Lecture 6 - general principles of treatment Flashcards
Difference between primary and secondary prophylaxis ?
1 - prevent initial infection
2- prevent recurrent episodes
Name the five questions asked in accurate diagnosis of an infection
1- infection? 2- source? 3- microorganism? 4- need antibiotics or self limiting? 5- urgent or can diagnosis me made?
If a positive culture has been identified, when would you not start antibiotics ?
if culture is from a non sterile sit e.g. wounds
could just be colonisation
When would you use a broad spectrum antibiotic (2) what is the risk (1)
when microbiology is uncertain or infection is caused by a mixture of organisms. promotes resistance
What 5 things must you consider when evaluating if the drug is safe to give a particular patient
1) does the patient have impaired excretion
2) any drug interactions with preexisting prescriptions
3) is there a high risk of toxic effect e.g. CNS toxicity in epileptic, BM toxicity in transplant patients
4) does the patient have a known hypersensitivity?
5) is there a risk of Abx associated diarrhoea
When would a bacteriostatic antibiotic be effective?
if the toxin is the main pathogenic agent, bacertiocidal drugs would cause lysing of cells and therefor release more toxins
Name three situations when bacteriocidal drugs are preferred
the immunocompromosed (ill or stedoid therapy) the immunodeficient (neutropenia or HIV) difficult sites (meningitis or endocarditis)
Name some positives of changing from iv to oral antibiotics
reduces potential of line infection saves nursing time reduces patient discomfort reduces treatment costs reduce risk of adverse effects
What is the criteria for changing from iv to oral antibiotics
Clinical improvement observes
Oral route is not compromised
Markers showing trend towards normalising
Specific indication/ deep seated infection
How long should most infections take to respond to treatment?
5-7 days according to severity of condition
What is outpatient parenteral antibicrobial therapy and when is it appropriate?
iv at home - long term semi-permanent line and self administered. used in long term treatment to reduce hospital bed days and less hospital acquired infections
Give three reasons why combination therapy would be more effective than monotherapy
broader spectrum cover
prevent resistance e.g. tb
synergistic e.g. penicillin and gentamicin
State two negatives to combination therapy
increase costs and increased risks of toxicity
When is it appropriate to give oral vancomycin and not systemic
with infections in the gut e.g. cdiff. dont use oral for systemic infections as wont work - use iv
Name 4 situations that may need extra considerations when prescribing
pregnancy
lactation
newborn
old age