Antibiotics Flashcards
Name the antibiotics that work on the peptidoglycan wall:
Beta Lactams
Glycopeptides
Name the antibiotics that work in proteins/ ribosomes:
50S -
- Macrolides
- Clindymicin
- chlorpenical
30S
- Aminoglycosides
- tetracyclines
What drugs contraindicated with statins, because they increase the blood levels of the statin? and what enzyme do they block?
Macrolides
Block the enzyme CYP3A4 which breaks down statins
What drug is highly associated with ototoxicity?
Gentamicin
(macrolides also cause it but not as severely or as commonly)
**need to ask a patient every 3 days how their hearing is.
Which drug is used in high concentrations then deep troughs, due to its double effect on bacteria: initially killing cell wall, then working on the proteins?
Gentamicin
Which Drugs increase the QT interval?
Quinolines
Macrolides
What drug increase serum K+ levels, and why?
Trimethoprim
acts as a K+ sparring diuretic
What drug is used for anaerobic organisms and kills them via oxidative stress?
Metronidazole
What are the two Beta Lactamases used, and what are their combinations?
- Co-amoxiclav
- Clavulanic acid
- amoxicillin
- Tazocin
- Tazobactam
- Piperacillin
What is the first choice for serious Strep infections?
benzylpenicillin
What Beta lactam targets both Strep and Staph (not MRSA)?
Flucloxacillin
What Beta lactam has acitivity against almost all bacteria but MRSA?
Meropenem
What drug is highly associated with nephrotoxicity?
Vancomycin
What drugs are typically used for upper respiratory tract infections?
Macrolides
- clarithromycin
What drugs are useful for targeting the atypicals?
Macrolides
What drugs have excellent endotoxin neutralisation? and what are they not good against?
Clindamycin
No affect on:
- Aerobic gram negative
- Atypicals
What drug can cause bone marrow suppression? leading to aplastic anemia
Chloramphenicol
What drug causes increased action of CYP450 enzymes?
Rifampicin
When is trimethprim used?
Uncomplicated UTIs
What drug is used really only for Gram negative bacteria?
Gentamcin
What antibitics are heavily associated with causing C.Diff?
Ciprofloxacin (all quinolones)
Clindamycin
Cephalosporins
Co-amociclav
List some key ways bacteria develop resistance:
- producing enzymes that destroy the drug
- Modification to the drug target
- 23S rubunits - Decreased permeability
- down regulation of porins - Exporters to push drug out of the cell
How do these mutations of resistance come about?
- Chromosomal Mutations
- Acquisition of genetic information
- Transformation
- Transduciton
Whats the three main ways bacteria acquire new genetic information?
- Transduciton
- bacterial phages - Conjugation
- mating - Transformation
- destruction of the bacteria and spreading of information
In order to become resistant bacteria will often give up its speed of growth. what is this referred to as?
Fitness cost
What gene is associated with MRSA being resistant?
MecA
Where are the genetic codes for Beta lactamases usually found?
Plasmids
How do beta lactamases work?
Hydrolyse the Beta lactam ring
What drugs can be used in the treatment of extended spectrum beta lactamases?
Ciprofloxacin
Temocillin
Gentamicin
Meropenem
There are some bacteria that are now resistant to carbapenems, what are these called and what is the gene associated with them?
Carbapenemases
NDM-1
What bacteria is especially good at drug resistance by increasing efflux pumps?
Pseudomonas Aeruginosa
What non- genetic factors can seriously inhibit the functioning of antibiotics?
Abscess formation
Biofilm
Foriegn bodies
Slowly/ non replicating bacteria
In Sepsis what is the standard set of antibiotic treatment?
- Iv Amoxicillin 2g/6hrly
+
Gentamicin
+/- flucloaxacillin is Staph is suspected
if allergic to penicillin or MRSA then:
*IV vancomycin
+
Gentamicin
if severe Strep infection then:
+ IV clindamycin 600mg/6 hrly
What are the antibiotic treatments for Nectrotizing facititis?
Flucloxacillin
Benzylpenicillin
Gentamicin
Metronidazole
Clindamycin
Which antibiotic stops the oral contraceptive working?
Rifampcin
What must one always think about before prescribing empirical antibiotics:
- previous antibiotic treatment
- Previous microbiology culture tests - thinking about resistance
- drug allergies
- travel history - some places of travel have higher incidences of resistance than others.
If you have an organisms which is resistant to beta lactams , co - amoxiclav, cephalosporins (very wide spectrum of beta lactams) what is it said to be?
What bacteria typically call this? and what is the problem with this?
Extended spectrum Beta Lactamase
- hydrolyse the beta lactams ring
**E. Coli. they often also have resistance to gentamicin
What would be used to treat ESBL organisms?
Meropenam
What do quinolones target as their mode of action?
DNA gyrase of the bacteria
Name two sets of bacterial-static antibiotics:
Macrolides
Tetracyclines
Name the 30S inhibitors:
Aminoglycosides
- gentamicin
Tetracyclines
- doxycycline
Nitrofurantoin
Whats a common cause of resistance to gentamicin?
plasmid encoded enyzmes
What’s a common cause of resistance to tetracyclines?
Up regulation of efflux pumps
What’s a common cause of resistance to Penicillins?
Change in the PBP
Is conjugation common?
Yes
Which class of bacteria most typically produce beta lactamases?
E.Coli
Which drug may red Man syndrome be seen in?
Vancomycin
What does OHPAT stand for?
Outpatient and Home parental antibiotic therapy
When would Clindmycin be used in S. Aureus infection?
To neutralise Exotoxins when there is toxic shock syndrome
Out with exotoxins, what other class of bacteria is clindmycin good at destroying?
Anaerobics
this is why it is so effective at killing G.I bacteria leading to C. Diff infections
When would you avoid use of nitrofutoin?
In poor renal clearance
What antibiotic therapy is given for biliary sepsis?
Gentamcin - gram negatives
Amoxicillin - enterococci
Metranidazole - anaoerobics
Which antibiotics can’t be used during pregnancy?
Trimethoprime
- first trimester
Tetracyclines
Quinolones
How many days can gentamicin be used for?
up 4 days
What antibiotic is heavily associated with Steven’s JOhnson syndrome and toxic epidermal necrolysis?
Co - Trimoxazole
- trimethoprim
- sulphamethaxole
What beta lactam can be used when there is a pencillin allergy?
Monobactams
- Aztreonam
When there is an invasive Strep Pyogenes what antibiotic should be used?
Clindamycin
What drug is quinolones combined with that increases the risk of tendon rupture?
Prednisolone
What should tetracyclines not be given with?
Milk
How does nitrofurantoin work?
Increases metabolite damage of DNA
