Principles Of Antimicrobial Therapy Flashcards
What are the mechanisms of antimicrobial action❓
Inhibition of cell wall synthesis
Inhibition of protein synthesis
Inhibition of metabolism/nucleic acid function or synthesis
Alteration in permeability of cell membrane or active transport
Mention a few drugs that work by inhibiting cell wall synthesis of microorganisms
Beta-lactams
Vancomycin
Mention a few drugs that work by inhibiting protein synthesis of microorganisms
Aminoglycosides
Tetracyclines
Macrolides
Chloramphenicol
Lincomycins
Mention a few drugs that work by altering the permeability of cell membrane/active transport of microorganisms
Amphotericin B
Polymyxins
Mention a few drugs that work by altering the metabolism/nucleic acid function or synthesis
Sulphonamide
Trimethoprim
Pyrimethamine
Quinolone
Rifampin
What is the mechanism of resistance to antimicrobial agents❓
Spontaneous mutations of DNA ⬇️ DNA transfer of drug resistance ⬇️ Modification of target sites ⬇️ Decreased accumulation ⬇️ Enzymatic inactivation
What are the complications of antimicrobial therapy❓
Hypersensitivity
Toxicity
Superinfections
What does it mean to treat a patient “empirically”❓
What is a definitive therapy❓
What is a prophylactic therapy❓
1.
•Initiation of Rx with broad spectrum antibiotics
•Based on inference from clinical presentation, not tests
2.
•Rx initiated after lab test has identified causative organism
3.
•Rx used to prevent acquisition or establishment of pathogenic organism
What could result from excessive and indiscriminate use of antibiotics❓
⬆️Toxicity
Antimicrobial resistance
Antibiotic-induced infections
⬆️Costs
List the antibiotic-induced infections that could result from excessive and indiscriminate use of antibiotics
Clostridium difficile
MRSA Methicillin resistance staphylococcus aureus
VRE Vancomycin resistant Enterococcus
What are those drug factors to consider before administration of an antimicrobial agent❓
- Cost and availability
- Route of administration
- Drug interactions
- Spectrum of activity
- Quality control
- Mode of action “cidal/static”
What are those host/patient factors to consider before administration of an antimicrobial agent❓
Age
Organ of elimination (adrenal insufficiency)
Patient status (pregnant/lactating/immuno-comprised)
Site of infection
Hypersensitivity
Nature of infection (acute/chronic/mild (oral) /severe (IV)
What are the steps in antibiotic selection consideration❓
- Efficacy
- Toxicity
- Adherence
- Spectrum
- Risk of resistance
- Cost
Patients should not remain on broad spectrum antibiotics >48hours of drug administration
True or false❓
Why❓
True
Risk of secondary infection eg Clostridium difficile
Risk of line associated w soft tissue infection eg bacteraemia or endocarditis
What are the conditions in which a switch from IV to oral antibiotic is appropriate❓
Simple UTI Exacerbated COPI Community acquired pneumonia Skin/soft tissue infection Pyelonephritis
