Phenicols Flashcards
What are the phenicols?
Chloramphenicol
Florfenicol
Can you use chloramphenicol in horses? Cattle?
Yes
NO FOOD ANIMALS EVER
Are phenicols water or lipid soluble? What is the Vd?
Lipid soluble
Very high Vd
Chloramphenicol is the parent of? Which is the parent of?
Thiamphenicol
Florfenicol
What is the MA of phenicols?
Protein synthesis inhibition
Why must chloramphenicol be carefully used in human and veterinary medicine?
Aplastic anemia by inhibiting protein synthesis in bone marrow
Is aplastic anemia dose related?
Yes except 1 in 25k people will die due to fatal aplastic anemia & is not dose related
Why should use give patients gloves with chloramphenicol?
Liability
Why can you not use chloramphenicol in food animals?
Aplastic anemia in people
What is the spectrum of phenicols?
Anaerobe: +++++
Gram + Aerobe: +++++
Gram - Aerobe: ++
Are phenicols effective against pseudomonas?
Not anymore (resistance)
What are some advantages of florfenicol vs chloramphenicol?
Greater in vitro potency against most pathogenic organisms. Activity against Salmonella typhimurium, Staphylococcus aureus
What is florfenicols relation to BRD?
Active against M. haemolytica, P. multocida, H. somni
Which unique organisms are resistant to phenicols? Which unique organism is susceptible?
Mycobacterium, Nocardia
Leptospira is susceptible
Which routes of administration are available for Chloramphenicol?
Oral tablets/capsules
Powder for injection
Which routes of administration are available for florfenicol?
IM/SC injectable for cattle
Oral for swine
What is the route of elimination of phenicols?
Hepatic via conjugation with glucuronic acid
Why are elimination times longer in fetuses and neonates?
Deficient in glucuronyl transferase activity
Why must you be careful when administering chloramphenicol to a dog on phenobarbital?
Choramphenicol reduces glucuronide conjugation and oxidative pathways in liver which reduces hepatic clearance of phenobarbital. Dog will be comatose!
What is efficacy of chloramphenicol dependent on?
Time above MIC
What is a concern in patients with renal or liver disease?
Accumulation of chloramphenicol
What is grey baby syndrome? Which species are we particularly worried about?
Circulatory collapse due to inability to conjugate or excrete conjugate.
Kittens
Will chloramphenicol interfere with vaccine response from distemper vaccine? Why would it?
No
Immune suppression via bone marrow inhibition
In vitro studies have shown decreased phagocytosis of what bacterial species when chloramphenicol is administered?
Staph aureus
