Infectious Disease Flashcards
What’s Gram-negative organism?
Thin cell wall
Take up safranin counterstain
Stain pink or reddish in color
What’s Gram-positive organism?
Thick cell wall
Stain purple/bluish in color
Gram-positive bacteria consist of mainly what species?
SSLEC
Staphylococcus
Streptococcus
Listeria
Enterococcus
Clostridium
Organisms under gram-positive Cocci?
Ending in “cocccus”
Organisms under gram-positive Rods?
Propionibacterium acnes
Bacillus anthracis
Clostridium difficle, Clostridium perfringens,
Corynebacterium diphtheriae, Corynebacterium jeikeium
Listeria monocytogenes
Nocardia asteroids (branched)
Actinomyces israelii (branched)
Mycobacterium species (acid-fast)
Organisms under gram-negative Cocci?
Neisseria gonorrhoeae
Neisseria meningitidis
Organisms under Spirochetes?
Borrelia burgdorferi; Borrelia recurrentis
Leptospira interrogans
Treponema pallidum
Organisms under Atypicals?
Chlamydia/Chlamydophilia
Mycoplasma hominis; Mycoplasma pneumoniae
Ureaplasma urealyticum
Organisms under gram-negative Coccobacillary?
Acinetobactor sp.
Bartonella henselae; Bordetella pertussis
Family rickettsiaceae; Francisella tularensis
Moraxella catarrhallis
Pasteurella multocida
Organisms under gram-negative rod?
All others
Whats Minimum Inhibitory Conc (MIC)?
Lowest drug conc that prevents visible microbial growth in 24 hrs
(Gen in practice, the MIC used is to prevent growth of 90% of microorganisms MIC90)
What’s breakpoint?
Level of MIC at which a bacterium is deemed either susceptible or resistant to an antibiotic
What’s Minimum Bactericidal Conc (MBC)?
Lowest drug conc that reduces bacterial density by 99.9% in 24 hrs (kills bacteria)
What’s Synergy?
Effect of 2 or more agents produces a greater effect than each agent alone
Purpose of Antimicrobial Stewardship Programs (ASP)?
Reduce emergence of resistance
Limiting drug-related adverse events
Minimizing risk of unintentional consequences associated with Antimicrobial use
Factors to consider when selecting a drug regimen?
Etiology/epidemiology (community V. Hospital-acquired inf) of inf
Site/ severity of inf
Patient xteristic (age, body wt, renal/liver fxn, allergies, pregnancy status, immune fxn)
Spectrum of activity and pharmacodynamics/pharmacokinetics of the drug regimen
Factors to consider when monitoring for therapeutic effectiveness?
Fever curve
WBC count
Radiographic findings
Pain/inflammation
Reduction in s/sx of inf
Gram stain, cultures and Antimicrobial susceptibilities
List Hydrophilic agents
DC BAG
Daptomycin
Colistimethate
Beta-lactams
Aminoglycosides
Glycopeptides
Xtics of hydrophilic agents? (Beta-lactams, Aminoglycosides,
Glycopeptides, Daptomycin, Colistimethate)
Small volume of distribution
Renal elimination
Doesn’t achieve intracellular conc
Increased clearance and/or distribution in sepsis
Poor-moderate bioavailability
Effects of hydrophilic agents? (Beta-lactams, Aminoglycosides,
Glycopeptides, Daptomycin, Colistimethate)
Poor tissue penetration
Nephrotoxicity (ATN- Acute tubular necrosis, AIN- Acute interstitial nephritis)
Not active against atypical (intracellular) pathogens
Consider loading doses and aggressive dosing in sepsis
< 1:1 with PO to IV ratio
List Lipophilic agents
Fluoroquinolones
Macrolides
Rifampin
Linezolid
Tetracyclines
Chloramphenicol
Xtics of Lipohilic agents (Fluoroquinolones, Macrolides, Rifampin,
Linezolid, Tetracyclines, Chloramphenicol)
Large vol of distribution
Hepatic metabolism
Achieves intracellular conc
Clearance/distribution has minimal change in sepsis
Excellent bioavailability
Effects of Lipohilic agents (Fluoroquinolones, Macrolides, Rifampin,
Linezolid, Tetracyclines, Chloramphenicol)
Excellent tissue penetration
Hepatoxicity and DDI (drug-drug interaction)
Active against atypical (intracellular) pathogens
Dose adjustment generally not needed in sepsis
1:1 with PO to IV ratio
How’s the dose of Beta-lactam maximized?
By extending the infusion time (such as over 4 hrs)
Or
Given as a continuous infusion which can lead to a greater time above the MIC
Which drugs are listed under Cmax:MIC (Max plasma conc:Min inh conc)?
C FAD
Colistin
Fluroquinolones
Aminoglycosides
Daptomycin
Which drugs are listed under AUC:MIC (Area under curve:Min inh conc)?
VMT
Vancomycin
Macrolides
Tetratcyclines
Which drugs occur under T>MIC?
Beta-lactams (penicillins, cephalosporins etc)
Dose: more freq dosing, extended, continuous infusions
Which antibiotics are Cell Wall Inhibitors: bactericidal?
PCC VMF
Penicillins
Cephalosporins
Carbapenems
Vancomycin
Monobactams
Fosfomycin
Which antibiotics are DNA/RNA Inhibitors: bactericidal?
Q RMT
Quinolones (DNA gyrase/Topoisomerase)
Rifampin
Metronidazole
Tinidazole
Which antibiotics are Folic Acid Synthesis Inhibitors: bacterioSTATIC alone; bactericidal (in combo)?
