Lecture 20 Flashcards
What is the spectrum of tetracyclins?
They are broad spectrum bacteriostatics
What bacteria are tetracyclines active against?
They are the gold standard against Chlamydia and also have good activity against Mycoplasma and Rickettsia
What should be avoided when giving tetracyclins?
Tetracyclins can bind to calcium and hence we should try and avoid giving calcium at the time of oral drug administration
How should tetracyclin injections be given for horses and ruminants?
The injections should be given parenterally for horses and ruminants due to severe GIT flora disturbances when given PO. Horses are more susceptible than ruminants.
What is the distribution of tetracyclins?
tetracyclins have good distribution
What is a potential side effect of tetracycline?
Chelation with cations (especially calcium) can result in drug accumulation in areas of high calcium and tetracyclines can absorb UV light. Can result in the irreversible discoloration or staining of teeth
What is a positive of Doxycycline?
Safest of the tetracyclines. Excreted in GIT as an inactive form more so than other tetracyclins
Are the macrolides bacteriostatic or bactericidal?
The macrolides are bacteriostatic, however they are time dependant bactericidal against some bacteria
What types of bacteria are the macrolides effective against?
mainly effective against the gram +ves and also a select few gram -ves. They have moderate to excellent anaerobic coverage.
Where do macrolides preferentially distribute to within the body?
get trapped in acidic environments. e.g abscesses, necrotic tissue, lungs, mastitis, metritis
What types of conditions is tylosin good for treating?
Footrot, mastitis and respiratory diseases and it concentrates in the milk
How should tilmicosin be administered and what species should it be avoided in?
Should only be given SC (should never be given IV or IM). It should not be used in dairy cows
What is tulathromycin registered for?
It is registered only for respiratory disease and has a 12 week dosing interval
What is the toxicity of the macrolides?
In animals very little toxicity has been reported when these drugs. The exception is with macrolides and adult horses =, they lead to GIT dysbiosis and then colitis. They should be avoided in small herbivores (especially the oral preparations) due to affects on normal anaerobic flora (beta-lactams)
Is choloramphenicol a bacteriostatic?
yes
