ID: Antibiotics Flashcards
Dapsone is a _______ drug, used mainly in treating what disease?
Sulfa ; Mycobacterium Leprae
Describe the MOA of Bactrim.
Trimethoprim - inhibits dihydrofolate reductase
Sulfamethoxazole: inhibits dihydropteroate synthetase
What class of antibiotics does Vancomycin belong to? What is it’s MOA? What is the appropriate initial loading dose? How is it monitored?
Glycopeptides - inhibits cell wall synthesis similar to b-lactam antibiotics
15-20 mg/kg load
Trough after 3rd or 4th dose . at least 10-15 mcg/ml level
What pathogens are covered by Linezolid? What is it’s mechanism of action? What medication should be avoided concomittant with this antibiotic?
Most Gram + cocci ( staph, strep, enterococcus)
Binds 50s ribosomal subunit ( similar to macrolides)
Do not give with MAOI’s or SSRI’s ( Serotonin Syndrome)
When should vancomycin troughs be measured?
after 3-4th dose, the medication should reach steady state. Goal is 10-15 mcg/ml
How is vancomycin cleared?
Renal, as unchanged drug. Clearance is directly related to creatinine clearance.
What are the 4 b-lactam antibiotic classes?
Penicillins, cephalosporins, carbapenems, and monobactams
What coverage does Aztreonam provide? Why prescribe it?
Strictly gram - coverage, ok for those with PCN allergies
Cefazolin and cephalexin are ________ generation cephalosporins.
First Generation
Mostly Gram + coverage, some gram - like e.coli
Which penicillin is given orally? Intravenously?
Pen G is given IV. Pen VK is oral.
What is the general MOA of all b-lactam antibiotics?
They interact with penicillin binding protein, disrupting cell wall synthesis ( peptidoglycan to be precise.)
What is the bacterial activity of the natural penicillins?
Aerobic gram + ( staph, strep, enterococcus, listeria)
Aerobic gram - ( nisseria , haemophilus)
Anaerobic ( clostridium… except c.diff)
Spirochetes ( treponema and leptospira)
Antistaphylococcal penicillins include___.
Oxacillin/ Nafcillin
The aminopenicillins include _____ and ____.
Amoxicillin and ampicillin
addition of beta-lactamase inhibitors such as sulbactam/clavulanic acid are common
Borellia burgdorferi can be treated with which penicillin drugs?
amox/ amp or augmenten
Primary regime is doxycycline unless contraindicated. (age
What is the most common extended spectrum penicillin drug?
Pipercillin/ Tazobactam (Zosyn)
Ticarcillin / clavulanate)
Coverage of Zosyn?
Gram +
Gram - (neisseria, h. flu, enterobaceteriacea, pseudomonas )
Anaerobes ( clostridia, except c.diff, and bacteroides)
What organisms are included in the enterobacteriaceae family?
Shigella, salmonella, e.coli, klebsiella, proteus, serratia …to know most important ones
Cefoxitin/ Cefuroxime are ______ generation cephalosporins.
second
Cefotaxime and ceftriaxone are _____ generation cephalosporins.
Third
This 4th generation cephalosporin has broad coverage of gram - and + bacteria as well as pseudomonas.
Cefepime
Ceftaroline is the only commercially available ____ generation cephalosporin.
Fifth
What two 2nd generation cephalosporins have moderate anaerobic bacterial coverage?
Cefoxitin and cefotetan
What percentage of PCN allergic people will have a cephalosporin reaction?
5-10%
Why is imipenem administered with cilistatin?
The abx is rapidly degraded in the kidney by dhydropeptidase I. Cilistatin inhibits this enzyme
Notably, the other carbapenems dont have this requirement.
Which carbapenem only requries qd dosing? What is the disadvantage of this drug?
Ertapenem is qd. However it sacrifices gram + coverage and pseudomonal and acinetobacter coverage because of that property.
A feared complication of carbapenem drugs is ______, meaning it should not be administered to patients with what underlying disorders?
Seizures.
Avoids in patients with previous seizure disorder, renal insufficiency.
This medication has strict gram - coverage and can be viewed as a non-toxic alternative to aminoglycosides, or patients with PCN allergy.
Monobactams ( Aztreonam)
This lipopeptide antibiotic is active against gram + organisms, many resistance strains of staph and strep and VRE.
Daptomycin
This older antibiotic has limited gram - coverage of pseudomonas, most enterobacteriaceae, and H. influenza. It is moderately nephrotoxic and neurotoxic.
Colistin
________ exhibits limited coverage of staph, niesseria, and mycobacterium species, and causes red discoloration of tears and urine.
Rifampin
The most potent inducer of the CYP450 system is _____.
Rifampin
Major side effects of aminoglycosides include ______.
nephrotoxicity ( 5-10% in patients without other risk factors) and ototoxicity.
Macrolides exert their antimocrobial effect via _____.
Binding the 50s ribosomal subunit
In addition to atypical bacterial infection coverage, ________ also over coverage of some gram +, gram -, spirochete and mycobacterial infections .
macrolides
The advantage of this medication is that it is taken up quickly by body tissue and released over subsequent days, making a 5 d course effective for 10 days.
Azithromycin
What are the feared toxicities of macrolide antibiotics?
QT interval prolongation and Cytochrome inhibition ( except azithromycin)
Decolonization of MRSA is effective about _____ % of the time ,and consists of what regimen?
60-65%
Doxycycline bid x 14 d and Rifampin on last 3d
Mupirocin ung for new lesions
Chlorhexidine body wash bid
Chlorhexidine mouth gargle bid-tid
total of 14 days of treatment