L14 - Antibacterial chemotherapy I Flashcards
Define antibiotics?
natural substances produced by one micro-organism that kill or inhibit the growth of another
Define antibacterial agents?
compounds capable of killing or inhibiting growth of bacteria, including semi -synthetic
Define antibacterial drugs?
compounds that show selective toxicity against bacterial cells v mammalian cells
Define antibacterial chemotherapy?
the use of antibacterial drugs to treat and cure bacterial infections of animals and humans
Original uses of antibiotics to the organisms they came from?
kill competing organisms
signalling molecules
3 reasons why antibacterial chemotherapy is very important?
modern medicine relies on antibiotics
massive benefits to individual health & societies
Modern economies underpinned by antibiotics
When is prophylaxis used?
ahead of invasive procedures
for decolonisation
to prevent recurrent infection
What percentage of antibiotics prescribed are not needed/inappropriate?
50%
What are uncomplicated infections?
general practice
drug chose on physical examination/patient history
empiric “best-guess” therapy
What are complicated infections?
hospitalised
start with empiric therapy - then refine drug after laboratory diagnosis and determination of susceptibility (DE-ESCALATION)
Types of antibacterial susceptibility testing?
Disk Diffusion Assay
Etest - MIC
Broth/agar dilution
Factors that influence the choice of antibacterial drugs?
antibacterial properties
plasma concentration & half life
Tissue distribution & conc. at site of infection
Dosing forms
adverse side effects & interactions
What are pharmacokinetics (PK)?
What body does to the drug
What are pharmacodynamics (PD)?
What drug does to bacterium
What is a key pharmacokinetic consideration?
availability/concentration at certain sites e.g. CSF, Urine
