overall population susceptibility (Bacterial Refugia) is achieved by what treatment approach
What is one of the best treatment approaches on finding an increase in fibrinogen, white cell count and presence on phagocytosed bacteria on microscopy?
Combination showing synergism/appropriate broad spectrum
Explain antibiotic combination antagonism
Static + cidal
For how long should antibiotic therapy be continued after the clinical symptoms disappear?
Name one factor that may increase the necessity of antibiotic use during surgical procedures.
How does polar antibiotics (water soluble) antibiotics cross cell membranes?
Define Area Under the curve (AUC)
Amount of absorbed drug in blood stream
What is the half life of a drug?
Time to half concentration
Explain the mechanism of time dependent antibiotics.
Time above MIC 40-70%. Average of 50%
Name 1 factor which will influence the volume of distribution of an antibiotic.
Protein binding/charge/ size/ pH
How can the amount of free antibiotic in the blood be increased
Amount of drug in blood measured by AUC
Name 3 factors that will influence bioavailability.
Dose, Injection site and volume
Define Volume of distribution.
(Total dose-bioavailability) – blood concentration= Vd example. Inject 100mg absorbed 60%. Total amount in body 60mg Blood concentration 20mg 60/20 = 3L/KG
Which group of antibiotics generally have a large volume of distribution?
What are the rules regarding ELDU in pet animals?
Does not apply. Need confirmation animal wont enter food chain.
Which are the major food producing species?
Where is the best location to give a sc injection in a small ruminant?
What is a side effect giving propylene glycol intravenously?
Lower blood pressure
Give an example of a time dependent antibiotic.
Give an example of an concentration dependent antibiotic.
Fluroquinolones. Depend on concentration. Does not equate to multiple dosing because of post antibiotic effect
AUC of penicillin would be affected if which organ fails?
What is the spectrum of penicillin?
Gram positive anerobe
Why is penicillin commonly used for the following wound infections, black leg and listeria?
In which production animals is the use of penicillin prohibited?
Lactating dairy cows and veal calves
You have a animal with a lymph adenopathy. There are phagocytosed bacteria in the lymphocytes. Culture show susceptibility to both procaine penicillin and Tulathromycin (macrolide). Which of the 2 antibiotics would you choose as a initial treatment and why?
Penicillin. Bactericidal preferred over intracellular
You have 2 antibiotics. One has a Vd of 10l/kg and the other 36L/kg which of the 2 antibiotics would you choose for a case of septic meningitis. Assume that the sensitivity of both for the infection is the same.
Vd 10L, bactericidal
Give 2 advantages of using synthetic penicillin over procaine penicillin.
Gram negative spectrum/can be used in lactating dairy cows and veal calves
Why is the meat withdrawal time for procaine penicillin problematic.
Because of variation in dose rates