Anti microbial - general principles of clinical usage and role of laboratory Flashcards
What are the four patient characteristics that have to be taken into account when prescribing antibiotics
Age
Renal function
Liver function
Pregnancy
When should Antimicrobial be administrated
for prophylaxis and therapy
When can prophylaxis be used clinically
when patient is exposed to other patients with high highly communicable disease
patient is subjected to surgical procedures
what is prophylaxis
the administration of antimicrobials to prevent future occurrence in infection
What is combination therapy and why is it useful
Cover mixed infections by more than one organism -
Benefits - can sometime enhance the effect and minimise development of resistance to any one agent
What are the possible outcomes of combined antimicrobials
effects are addictive
antagonistic - combine effect is less
synergists - combined effect is greater
How do penicillin and gentamicin acts as synergists in the treatment of streptococcal infection
penicillin breaks down streptococcal wall allowing gentamicin access to ribosomes (gentamicin usually impermeable)
What combination can make drugs addictive and a synergist
Two bactericidal or two bacteriostatic
What does the combination of one bacteriostatic and one bactericidal drug leads to what effect of the drug
antagonism
What are examples of bacteriostatic drugs
macrolides,
tertracyclines
trimethoprim
For a antimicrobial to have clinical use what must it be able to do
penetrate site of infection
What do vancomysin and gentamysin both have
low therapeutic index
What are the two reasons for monitoring serum levels
ensure therapeutic levels have been achieved
ensure levels aren’t toxic
How is vancomycin serum levels measured
By measuring a trough level immediately before does is given
How is the antimicrobial sensitivity tested
automated method- Growth of individual is measured in the presence of different concentrations of each antibiotic and the likely MIC (i.e. when bacteria growth is inhibited) of the antibiotic for that organism is calculated
