Intro To Chemotherapy Flashcards
What is empirical antimicrobial therapy?
Starting an antibiotic before the pathogen responsible for the illness is known
What is conjugation?
The cell to cell transfer of genetic material through a sex pilus
What is the drug of choice for surgical procedure prophylaxis?
Cefazolin
With bactericidal drugs, is there much of a difference between static and cidal concentrations?
No
With bacteriostatic drugs, what is the difference between inhibitory and cidal concentrations?
Inhibitory concentrations are much lower.
The cidal concentrations are too high to be safe for the patient so we give them at static concentrations
What can you do if a drug has a post antibiotic effect/>
Reduce frequency of dosing=lower risk of adverse effects
When starting empiric therapy, when should you obtain a specimen for culture?
Before starting any antibiotic
What is an example of a drug combo that achieves synergy by enhancing the uptake of the antimicrobial agent?
Penicillins increasing the uptake of aminoglycosides
Are static agents a good choice for immunocompromised patients?
Never
Does chemotherapy select for resistant strains?
Yes
What is a concern with broad-spectrum abx?
Kills normal flora = GI distress
Vertical resistance results from:?
Mutation in mother cell transferred by selection to daughter cell
What type of antibiotics most frequently cause super infections?
Broad spectrum
What is the most common superinfection?
Intestinal candidiasis
What is a drug combo that does synergy by blocking sequential steps in metabolic sequence?
TMP-SMX
What are the 2 major mechanisms of antagonism?
- ) inhibition of cidal activity by static agents
2. ) induction of enzymatic inactivation: some G- bacilli contagion inducible beta lactamases
What is synergism?
When the killing/inhibitory effects of 2 or more drugs are significantly greater than expected from their effects individually
What is MIC vs MBC/
MIC- minimum inhibitory concentration
MBC- minimum bactericidal concentration
What are 2 life-threatening superinfections?
Staphylococcal enterocolitis
Pseudomembranous colitis
(In both cases you must discontinue the antibiotic and give oral vancomycin)
What is time dependent killing?
Killing is not increased with increasing concentrations above the MBC, but is instead dependent on the time of exposure to the drug
What is meant by selective toxicity?
You need a greater toxicity to the parasite than host
What is vertical transmission of antoboiotc resistance?
Comes about through a mutation and is passed down to daughter cells
How do bacteria transmit drug resistance?
Usually through plasmids
What is concentration dependent killing?
The rate of killing is dependent upon drug concentration
