12

antibiotics (Subject) / Phenicols (Lesson)

...

This lesson was created by eysnirmgard.

Learn lesson

back  |  next 1 / 1

Advertisement
  • active substances - Chloramphenicol - Florfenicol - Tiamphenicol
  • structure one of the most lipophilic antibiotics + small molecules -> best pharmakokinetic profile
  • Mechanism, Mode of action Mechanism: inhibition of protein synthesis (50S) Mode: bacteriostatic 
  • Resistance not so common, because they're not frequently used degrading enzymes (Acetyltransferase) ab ovo: Pseudomonas
  • microbial spectrum very broad Gr+ Gr- Mycoplasma, Chlamydophile, Rickettsia Aeromonas salmonicida, Vibrio anguilarrum in fish -> Florfenicol 
  • absorption excellent (even better than in long-acting Tetracyclines) 80-100% bioavailability can also penetrate the eye -> Chloramphenicol
  • distribution excellent - penetrate all special barriers - reach IC - penetrate into the eye -> Chloramphenicol
  • metabolism very lipophilic -> extensively metabolised in liver (contraindicated in liver failure)
  • excretion active form mainly via bile inactive metabolites via urine -> no high concentrations -> not very effective in UTI half-life depends on species: ru > su > fe > ca
  • indications primarily used in food-producing animals: florfenicol -> not for milk-producing animals, because BMB is passed and milk elimination is slow - respiratory infections (Mycoplasma and Fastidious very susceptible) - Foot diseases (anaerobs) - infectious KCS (Moraxella bovis) (if Tetracyclines can't be used) - Aeromonas infection in fish small animals: only Chloramphenicol - eye infections - prostatitis, meningitis - MRSA, MRSP - otitis externa (Florfenicol as ear drops)
  • Advertisement
  • side effects protein-synthesis-inhibition -> Bone-marrow suppression -> Anaemia: - Florfenicol: dose-dependent -> don't use in liver-failure patients -> accumulation - Chloramphenicol: dose-independent -> strictly forbidden in food-producing animals bone marrow suppression -> Leukocytopenia -> Immunosuppression: in long-term use of Florfenicol -> forbidden during Vaccination (efficacy would be decreased) pain at site of injection
  • Florfenicol dose cattle: IM 40 mg/kg ADT swine: IM 30 mg/kg ADT poultry: PO 20 mg/kg SID

back  |  next 1 / 1