Antimicrobial overview Flashcards
Define antibiotics.
Chemicals that inhibit or kill microorganisms, bacteria only.
Key points: selective toxicity is what?
Harm bacteria without harming our cells.
Ideal bacteria would be a bacteria that .. and example would be?
Kill bacteria with no side effects (penicillin G).
What are the types of antibiotics?
Bacteriostatic, bacteriocidal, sulfonamides.
What is bacteriostatic? what are some examples?
Inhibit bacterial cell replication. Ex. Tetracyclines, Erythromycin, Chloraphenicol.
StaTEC.
What is bacteriocidal? what are some examples?
Causes microbial death and lysis. ex.
Penicillins, Aminoglycosides (gentra/tobra), Cephalosporins.
PACS a punch
Sulfonamides are..
Either cidal or static according to the environment.
Surfs between cidal and static.
What does this graph show? which is which?
bacteriocidal vs bacteriostatic
What antibiotics are involved in cell wall synthesis? 5 types.
(PCCMV)
Penicillin (G, Ampicillin)
Cephalosporin (Ceftriaxone, Ceftaroline)
Carbapenems (Imipenam)
Monobactams (Aztreonam)
Vancomycin (Tricyclic Glycopeptide)
“I hit a wall, please come C my Vehicle”
Which antibiotics target DNA/RNA replication? 3 types.
(MR.Q)
Quinolones DNA gyrase, Replication (Ciprofloxacin, Levofloxacin)
Rifampin (Rna polymerase)
Metronidazole (Damage DNA)
Which antibiotics target protein synthesis? 4 types.
(MAT C)
Tetracyclines (Doxycycline)
Aminoglycosides (Gentamycin, Tobramycin)
Chloramphenicol
Macrolides: Azithromycin, Erythromycin
Which antibiotics target cell membrane? 2 types
Polymyxins
Daptomycin
Which Antibiotics target folic acid? 2 types.
Trimethoprim
Sulfonamides (Sulfamethoxazole)
Out of the protein synthesis antibiotics, which target 50s?
50s: Macrolides, Chloramphenicol, Lincosamides, Streptogramins,
Oxazolidines,
Out of the protein synthesis antibiotics which target 30s?
30s: Tetracycline, Glycylcyclines, Aminoglycosides
What is Gut flora? how does ABx affect this?
Microflora is natural in our GI system that balances overgrowth of pathogens. When you take an ABx you wipe the naturally occurring gut flora and lead to overgrowth of back bacteria.
What are some examples of resistant bacteria and what are some treatments that work against them?
Resistant: C. Diff, C. Albicin.. Vancomycin is treatment for C. diff.
What method is used to begin treatment immediately without knowing the bacteria?
Empiric therapy, which is an educated guess based on guidelines.
What are some first choice drugs for Empiric therapy? What are some of the things they treat?
Penicillin G– Treponema pallidum, syphilis.
Rifampin/isoniazid/pyrazinamide/ethambutol– treatment for Mycobacterium TB- RIPE.
Piperacillin/Tazobactam+ Tobramycin–
(Beta lactam/beta lactamase inhibitor with an aminoglycoside.) - provide synergy.
Pneumonia, pseudomonas aeruginosa.
What are some contraindications for neonates with ABX?
Chloramphenicol –> Gray Baby syndrome [Lower dose]
Sulfonamides Kernicterus or Toxic Encephalopathy [Contraindication]
What are some contraindications for children with ABX?
Tetracycline Bone growth/Teeth discoloration
What are some contraindications for CHF patients with ABX?
Ticarcillin disodium/Clavulanate potassium Edema/Arrythmia
What ABX should you avoid while pregnant?
Metronidazole
Sulfonamides
Antifolate drugs (Tri)
Fluoroquinolones
Tetracyclines
The use of a cell wall inhibitor and a protein synthesis inhibitor together, lead to what?
A greater response for treatment, increased synergy.
some examples of Penicillins and amino-glycosides you can use together are…
Penicillins- Penicillin G, Ampicillin, Piperacillin
Aminoglycosides- Gentamycin, tobramycin, amikacin
All beta-lactams have what Mechanism Of Action?
