Macrolides Flashcards
Bacteriostatic or bacteriocidal?
Bacteriostatic but are bactericidal at high concentration
MOA?
Inhibits protein synthesis by reversibly binding to 50S subunit of the bacterial ribosome
What type of drugs does it interfere with?
Interferes with Chloramphenicol binding (competitive antagonism)
What cells do they tend to accumulate in?
Leukocytes and are transported into the site of infection
Spectrum of action?
Narrow: G(+) e.g Pneumococci, strep and staph
What tier?
Tier-2
Which drugs in this group arent tier-2?
Tylosine, Tilmicosin and Erythromycin (large animals and poultry)
Indications?
For resistant bacteria in pneumonia, footrot, mastitis
Resistance?
Most other G(-) anaerobes and Enterobacteriaceae are resistant
What is the Distribution and Excretion?
D - well in most tissues except CSF and tend to concentrate in certain cells notably the lungs
What types of infections is this drug ideal for?
Respiratory tract infections
Adverse effects?
Muscle paralysis with some anaesthetics Non-fatal diarrhoea in horses Altered temp homeostasis - hyperthermia Cardiac effect (horses, pigs and primates) IM injections are painful
What are some drugs in this category?
Erythromycin, Azithromycin, Clarithromycin, Tylosin, Tilmicosin
What are some important absorption considerations for Erythromycin?
They are destroyed by stomach acid and absorption is inhibited by food
What are some important adverse effects for Erythromycin?
Causes GI upset (motilin agonist even at low doses) may cause nausea and vomiting following oral admin (dogs)
