Le29.Intro to Antibiotics Flashcards
MOA of tetracyclins?
Inhibit protein synthesis at ribosome
MOA of Erythromycin?
Inhibit protein synthesis at ribosome
Side affects of Erythromycin? (2)
- 3A4 Inhibitor
2. Lots of GI cramping-stimulates the motilin receptor
Why do erythromycin and clarithromycin inhibit 3A4, while azithromycin does not?
Erythromycin and Clarythromycin are 14 carbon molecules while azithromycin is a 15 carbon molecule
When is clindamycin indicated?
For patients allergic to penicillin with odontogenic infections
What serious side affect is associated with clindamycin but can occur with most any antibiotic? What antibiotic is most often used to treat?
Pseudomembranous colitis from C-dificile overgrowth due to antibiotic disproportionally killing normal flora). P. colitis leads to life threatening diarrhea. Tx w/ Metronidazole.
Why are sulfonamides so rarely used to tx oral infections?
B/c most odontogenic bacteria are resistant to sulfonamides.
Bactrim is a combo of sulfamethoxaxole & trimethoprim. What is its MOA?
Inhibits folic acid, which bacteria require.
What drug type should not be given concurrantly with sulfonamides? Why?
Local ester anesthetics can inhibit the action of sulfonamides
What 3 bactericidal antibiotics share the MOA of cell wall inhibition?
Penicillins, cephalosporins, and vancomycin
Vancomycin is normally given via injection, when is it given orally?
During tx of C-dificile
MOA of Metronidazole (flagyl)?
Inhibits DNA synthesis
MOA of Quinolones (ex. ciprofloxascin (cipro))?
DNA gyrase inhibitor (prevents unwinding of DNA)
When are quinolones generally used?
For GI infection, to prevent Montezuma’s revenge
What negative side affects are associated with quinolones?
-Blocks 1A2, therefore raising theophyline (super caffeine, used in asthma tx) levels
MOA of rifampin?
Inhibits DNA synthesis
When is rifampin indicated?
For TB infections
What is the major drug interaction associated with Rifampin? Why?
Rifampin is a 3A4 inducer and therefore can decrease effectiveness of oral contraceptives
MOA of Aminoglycosides, such as streptomycin?
Inhibits protein synthesis at ribosome.
When are aminoglycosides indicated?
Aminoglycosides are given via injection for individuals with severe gram negative aerobic infections (must be pretty sick b/c aminoglycosides have such a low TI).
What are 2 negative side affects of aminoglycosides?
At high blood levels => hearing loss & kidney problems (odo nephrotoxicity)
MOA of Nystatin? In what form is Nystatin given?
Nystatin is given as a rinse or lozenge for oral candidas infection and Inhibits cell membrane synthesis; anti-fungal targets ergosterol.
MOA of Amphotericin B?
Inhibits cell membrane synthesis; anti-fungal that inhibits ergosterol.
When is Amphotericin B indicated?
As a rinse or lozenge for oral candidas infections or IV for life threatening fungal infection.
Neg side affects (3) of amphotericin B?
- Liver Toxicity
- Seizures
- Severe Allergic Rxn