Inhibit peptidoglycan transpeptidase (cross-linking).
Penicillin binding protein (PBP)
Trigger autolysins.
All betalactams undergo what kind of clearance?
Renal clearance.
Side effects of Beta Lactams include:
NVD, Superinfection of GI tract: C. Diff, Allergy.
Beta Lactams Mechanism of resistance’s are:
Changes in PBP, Tolerance: Deficiency in autolytic enzymes, changes in porins (gram -)
B-lactamase.
T/F. Cephalosporins have the same MAO / MOR as penicillin.
true.
How many generations of cephalosporins are there? what are they?
5 generations, they are :
Cefazolin 1st (PEKS)
Cefoxitin, 2nd (HEN PEK)
Ceftriaxone 3rd ACES
Cefepime 4th (Gram +)
Ceftaroline 5th
Cephalosporin generations 1, 2, 3 have potency against what pathogens?
- Proteus mirabilis, Escherichia coli, Klebsiella pneumoniae,
- Haemophilus influenzae, Enterobacter aerogenes, Neisseria gonorrhoeae
- Acinetobacter calcoaceticus, Citrobacter diversus, Enterobacter cloacae, Serratia marcescens
Should you give cephalosporin if the patient has had a severe penicillin allergy?
Fuck no.
the Monobactam aztreonam is a B-lactam that is used for what?
If the pt has had an allergy to penicillin. Very small percentage of allergic reaction
What is an important tricylic glycopeptide that targets cell wall synthesis that is the Treatment for C. Diff.
Vancomycin.
What is the mechanism of action of vancomycin?
Inhibitor of peptidoglycan synthase (attaches to NAG and NAM) binds to D-Ala-D-Ala.
What is the primary therapeutic use of vancomycin?
Clostridioides difficile (PO)
What is the MOR related to vancomycin?
D-Ala-D-Ala -> D-Ala-D-Lactate and VRE- vanco resistant enterococci when you overproduce D-Ala.
Cyclic Lipopeptide have what method of MOA? whats an example?
Binds to cell membrane, forms pores. Daptomycin.
DAPS HOLES.
Whats the therapeutic use of Daptomycin?
VRE vanco resistance, MRSA.
Tetracylines have what kind of MAO?
30s protein synthesis inhibitor.
Is tetracycline bacteriostatic or bacteriocidal?
Bacteriostatic.
When is doxycycline a good choice? whens it a bad choice?
good- Fecally eliminated- good in renal failure.
bad- Pregnancy.
Glycylcyclines have what MOA? example?>
30s Protein synthesis inhibitor. Tigercycline.
What is an issue with a glycylcyclines?
Tigecycline has a higher mortality rate, reserved for difficult infections.
What is the MOA and examples of macrolides?
50s Protein syn inhibitor. erythromycin, azithromycin.
What are some uses for macrolides?
chlamydia, URTI (upper respiratory tract infection)
What is a side affect of macrolides?
Prolong the QTc interval.
What is the MOR for macrolides?
methylation of 23 rRNA-binding site, prevents binding.
Lincosamides have a MOA that…
50s protein synthesis inhibitor
lincosamides major drug is? what is it used for? what can it lead to??
Clindamycin, CA-mrsa, CDAD (CCC)
Streptogramins differ because they are …
Used in same dose for synergy.
What are the streptogramins?
quinopristin/dalfopristin
What is the MOA of streptogramins?
50s ribosome subunit.
Aminoglycosides are important because..
They are synergic with B lactams.
aminoglycosides have a MOA that is… what are examples of these?
protein syn inhibitor. 30s. Gentamycin and tobramycin.
Sulfonamides examples? what do each do?
Sulfamethoxazole- inhibit dihydropteroate syn.
trimethoprim- inhibit dihydrofolate reductase
What is the common action in sulfonamides?
Inhibition of folic acid.
What are some side effects of sulfonamides?
Rash: sulfa allergy, SJS, TEN.
