Chloramphenicol & derivates Flashcards
Quiz 1
what type of antimicrobial interferes with bacterial protein synthesis ?
- Chloramphenicol & its derivatives
- Macrolides
- lincosamides
How does the antimicrobial interfere with bacterial protein synthesis ?
inhibits of 50s Ribosomal binders
what is the source for Chloramphenicol & its derivatives ?
- streptomyces venezulae
2. manufactured synthetically
What structures of chloramphenicol & its derivatives depend on efficiency of the drug?
- p-nitrophenol group
- dichloroacetyl group
- Alcoholic group
what are the general features of chloramphenicol?
- bacteriostatic
- lipid soluble , neutral compound
- antibacterial antagonism
what are the derivatives of chloramphenicol?
- Thiamphenicol
2. florfenicol
what is the mechanism of action for chloramphenicol ?
- inhibits bacterial protein synthesis
- permeate into bacteria & reversible binds to 50s ribosomal subunit
- inhibits bacterial enzyme peptide transferase
- inhibits peptide formation
What is signifiant about mammalian mitochondrial ribosome with chloramphenicol?
inhibits mammalian mitochondrial protein synthesis
What should never be done with antimicrobial the interference with bacterial protein synthesis?
combed together - antibacterial antagonism
what his the microbial susceptibility of chloramphenicol?
broad spectrum antibiotic
- gram + bacteria
- gram - bacteria
- anaerobes
- Mycoplasma , rickettsia
what are the species of gram + bacteria that can be treated with chloramphenicol ?
- staphylococci sp. ( S. aureus)
2. Streptococci (S. pyogenes)
what are the species of gram - bacteria that can be treated with chloramphenicol ?
- Escherichia coli
- bordetella bronchiseptiica
- Pasteurella sp.
- Proteus vulgaris
- Salmonella sp.
- Shigella sp.
what are the species off anaerobes that can be treated with chloramphenicol ?
- Actinomyces sp.
- clostridium sp.
- bactericides sp.
- Fusobacterium sp.
what is the pharmacokinetics of absorption for chloramphenicol ?
- highly lipid soluble
2. well absorbed in oral & parental route
What type of animal is the absorption is good & rapid ?
- monogastrics
2. preruminants
what type of animal is chloramphenicol inactive during absorption?
ruminants - ruminal microorganism
what is the pharmacokinetics of oral in chloramphenicol ?
- chloramphenicol base (unconjugated form)
2. chloramphenicol palmitate ( increase palatability)
what is pharmacokinetics of parenteral in chloramphenicol succinate ?
- hydrolyses in plasma
2. rapid & complete absorption ( IM & SC)
What type of administration for chloramphenicol ?
- oral
- IM
- SC
- IV
- otic preparation
- ophthalmic preparation
what is the pharmacokinetics of distribution of chloramphenicol ?
- plasma protein binding ( 30-50%)
- widely distributed
- attains high concentration in tissue
- high volume distribution
Where is chloramphenicol widely distributed in the body?
- placental barrier
- diffuse into milk
- eyes
- CNS
- heart
- lungs
- prostate
- salivary glands
- liver
- spleens
Which tissue contain high concentration of chloramphenicol used for treatment of infections?
- CNS
2. Respiratory tract
what are the pharmacokinetics of metabolism in chloramphenicol ?
liver
glucuronidation
what are the metabolites of chloramphenicol
- chloramphenicol glucuroniide
What does metabolism of chloramphenicol depend on ?
- age
2. species
what type of animal have slow metabolism of chloramphenicol ?
young animals
what animals are defcient in glucuronidase enzyme causing slow metabolism of chloramphenicol ?
cats
what is the pharmacokinetics of excretion of chloramphenicol ?
- urine in tubular secretion
2. bile
How are chloramphenicol excreted in bile?
glucuronide conjugate excreted in biile undergo hydrolyses into active drug
what is the adverse effect of chloramphenicol ?
- dose related reversible bone marrow suppression
2. aplastic anemia
How is chloramphenicol a dose -related reversible bone marrow suppression ?
suppression of mitochondrial protein synthesis in bone marrow cells in host
What type of animals are chloramphenicol prohibited from using ?
food producing
What was taking out of chloramphenicol & replaced with nitrosochloramphenicol ?
para-nitro group of chloramphenicol
what are the type of chloramphenicol has nitros-chloramphenicol ?
- thiamphenicol
2. florfenicol
what is significant of nitrosochloramphenicol?
can’t induce bone marrow toxicity
What type of animals are more sensitive for toxicity of chloramphenicol ?
- young animals
- cats
3 animal w/ impaired liver function
what are the clinical signs seen in adverse effects of chloramphenicol ?
- depression
- reduce fluid intake
- emesis
- diarrhea
- dehydration
- weight loss
what type of drug interaction for chloramphenicol have ?
- inhibitor of Cytochrome P-450 drug metabolizing enzyme
- competition for site of action with:
- macrolides
- chloramphenicol
- lincosamides
what are the bacterial resistance for chloramphenicol ?
acquired plasmid -mediate resistance
what is resistant to enzyme inactivation in bacterial resistance of chloramphenicol ?
florfenicol
what is the acquired , plasmid -mediated resistance of chloramphenicol ?
due to synethesis of chloramphenicol transcetylase enzyme
what is thiamphenicol of chloramphenicol derivates?
- semi- synthetic structural analog
- para-nitro group sibstituted w/ methyl sulfonyl moiety
- water soluble
- metabolized to significant extent
- excreted as active form
- mechanism of action & antibacterial spectrum