Antibiotics - Aminoglycosides Flashcards
What is transcription?
1 - copying of specific part of DNA to create mRNA
2 - converting mRNA into proteins using the ribosome
3 - adding molecules to proteins
4 - packaging proteins into vesicles
1 - copying of specific part of DNA to create mRNA
What is translation (also called protein synthesis)?
1 - copying of specific part of DNA to create mRNA
2 - converting mRNA into proteins using the ribosome
3 - adding molecules to proteins
4 - packaging proteins into vesicles
2 - converting mRNA into proteins using the ribosome
Ribosomes in prokaryotes (bacteria) is smaller in eukaryotes (human cells). Why is this important for drug development?
1 - means bacteria are limited to how they replicate
2 - drugs can inhibit mRNA
3 - drugs can be targeted against prokaryotes ribosome specifically
4 - bacterial wall production can be inhibited
3 - drugs can be targeted against prokaryotes ribosome specifically
- prokaryotes - 50 and 30S = 70S
- eukaryotes - 60 and 40S = 80S
Which of the following is NOT a step in translation (protein synthesis)?
1 - elongation
2 - transcription
3 - initiation
4 - termination
2 - transcription
Which of the following described initiation?
1 - codon signalling termination is recognised by P site
2 - 1st tRNA binds to P site and begins adding further tRNA
3 - 50S and 30S subunits bind to mRNA forming ribosome-mRNA complex
4 - tRNA bind to the A, P and E binding sites of ribosome
3 - 50S and 30S subunits bind to mRNA forming ribosome-mRNA complex
- mRNA is the blueprint for protein synthesis
- composed of 3 nucleotide sequences called codons
- tRNA binds to codons with matching anti-codon sequence
The ribosome complex has 3 specific sites where the mRNA can bind. Which of the following is NOT one of these sites?
1 - A site (aminoacyl site)
2 - B site (binding site)
3 - P site (peptidyl site)
4 - E site (exit site)
2 - B site (binding site)
- correct codons are added at sites A and P, building a protein, once finished a stop codon is recognised and the mRNA is then detached and a protein is formed.
The ribosome complex has 3 specific sites where the mRNA can bind, A site (aminoacyl site), P site (peptidyl site) and E site (exit site). Once the correct codons have been added at site A and P, the mRNA is then detached and a protein is formed.
Which of the following described elongation?
1 - codon signalling termination is recognised by P site
2 - 1st tRNA binds to P site and begins adding further tRNA at site A
3 - 50S and 30S subunits bind to mRNA forming ribosome-mRNA complex
4 - tRNA bind to the A, P and E binding sites of ribosome
2 - 1st tRNA binds to P site and begins adding further tRNA at site A
- this repeats until protein is finished
Which of the following described elongation?
1 - codon signalling termination is recognised by P site
2 - 1st tRNA binds to P site and begins adding further tRNA at site A
3 - 50S and 30S subunits bind to mRNA forming ribosome-mRNA complex
4 - tRNA bind to the A, P and E binding sites of ribosome
2 - 1st tRNA binds to P site and begins adding further tRNA at site A
- this repeats until protein is finished
Which of the following described termination?
1 - codon signalling termination is recognised by P site
2 - 1st tRNA binds to P site and begins adding further tRNA at site A
3 - 50S and 30S subunits bind to mRNA forming ribosome-mRNA complex
4 - tRNA bind to the A, P and E binding sites of ribosome
1 - codon signalling termination is recognised by P site
Which of the following is the core Aminoglycosides that we need to be aware of?
1 - Doxycycline
2 - Clarithromycin
3 - Erythromycin
4 - Gentamicin
4 - Gentamicin
Gentamicin is the core Aminoglycosides that we need to be aware of. What is the mechanism of action of this class of antibiotics?
1 - binds to penicillin binding protein
2 - interfere with NAG and NAMs
3 - bind to 50S ribosome
4 - irreversibly binds the 30S ribosome subunit and inhibits protein synthesis
4 - irreversibly binds the 30S ribosome subunit and inhibits protein synthesis
- blocks formation of the initiation complex
- miscoding of amino acids in the emerging peptide chain due to misreading of the mRNA
- blocks translocation on mRNA
Gentamicin is the core Aminoglycosides that we need to be aware of. Is this a bactericidal or bacteriostatic?
