general principles of clinical usage Flashcards
What patient characteristics must be considered when choosing an agent and why?
- age - certain drugs not advised for children
- renal function - many antimicrobials excreted in kidneys so accumulate in body if renal failure
- liver function - antimicrobials may be metabolised by liver
- pregnancy - some antimicrobials are thought to be mutagenic (induce mutation in foetal characteristics), teratogenic (associated with congenital abnormalities) or both
What is prophylaxis?
the administration of antimicrobials to prevent the future occurrence of infections
What type of antimicrobial therapy should be commenced if urgent treatment is required and the organism causing the infection is unknown?
empirical antimicrobial therapy
*should always be reviewed once results of culture and antibiotic sensitivity tests become available
Why should vancomycin and gentamicin levels be monitored?
to avoid toxicity
In what three circumstances may antimicrobials be used in combination?
- to cover mixed infection by more than one organism
- because two antimicrobials sometimes have an enhanced effect together
- to minimise development of resistant strains to any one agent
What are the three possible outcomes when antimicrobials are used in combination?
- their effects are addictive
- they are antagonistic and combined effect is less than sum of individual contributions
- they are synergistic and their combined effect is greater than the sum of their individual characteristics
as a general rule what is the combination of two cidal drugs or two static drugs?
addictive or synergistic
as a general rule what the combination of one static drug and one cidal drug?
antagonistic
is it important the antimicrobial can penetrate the site of infection?
YES
what is the standard course of therapy for many infections?
7 days
