Antibacterials Flashcards
What does murpirocin treat?
staph and strep skin infections and MRSA
Is murpirocin bacteriocidal or static
Static
What acronym is used to remember all antibacterials
MOTMAFc
What is murpirocin specific for and what does this result in
inhibiting isoleucin and t-RNA synthetase, causing raw materials for proteinsynthesis to not be produced
Is murpirocin broad or narrow spectrum
Narrow
Why can’t murpirocin be used systemically
because it is de-esterfied in the kidney and liver producing metabolites that lack antibiotic activity
What are two examples of Oxazolidinones
Linezolid and Tedzollid
How is murpirocin given
topically
What are the two oxazolidinones used to treat and how are they given
pneumonia and skin infections, given by oral or IV
what effect does the oxazolidinones Linezolid have on blood
Thrombocytopenia - fall in blood platelet count
Anaemia - fall in haemoglobin
why is tedzolid more useful than linezolid
It has increased antibacterial potency
Are the Tetracyclines broad or narrow spectrum
Broad
How are Tetracyclines given
oral
What in the body can Tetracycline affect (3 things)
- photosensitivity
- CNS
- growth (not given to children or late pregnant women)
How does Tetracycline work?
It prevents association of amino-acyl-tRNA with the ribosome
What is used instead of Tetracycline because of resistance?
Tigecycline (only IV)
Are Aminoglycosides bactericidal or static
Cidal
How do the aminoglycosides work
they interfere with the proof reading mechanism of proteins resulting in proteins not being able to fold and hydrophilic regions being buried
What is mono therapy of aminoglycosides used to treat
sepsis, plague, enterococcal endocartis
What is combo therapy of aminoglycosides used to treat
TB
What toxicity issue can combo therapy of aminoglycosides cause, 3 things
Ototoxicity (permanent), hearing and balance issue
Nephrotoxicity
Neuromuscular blockade
What antibiotic works by blocking the exit of 50s ribosomes?
Macrolides
What does blocking of the exit of 50s ribosomes by Macrolides cause?
Growing peptides cannot leave, causing premature dissociation of peptidyl-tRNA
How are macrolides given
ORal or IV
What is the most important Macrolide
Azalide
What may Macrolides be used to treat
Chlamydia and Syphilis
How does Fusidic acid work
Inteferes with G elongation factor, responsible for mediating translocation of ribosomes from one codon to the next. The acceptor site is blocked once the drug becoems bound to EGF
How can Fusidic acid be given
Oral, IV or Topical
What side effects are experienced using Fusidic acid
Rash or jaundice
What is Chloramphenicol used to treat
Typhoid fever
What toxicity issues are experienced using Chloramphenicol
Myelosupression - aplastic anaemia
Gray syndrome - lack of red or white blood cells
How does chloramphenicol work
Binds to large subunit of 50s affecting catalytic activity and inhibition of peptidyl transferase activity
