Infections Flashcards
What parameters require monitoring when using aminogylcosides?
Drug-serum concentration and renal function
When should you avoid using once daily dose regimen of aminoglycosides?
Avoid in renal function <20ml/min
HACEK or gram-positive endocarditis
Burns covering >20% of body
When should blood samples be taken for multiple dosing regimen of aminoglycosides?
Post-dose (peak) concentrations 1 hour after administration
Pre-dose (trough) concentrations before administration of next dose
How to manage high post-dose serum concentration of aminoglycosides
Reduce dose
How to manage high pre-dose serum concentration of aminoglycosides
Increase interval
\Which classes of abx contain beta-lactam structure?
Pencillins
Carbapenems
Cephalosporins
Which antibiotics inhibit cell wall synthesis ?
Pencillins
Carbapenems
Cephalosporins
Glycopeptides
Give three examples of cephalosporins
Cefalexin (first-gen)
Cefuroxime (second-gen)
Cefotaxime, ceftazidime, ceftriaxone (third gen)
What is the MOA of macrolides?
Inhibit bacterial protein synthesis
Metronidazole is active against __________ bacteria
Metronidazole is active against anaerobic bacteria
Which abx should be taken on an empty stomach?
Flucloxacillin
Isoniazid
Phenoxymethylpenicillin
Ampicillin
Which abx should be taken with or just after food?
Metronidazole
Nitrofurantoin
What is the interaction between metronidazole and alcohol
Disulfram-like reaction causing flushing, SOB, throbbing headache
Avoid __________ during the course of metrondiazole and for _________ after ____________________________
Avoid alcohol during the course of metrondiazole and for 48 hours after completing the course.
Vancomycin has ____ gram __________ activity.
Vancomycin has no gram negative activity.
What class of abx can cross-react with pencillins?
First generation cephalosporins and early second generation of cephalosporins
Give examples of aminoglycosides and how are they used?
Gentamicin, amikacin, streptomycin
Poorly absorbed from the gut therefore given by injection for systemic infections (requires TDM) - except neomycin which is never given parenterally (too toxic)
How do you measure serum gentamicin concentrations?
After 3 or 4 doses of a multiple daily dose regimen, blood sample taken 1 hour after dose (peak) and just before dose (trough).
Measure serum-gentamicin conc at least every 3 days thereafter and after a dose change. More frequently in renal impairment.
What are the target concentrations of gentamicin in multiple daily dose regimens?
peak concentration should 5-10mg/L
trough concentrations should be less than 2mg/L
Same targets for children.