Week 3- Antibiotics Flashcards
(128 cards)
What are narrow spectrum antibiotics?
antibiotics effective against only a few microorganism with a very specific metabolic pathway or enzyme
tetracycline is contraindicated for which types of pts and has an adverse effect on which population?
contraindicated for children under 8 bc TCN binds to calcium causing discoloration and hypoplasia of teeth and has an adverse effect on pregnant women bc TCN may retard fetal skeletal development
MOA of aminoglycosides
Bacteriocidal
most effective for aerobic gram (-) bacteria
for serious to life-threatening infections with serious toxicities (ototoxicity and nephrotoxicity most prevelant)
rearely used in PO form except for bowel pre-op bowel cleanse
Adverse effects of macrolides?
Jaundice
Hepatotoxicity
Superinfection
Macrolides are highly protein bound and can have serious interaction with other protein-bound drugs
what is the MOA of Sulfonamides?
bacteriostatic by preventing Bacteria (not human) synthesis of Folic Acid
Is pyridium an antibiotic? If not, what is it?
no, its an analgesic
Amoxicillin (PO) and Ampicillin (PO/IM/IV) fall under which type of Penicillan? Which bacteria are they good for?
Aminopenicillins. Good for gram (-) and gram (+) but not Beta lactamase organisms.
In which one of the following clinical situations is the prophylactic use of antibiotics NOT warranted?
A. Preventions of meningitis among individuals in close contact with infected pts
B. Pt with a hip prosthesis who is having a tooth removed
C. Presurgical treatment for implantation of a hip prosthesis
D. Pt who compains of frequent respiratory illness
E. Presurgical treatment in GI procedures
D- respiratory illness may be of viral origin and chronic disorders may not warrant prophylactic use of AB
Name the drug in 4th gen cephalosporin and explain its importance
Cefepime (maxipime) IV/IM
better gram (+) than 3rd gen and effective against bugs that have developed resistance to earlier generations of cephalosporins
An elderly diabetic pt is admitted to the hospital with pneumonia. The sputum culture stains for a gram(-) rod. The pt is started on IV ampicilin. Two days later, the pt is not imporving, and the microbiology lab reports the orgnism to be a B-lactamase-producing H.influenzae. What course of treatment is indicated?
A. continue IV ampicillin
B. switch to IV cefotaxime
C. switch to oral vancomycin
D. add gentamicin to the ampicillin therapy
B- cefotaxime (claforan) IV/IM 3rd gen for gram (-) and resistant to B-lactamase
Ampicillin is not resistant
vancomycin is for gram (+) serious infections
Name the gram (-) bacteria
Salmonella
Klebsiella
Helicobacter
Legionella
Escherichia
Spirochaetes
Neisseria
Shigella
Moraxella
Proteus
Hemophilus
Yersinia
Pseudomonas
Macrolides are the drug of choice for which illnesses?
Drug of Choice for “Atypical” Pneumonias:
Legionnaire’s disease (Azithromycin)
Mycoplasma pneumonia (erythromycin or tetracycline)
Chlamydia pneumonia
A pt with degenerative joint disease is to undergo insertion of a hip prostheis. To avoid complications dur to postoperative infection, the surgeon will pretreat this pt with an AB. This hospital has problems with MRSA. Which is adequate?
A. Ampicillin
B. Imipenem/cilastatin
C. gentamicin/piperacillin
D. Vancomycin
E. cefazolin
D. Vancomycin
none of the others can combat MRSA
Imipenem/cilastatin is a carbapenem
ampicillin and cefazolin (1st gen) do nothing
Describe the antibiotic MOA: Bactericidal
they cause the death of susceptible bacteria DIRECTLY (bacteriCIDAL- suiCIDAL)
identify the aminoglycosides
Gentamicin (Garamycin) (IM/IV)
Kanamycin (Kantrex) (IM/IV)
Neomycin sulfate (PO)
Streptomycin (IM)
Tobramycin (Nebcin) (IM/IV)
Amikacin (Amikin) (IM/IV)
Paromomycin (Humatin) (PO)
Diagnosis? Caused by what?

Yeast Vaginitis caused by low levels of microflora (superinfection)
what can you prescribe to a pt with pseudomembranous colitis caused by C. diff?
DOC is metronidazole (flagyl) then try vancomycin is all fails
A 30 year old male is diagnosed to be HIV +. His CD4+ count is 200 cells/cm and his viral load is 10,000 copies/mL. In addition to receiving antiviral therapy, which of the following is indicatd to protect him agaisnt pneumonia due to PCP (pneumocystis jiro-veci)?
A. trimethoprim
B. Ciprofloxacin
C. Co-trimoxazole (bactrim)
D. Clindamycin
C- Co-trimoxazole or Bactrim is = Sulfamethoxazole + trimethoprim
Describe 1st Gen Cephalosporins
Beta lactam ring
sensitive to lactamase
good gram + coverage
Indicated for: URI, OM, surgical prophylaxis
What are the Mechanism of Action (MOA) of antibiotics?
Bactericidal or Bacteriostatic
Identify the Carbapenems and their routes
Ertapenem (Invanz) (IV/IM)
Meropenem (Merrem) (IV)
Imipenem/cilastatin (Primaxin) (IM/IV)
Doripenem (Doribax) (IV)
Which Penicillans are more likely to cause a hypersensitivity reaction and why?
Natural Penicillans becuase it comes from a mold
If a pt tests positve for meningitis, which Ab is the DOC [drug of choice]? why?
Ceftriaxime (Rocephin) IV/IM because they can cross the CSF, longer half life and once a day dosing
(*or Cefotaxime (Claforan) IV/IM* but not once a day dosing)
Why are Penicillins not effective against some bacteria?
Some bacteria secrete penicillinase (betalactamse) that splits the beta-lactam ring** **









