53. Polypeptide antibiotics, rifampicin Flashcards
(20 cards)
What are Polypeptide antibiotics?
Polypeptide antibiotics are a class of antibiotics that prevent bacterial infections by preventing or disrupting the formation of the bacteria’s cell wall.
Polypeptide antibiotics, Active substances
- Bacitracin
- Polymyxin B
- Polymyxin E (Colistin)
Bacitracin, mechanism of action:
Bacitracin works by preventing bacteria from forming the outer cell wall
Bacitracin, Mode of action:
Bactericidal
Kills the bacteria
Bacitracin, AB spectrum:
Bacictracin, Pharmacokinetics:
Not absorbed PO
the drug will enter the bloodstream
Bacictracin, Toxicity:
Highly toxic ⭢ Topical or oral only !!!
Not irritant
Bacictracin, Indications:
- Topically for the eye or ear
- ERE orally - ⭢ Rabbit enzootic enteropathy
Polymoxins, mehcanism of action:
Destruction of the cell outer and inner membrane
Polymoxins, mode of action:
Destruction of the cell outer and inner membrane
Bactericidal
Polymoxins, pharmacokinetics:
Not absorbed PO
Tissue debris will decrease the activity
Polymoxins, AB spectrum:
Polymoxins, toxicity:
Highly toxic when given locally and PO
There are injections available in case of colistimethate
Polymoxins, indications:
- Enteritis and mastitis caused by Gram-
- Otitis locally
What are Rifampicin?
They are antibiotics that work by suppressing the bacteria’s production of genetic material. As a result, the bacteria die.
They belong to Rifamiycins
Rifampicin, Active substances:
- Rifampin (rifampicin)
- rifaximin
Rifampicin, mode of action:
Concentration dependent bactericidal
Rifampicin, AB spectrum:
Rifampicin, pharmacokinetics:
1. Absorption
Good oral absorption
2. Distribution
Excellent
3. Metabolsim
CYP 450 enxyme
4. Elimination
Bile and urine
Rifampicin, indications:
- MRSA infections in companion animals
- R. Equi in horses as combination
