Antibacterials Flashcards
What are the mechanisms of action for antibacterial drugs
Inhibition of: Cell Wall Synthesis Cell Membrane Function Protein Synthesis Nucleic Acid Synthesis Other metabolic processes
How can one determine which antibiotic a bacteria is most susceptible to?
Culture and Sensitivity Testing
Adverse reactions to anti-infective therapy
Kidney Damage GI Damage Hypersensitivity Rxns Neurotoxicity Superinfections
Mechanism of action for Penicillin? What specific molecule does it target?
Disruption of Cell Wall. It targets the β-Lactam Ring
Which bacteria are penicillins generally effective against?
Gram Positive
What Gram-positive bacterium is often resistant to penicillins?
S. Aureus
A patient with a penicillin allergy would likely be allergic to __________
Cephalosporins (this is still in our notes and text but modern research shows its not as likely as once thought.)
Cephalosporins are:
wide spectum antibiotics similar to penicillin
What type of bacteria are generally susceptible to cephalosporins?
Gram Negative
What is the most common antibiotic allergy?
penicillin
Cephalosporins mechanism of action
Disrupt cell wall synthesis during bacterial cell division
What is the mnemonic used to remember which bacteria are not susceptible to cephalosporins?
LAME: Listeria Atypicals (mycoplasma and Chlamydia) MRSA Enterococci
Most serious adverse effect of cephalosporins involves the _______
GI tract - nausea, vomiting, etc.
What is often treated by tetracyclines?
Lyme Disease
Rocky Mountain Spotted Fever
H. Pylori
Chlamydia
What is a significant contraindication to most antibiotics? Why?
Renal or Hepatic complications. They can interfere with or alter metabolism of the drug.
Tetracycline method of action?
Inhibit protein synthesis to prevent bacterial cell division.
Tertacycline is Bacterio-_____, which means it:
-static. Prevents further growth/replication of bacteria.
Erythromycin is bacterio-_______ at low doses and bacterio-________
-static, -cidal
What class of antibiotic includes erythromycin?
Macrolides
What is Fidaxomicin most often used to treat? What else can it treat?
C. Diff.
It is not approved to treat any other infection.
What class of antibiotic includes Gentamycin?
Aminoglycosides.
Gentamycin is bacterio-______
-cidal
What type of cell does gentamycin target? What is its method of action?
Gram Negative bact.
Inhibits protein synthesis
When would you use gentamycin? How is it administered?
For serious systemic infections.
Administered parentally because it is poorly absorbed in GI tract.
Aminoglycoside’s major toxic effects are
Ototoxicity and Nephrotoxicity
What is an example of fluoroquinolones? What bacteria do they target?
Ciprofloxacin (cipro).
They are active agains ALL gram negative bacteria.
Fluoroquinolones are bacterio-_______
-cidal
Fluoroquinolones such as Cipro are the preferred drug to treat _______________
Uncomplicated UTI’s
Fluoroquinolones are approved for what age group?
Only 18 years and older. Black Box warning.
Ciprofloxacin’s method of action
Interferes with DNA replication in ALL gram-negative bacteria.
What was the first antibiotic class ever discovered?
Sulfonamides
Sulfonamides are bacterio-_______
-static
Sulfonamides are teratogenic. What does this mean?
They may disrupt fetal development.
What prototype drug is used to treat TB
isoniazid (INH)
How is TB treated?
Multidrug therapy including INH and Rifadin for 6-24 months.
How might Rifadin affect bodily fluids?
It can turn them purple or orange.
A unique adverse effect of TB drugs is
decreased effectiveness of oral contraceptives.
