Antibiotics Flashcards
Test 4
What does antibitoic mean?
against life
What was the 1st true antibiotic?
PCN
Briefly describe Abx history
Ancient Egypt -> moldy bread
Paul Ehrlich -> Treated syphyllis w/ chemo
Bayer -> discovered sulfa drugs during WWI & used them in WWII
Who discovered PCN?
Alexander Fleming
By accident
What is the best way to figure out what antibiotic to give for severe infections?
C&S = culture & sensitivity test
Gram positive bacteria is colored ______ and gram negative is colored _____ d/t the thickness of the __________ layer
purple/blue
pink/red
peptidoglycan
What is the target for Abx that are specific for gram positive bacteria?
They inhibit the peptidoglycan layer
The peptidoglycan layer in gram negative bateria is _____
thin
Describe gram negative bacteria
thin peptidoglycan layer
2 cell membranes w/ lipopolysaccharides
Describe how we want to Tx gram negative bacteria
We want to slow down the growth to allow immune system to swallow instead of killing them off.
Killing them off will release a bunch of endotoxins into bloodstream d/t lipopolysaccharides in the cell membrane being destroyed. Need to slow their growth and let WBC swallow them.
What are gram positive infections vs gram negative?
positive: Staph
Strep
Negative: E. coli
Enterococcus
Enterobacter
Proteus
Klebiella
(Gut bateria)
What is a broad spectrum Abx?
effects multiple types of bacteria gram positive and neg
What are the 5 MOA for Abx?
- Cell wall inhibitor: Gram positive
- Cell membrane inhibitor: Gram negative
- inhibition of RNA/DNA synthesis
- Inhibit folic acid synthesis within bacteria
- Protein synthesis inhibitor with ribosomes: broad spectrums
Drugs: Penicillin, Cephalosporin
-cillin
Class: Abx
MOA: Inhibit cell wall synthesis (gram +)
-Beta-lactam ring attaches to the enzyme that cross-link peptidoglycas & prevent cell wall synthesis
PCN: 5 ring structure
Ceph: 6 ring structure
If you have an allergy to either one of these cant take the other
What is the most common allergy reaction in Abx?
Skin hypersensitivity
Anaphylactic shock
Drugs: Carbepenem
-penem
Class: Abx
MOA: Inhibit cell wall synthesis (gram +)
Cross BBB
Can use if PCN/Cephalosporin resistant
If the bacteria has a Beta-Lactam ring, what does this mean?
Resistant to PCN & Cephalosporin
Drugs: Vancomycin
Class: Abx
MOA: Inhibit cell wall synthesis (gram +)
-Resistant to beta-lactamase; alt for PCN
Uses: MRSA
More likely to develop AE: Red neck syndrome (release of histamines from mast cells), irritating to tissues, chills/fever, ototoxicity, nephrotoxicity
Can cause resistance
Drug of last resort
Drugs: Polymyxin
Class: Polyteptide Abx
MOA: Disruption of Cell Membrane (gram -)
-binds to phospholipids
Topical Triple Abx –> Neosporin
SYSTEMIC IS A LAST RESORT
Causes neuro/nephrotoxocoty
What is the biggest group of Abx?
Inhibitors of protein synthesis
Broad spectrum
Drugs: Tetracycline
Class: Abx
MOA: Inhibition of protein synthesis by selectively targeting bacteria ribosomes (70S)
-Broad spectrum
- Inhibits growth w/o killing
Structure: 4 cyclic rings
AE: Alot of them; main ones: GI & teeth
DO NOT GIVE THESE TO CHILDREN
especially before their teeh have grown in
What are bacteria ribsomes vs human ribosomes?
bacteria: 70S
human: 80S
Drugs: Eythromycin
-mycin
Prototype
Class: Macrolides Abx
Structure: 4 ring structure connected altogether (open in center)
MOA: Inhibition of protein synthesis by selectively targeting bacteria ribosomes (70S)
-Broad spectrum
Azizthromycin: Z-pack
Neomycin: topical
SE: Flactulance
Drugs: Ciprofloxacin
Class: Fluoroquinolones Abx
MOA: Inhibition of Nucleic Acid synthesis (broad spectrum; neg > pos)
-inhibits RNA/DNA
-binds to DNA gyrase
Uses: UTI, RTI
Drugs: Sulfonamide, Trimethoprim
Class: Abx
MOA: Inhibition of Folic Acid synthesis which is neeed to produce nucleotides that form DNA/RNA
-competitive inhibition
-Incorporated into important molecules
Sulfonamides: Bactrim, Septra
AE: changes is WBC production (Hematopoietic)
What is the precursor to production of Folic acid in bacteria? What is similar to its structure? Describe how competitive inhibition works with this?
PABA: para-aminobenzoic acid
bactrim
bactrim has a similar structure to PABA –> binds in the active site of bacteria and shuts down pathway to create folic acid needed for RNA/DNA synthesis
Drugs: Ketoconazole, Lamisil
Class: Antifungals
MOA: Cell membrane inhibition
Topical
Drugs: Hydroxychloroquine, Metronidazole
Class: Antiprotozoan agent
Hydroxychloroquine Uses: Malaria
Metronidazole uses: STD
SE: BLACK HAIRY TONGUE grossssss
Birth defects, Cancer
Drugs: Niclosamide, Ivermectin, Permethrin
Class: Anti-Parasitic Worms
Niclosamide uses: tapeworms
Ivermectin uses: roundworms
Permethrin uses: lice
What increases risk of antibiotic resistance? How?
Stopping your Abx before you finish them
Although you feel well when you stop taking them, those highly resistant bateria are the ones that are still left
This causes an overgrowth of those highly resistant bacteria
Which means next time when you take that Abx it will be much harder to kill that bacteria
Which Abx has the most toxic SE?
Tetracyclines
Carapines
Vanc
Which Abx are you most likely to have an allergy to or develop resistance to?
PCN
What disease can Abx cause?
C. Diff
Gross….
