Antibiotic Lecture Part 2 Flashcards
Ampicillin:
- Bacteriostatic or Bactericidal
- Acid stable or incomplete
- Penicillinase-resistant?
Bactericidal
Acid stable
Penicillase-reistant
Hos is Ampicillin administered?
Parenterally or injection
T or F, Amoxicillin is one of the most commonly prescribed drugs in the U.S.?
True
Which has better bioavailability: Ampicillin or Amoxicillin?
Amoxicillin
What makes up Augmentin?
Amoxicillin is combined with clavulanic acid to broaden spectrum
What is Clavulanic acid and how does it work?
An antibacterial agent (not an antibiotic)
- Synthetic = inhibits the penicillinase enzyme
Why doesn’t the patient respond to penicillin V
- Patient compliance
- Microorganisms are producing penicillinase
- Bacteria causing infection is outside of the narrow spectrum of kill
Augmentin is prescribed in what 3 ways?
250 mg, 500 mg and 875 mg
- 875 mg is used for a severe infection every 12 hours
Why is it better to prescribe 1- 500 mg capsule rather than 2- 250 mg capsules of Augmentin
Regardless of the size of the capsule, there is a consistent 125 mg of clavulanic acid. By prescribing 2 capsules instead of 1, the patient receives double the dose of clavulanic acid. This might produce side effects of diahrrhea
T or F, 10% of population gets maculopapular rash. Rash responds to Benadryl and is considered an allergic reaction
False! It is NOT an allergic reaction. It is a Toxicity reaction
T or F, if you are allergic to one penicillin, you are allergic to all penicillins
True
Are cephalosporins broken down by penicillinase like penicillins?
No, destroyed by cephalosporinase. (very similar mechanism though)
Cephalosporins are well absorbed through what medium?
Through GI tract
What are some adverse reactions to Cephalosporins:
- Hypersensitivity reactions
- Gastrointestinal effects (NVDs)
- Superinfection (fungal infection; oral or vaginal)
- Nephrotoxicity
What are some oral side effects to Cephalosporins?
Glossitis: inflamed tongue; smooth, shiny red
Stomatitis: inflammation, ulcerations on buccal mucosa
T or F, Patients who are intolerant to penicillins may be intolerant to cephalosporins
True
Is Cephalosporins the first choice for any orofacial infections?
Never the first choice
Cephalosporins are active and effective in what indications
- Active against many gram positive aerobic bacteria
- Active against some anaerobic bacteria
- Effective against gram negative organisms
Describe how generations work on spectrum of kill
The higher the generation, the more broad the spectrum of kill
What generation of cephalosporins are used most in dentistry
First generation = active against gram positive cocci; limited activity against gram negative bacteria
What are common cephalosporin drugs in first generation
Cephalexin (Keflex)
Cefadroxil
- cephalosporin drugs begin with either “cef” or “ceph”
Erythromycin is bacteriostatic or bacteriocidal
Bacteriostatic
- Bactericidal at high doses or when used against highly susceptible organisms
What is the mechanism of action of Erythromycin
- Inhibits protein synthesis by binding to the ribosome at a site near peptidyltransferase to inhibit peptide bond formation. End result is suppressing bacterial growth due to the lack of protein production
Erythromycin is more effective against what type of bacteria
Gram positive cocci (Staph and Strep)
Erythromycin can cause bile to back up into the liver resulting in what?
Cholestatic hepatitis
What about Erythromycin causes poor patient compliance
It causes diarrhea
Which drug was formerly an alternate drug of choice for orofacial infections for patients who were allergic to penicillins?
Erythromycin
- No longer effective against oral organisms due to resistance
- No longer used in dentistry
3 reasons why we don’t use erythromycin anymore in dentistry
- Oral bugs are resistant to drug
- GI side effects (poor patient compliance)
- Dangerous drug interactions
T or F, Erythromycin is a red flag drug in dentistry
True, interacts adversely with many commonly prescribed medications and outcome of interaction is often serious and potentially life-threatening