- bactericidal
Gentamicin is the core Aminoglycosides that we need to be aware of. Is this a broad or narrow spectrum antibiotic?
- broad spectrum
- main activity is on gram negative aerobic bacteria
- examples include: Klebsiella, Acinetobacter, Pseudomonas aeruginosa, and E. coli.
Gentamicin is the core Aminoglycosides that we need to be aware of. It is broad spectrum, but very affective against gram negative aerobic bacteria. It is also affective against streptococcus and anaerobes, BUT needs to be combined with which 2 other antibiotics?
1 - B-lactam antibiotics (penicillin)
2 - Quinolones (Ciprofloxacin)
3 - Metronidazole (Nitroimidazole)
4 - Glycopeptide (Vancomycin)
1 - B-lactam antibiotics (penicillin)
3 - Metronidazole (Nitroimidazole)
- helpful in breaking down cell walls and allowing Aminoglycosides access to ribosome
Gentamicin is the core Aminoglycosides and it is usually reserved for severe infection caused by Gram negative anaerobes. Of all the bacteria it can be used against, which is the most common?
1 - Klebsiella
2 - Acinetobacter
3 - Pseudomonas aeruginose
4 - E. coli.
3 - Pseudomonas aeruginose
Gentamicin is the core Aminoglycosides and it is usually reserved for severe infection caused by Gram negative anaerobes. It is indicated in all of the following EXCEPT which one?
1 - Sepsis (when source is unidentified)
2 - Clostridium difficile colitis
3 - Pyelonephritis (kidney infection) and complicated UTI
4 - Intra-abdominal infection
5 - Endocarditis
2 - Clostridium difficile colitis
- vancomycin, a Glycopeptide antibiotic is 1st line for this
What are the 2 main adverse events that can be caused by Gentamicin?
1 - nephrotoxicity
2 - ototoxicity
3 - hepatic liver failure
4 - colitis
1 - nephrotoxicity
- accumulates in tubular epithelial cells, but may be reversible
2 - ototoxicity
- accumulates cochlear and vestibular hair cells, but may be irreversible
The monitoring of gentamicin is crucial to minimise nephrotoxicity and ototoxicity. This is particularly important in which group of patients?
1 - neonates
2 - older patients
3 - renal impairments
4 - all of the above
4 - all of the above
- can be used, but needs close monitoring
Gentamicin can impair neuromuscular transmission and there should not be used in which condition?
1 - myasthenia gravis
2 - multiple sclerosis
3 - fibromyalgia
4 - vitamin B12 deficiency
1 - myasthenia gravis
The risk of nephrotoxicity and ototoxicity is increased if gentamicin is used in combination with all of the following medications, EXCEPT which one?
1 - loop diuretics
2 - glycopeptide antibiotics
3 - NSAIDS
4 - ACE-I or ARB-II
5 - cephalosporins
4 - ACE-I or ARB-II
- all other have adverse events that cause nephrotoxicity and ototoxicity
- can stop medications temporarily while giving gentamicin
How is gentamicin normally prescribed?
1 - oral
2 - IV
3 - IM
4 - suppository
2 - IV
- cannot be absorbed in the GIT as they are highly polarised
Gentamicin is normally given via IV in severe infections once a day. However, the length of time between doses is determines by which 2 of the following variables?
1 - renal function
2 - body weight
3 - hepatic function
4 - thyroid function
1 - renal function
2 - body weight
- normal is every 24h, but can be longer in renal impairment
- 1mg/mL is the normal safe plasma concentration
When prescribing any antibiotics, in accordance with antibiotic stewardship, which of the following must be document on the prescription and in the patients notes?
1 - indication
2 - review date
3 - treatment duration
4 - all of the above
4 - all of the above
If prescribed as IV, how long should it be before the antibiotics are switched to oral where appropriate?
1 - 12h
2 - 24h
3 - 48h
4 - 72h
3 - 48h
Broad spectrum antibiotics are prescribed empirically, when we do not know the specific cause of the infection. However, what is the main driver to switch antibiotics to a narrow spectrum antibiotic?
1 - cost
2 - patients request
3 - microbiology results
4 - allergies
3 - microbiology results
