Antibiotic Classes and MOA Flashcards
What are the targets for killing a cancer cell?
DNA and Mitotic tubules
Do we want to target what we do in cancer cells when trying to kill bacteria?
NO. Because bacterial cells have things in them that our cells don’t and therefore we can target that
What are some things we target in bacterial cells?
- Cell wall synthesis
- Transcription and translation
- DNA synthesis and integrity
What do bacteriostatic drugs do?
- Inhibits cell growth, does NOT kill the cell
- They slow down the spreading of the bacteria and then the immune system takes over for the rest
What do bactericidal drugs do?
Kill bacteria
What do bacteriostatic drugs target?
Protein synthesis (except aminoglycosides)
What do bactericidal drugs target?
Cell wall synthesis
Who should get bacteriostatic drugs?
- Non-immune compromised
- Uncomplicated infections
Who should get bactericidal drugs?
Immune compromised (particularly if life threatening infection)
How many drugs are bacterial infections usually treated with?
1 drug
What is antibiotic synergism and when would you use it?
- Combination therapy (using 2+ antibiotics)
- Can be critical for life-threatening infections
- Infrequently would 2 antibiotics in the same class be used together
What is the MIC?
- Minimal inhibitory concentration (minimal effective dose)
- When the curve drops below the MIC you must redose
- how much drug you need to stop the bacteria from growing
When are concentration dependent antibiotics most effective?
When they have a high peak concentration
- Highest concentration kills
- Aminoglycosides
When are time-dependent antibiotics most effective?
When there is a long exposure to a drug
- Longest duration over MIC kills
- Beta-lactams
What makes up the cell wall?
Peptidoglycan
Why is peptidoglycan a target for antibiotics?
Three enzymes are needed to build the polymer and all three are targets for antibiotics
What is peptidoglycan made of?
Two amino sugars in chain cross-linked to 5 amino acids
What are the two sugars in peptidoglycan and which has amino acids attached to it?
NAG and NAM
-NAM has the amino acids on it
How are the sugars connected?
They are cross-linked via 5 glycines and this is referred to as TRANSPEPTIDASE ENZYME
What is the target for beta lactam drugs?
Transpeptidase enzyme
What are three reasons for antibiotic resistance to penicillin?
- Bacteria developed “penicillinase enzymes”
- Bacteria have resistant transpeptidase enzymes
- Bacteria have multiple resistance patterns
What is the function of an OAT?
Secretes penicillin drugs into urine, enhancing elimination
What is probenicid?
- OAT inhibitor
- Using probenicid with penicillin helps prolong blood and tissue levels of the antibiotics, giving longer duration of efficacy
Why would you not want to give probenicid to a patient with a UTI?
Because probenicid keeps the drug away from the urine so its not excreted, but with a UTI we want the drug to go to the urine