Anti-Infectives Part 2 Flashcards
T/F: Carbapenams have cross reactivity with PCNs and cephalosporins.
True
What was the first carbapenam, what is it coformulated with, and why?
Imipenem - coformulated with cilistatin bc imipenem alone is too nephrotoxic.
T/F: Carbapenams are commonly used across many medical specialties.
False: carbapenams are very strong medications and use must be approved by an ID specialist.
What is the only carbapenam that doesn’t cover pseudomonas?
Ertapenam
List two important pharmacokinetic characteristics of carbapenams.
They are only available IV
They have excellent CNS penetration
What is the biggest caution in using carbapenams and which carbapenam is of least concern regarding this caution?
They lower seizure threshold - meropenam has the least effect on seizure threshold.
What are the three broadest spectrum beta lactams?
Cefepime (4th gen cephalosporin)
Zosyn (Piperacillin + Tazobactam)
All carbapenams except ertapenem
What do the three broadest spectrum beta lactams cover?
Gram positive (including MSSA and Strep), and gram negatives including pseudomonas.
What do the three broadest spectrum beta lactams NOT cover?
MRSA, Vancomycin Resistant Enterococcus (VRE), and atypical bacteria
What does vancomycin cover and not cover?
Very powerful against gram pos - MRSA and enterococcus. Does NOT cover gram neg.
What is a caution in the use of vancomycin?
Nephrotoxicity
What specialties can order use of vancomycin?
ID team must approve long term use.
How is vancomycin administered and what are its uses?
PO: not absorbed - used only for C Diff
IV for any other use
What is Red Man’s Syndrome and how is it resolved?
Excess HST release when vancomycin is administered too quickly - slow the infusion rate.
What do the macrolides cover?
Hodge-podge of gram pos and gram neg plus the atypicals.
List three atypical bacteria covered by macrolides.
legionella, mycoplasma, some chlamydia strains
What disease does legionella cause?
Community acquired pneumonia with GI symptoms
List three macrolides and what is unique about each.
Erythromycin: must be dosed qid
Clarithromycin: doesn’t require qid dosing
Azithromycin: used w/ ceftriaxone to treat chlamydia and gonorrhea and doesn’t require qid dosing
When are macrolides typically used in management of gram positive infections?
In patients allergic to PCN.
What is true about allergic reactions to macrolides?
Allergy is rare and often misreported
What is a unique side effect of clarithromycin?
Metallic taste develops about an hour after admin.
What drug is known as a Z-Pack and how is it dosed?
Azythromycin - 500mg on day 1 and 250mg x 4 days
What is the IV dosing of azythromycin?
500mg x 5 days (long half life)
What STI is treated with azythromycin? What is the dose for this use? What other STI is treated simultaneously and what should also be tested for?
Chlamydia - 1g
Treat gonorrhea concurrently with ceftriaxone
Also do an RPR to test for syphilis
What do the tetracyclines cover?
Hodge-podge of gram pos and neg plus tickborne diseases (RMSF and Lyme)
Tetracyclines are chelating agents. What does this mean and how is the effect managed?
Binds to heavy metals and then will not absorb. Space administration from ingestion of milk, yogurt, multivitamins, etc.
What is the first line abx for early Lyme disease?
Doxycycline
What is minocycline used for?
acne - kills the causative bacteria and has anti-inflammatory properties. Neisseria Meningitidis (meningococcal meningitis)
In what patients should tetracyclines not be used and why?
Pregnant females and kids under 8. It will bind Ca and cause teeth yellowing and deformities.
What do fluoroquinolones end in and what are some examples?
All end in oxacin - ciprofloxacin, norfloxacin, ofloxacin
What is the mechanism of action fluoroquinolones?
Bind and inhibit DNA-gyrase. DNA-gyrase is an enzyme that unwinds DNA for replication.
What is the father of the fluoroquinolones, how is it administered, and what are its uses?
Ciprofloxacin (PO) - pseudomonas, chlamydia, and anthrax.
What are newer fluoroquinolones most commonly used for and what do they not cover?
gram pos - especially in community acquired pneumonia. No coverage of pseudomonas.
List two examples of fluoroquinolones.
Ofloxacin and Levofloxacin
What do fluoroquinolones have in common with the macrolides?
Cover atypicals - macrolides do it better
What is a concerning adverse effect of fluorquinolones and what is its black box warning?
AE: QT prolongation
Black Box: tendon ruptures
What two abx classes cover atypical bacteria?
macrolides and fluoroquinolones
What do fluoroquinolones have in common with tetracyclines?
They are chelators - avoid milk, yogurt, multivitamins.
In what patients should fluoroquinolones be avoided and why?
Pregnant females and children under 18 because of soft tissue malformation.
How are fluoroquinolones eliminated?
Renally