Sulfonamides
Trimethoprim
Which antibiotics are Protein Synthesis inhibitors: bacterioSTATIC?
BacterioSTATIC
Except Aminoglycosides and some pathogens for Streptogramnis
Which antibiotics are Protein Synthesis inhibitors: 50S?
COMS
Clindamycin
Oxazolidinones (Linezolid)
Macrolides
Streptogramins (Quinupristin, Dalfopristin)
Which antibiotics are Protein Synthesis inhibitors: 30S?
AT
Aminoglycosides
Tetracyclines
Which antibiotics are Cell Membrane Inhibitors:Bactericidal?
PD
Polymyxins (Colistin)
Daptomycin
What warning comes with all antibacterial agents?
Risk of superinfection with prolonged use including C. difficle-associated diarrhea (CDAD) and Pseudomembranous colitis
MOA of Aminoglycosides (AMGs)?
Binds to 30s and 50s ribosomal subunits
Exhibit conc-dependent killing
Have a post-antibiotic effect (PAE)
Advantage of extended interval dosing v. Traditional dosing?
Extended interval dosing may decrease nephrotoxicity
Coverage of Aminoglycosides (AMG)?
Gram-negative bacteria (e.g. Pseudomonas)
In combo with beta-lactam or vanco: Gram-tve cocci e.g. Staphylococci and Enterococcus endocarditis
Drugs under AMGs
TAGS
Tobramycin
Amikacin
Gentamicin
Streptomycin
How do u dose AMGs?
Using IBW
Black box warning of AMGs (TAGS)?
Neurotoxicity (hearing loss, vertigo ataxia)
Nephrotoxicity (esp in renal impairment or concurrent use with other nephrotoxic drugs)
SEs of AMGs (TAGS)?
Nephrotoxicity (acute tubular necrosis - ATN)
Hearing loss (early toxicity associated with high-pitched sounds)
Adv of extended interval dosing of AMGs?
Less nephrotoxic and more cost-effective
Which has the broadest spectrum of activity?
Amikacin
What’s the peak and trough of Gentamicin for gm-negative infection?
Peak - 5-10mcg/mL
Trough - < 2 mcg/mL
What’s the peak and trough of Gentamicin for gm-tve infection?
Peak - 3-4mcg/mL
Trough - < 1mcg/mL
What’s the peak and trough of Tobramycin?
Peak - 5-10mcg/mL
Trough - < 2mcg/mL
What’s the peak and trough of Amikacin?
Peak - 20-30 mcg/mL
Trough - < 5mcg/mL
MOA of penicillins (PCNs)?
PCNs are beta-lactam that inhibit bacterial cell wall synthesis
Xtics of PCNs?
PCNs exhibit time-dependent killing
Bactericidal, except against Enterococci species (AMGs, gentamicin and streptomycin are needed for bacterial activity)
Coverage of PCNs?
Mainly active against
Gram-tve cocci (Streptococcus)
Some gram-nag entire bacilli coverage
Which PCNs have activity against Enterococci?
PAA
Piperacillin
Ampicillin
Amoxicillin
Which PCNs have activyt against methicillin susceptible Staphylococcus aureus (MSSA)?
Nafcillin
Effect of addition of beta-lactamase inhibitor to PCNs?
Adds gram-negative coverage (Proteus, E.coli, Klebsiella), H.influenza, MSSA and Anaerobic coverage
List PCNs under Aminopenicillins
Amoxicillin (Amoxil)
Amoxicillin + Clavulanate (Augmentin, Augmentin ES-600, Augmentin XR, Amocian)
Amoxicillin + Sulbactam (Unasyn)
Brand name of Amoxicillin (Aminopenicllins)?
Amoxil
Brand name of Amoxicillin + Clavulanate (Aminopenicllins)?
Augmentin
Augmentin ES-600
Augmentin XR
Amocian
Brand name of Amoxicillin + Sulbactam (Aminopenicllins)?
Unasyn
List PCNs under Natural penicillins
Penicillin (Pen VK)
Penicillin G Benzathine (Bicillin L-A)
Penicillins G Aqueous (Pfizerpen-G)
Pen G Benzathine and Pen G Procaine (Bicillin C-R)
What’s the brand name of Penicillin (Natural Penicillins)?
Pen VK
What’s the brand name of Penicillin G Benzathine (Natural Penicillins)?
Bicillin L-A
List PCNs under Ureidopenicillins
Piperacillin + Tazobactam (Zosyn)
Brand name of Piperacillin + Tazobactam (Ureidopenicillins)?
Zosyn
List PCNs under Carboxypencillins
Ticarcillin + Clavulanic acid (Timentin)
List PCNs insider Antistaphylococcal penicillins
NAFCILLIN
Oxacillin
Dicloxacillin
Which PCN must be refrigerated?
Augmentin (Amox + Clavulanate) oral SUSPENSION must be refrigerated
Which PCN is refrigerated to improve taste?
Amoxil (amoxicillin) oral suspension, stable for 14 days at room temp
How do u take Pen VK (Penicillin)? Storage after reconstitution?
On an empty stomach
Refrigerate after reconstitution
What diluent is Ampicillin IV compatible with? Stability at room temp?
NS only
Stable for 8 hrs at room temp
Which PCN is a vesicant? How can one mitigate SE?
Nafcillin
Use cold packs and hyaluronidase injections (admin thru central line is preferred)
In what case is amoxicillin (Amox) DOC for?
Acute otitis media
H.pylori regimen
Pregnancy
Prophylaxis for endocarditis
Which PCNs have activity against Pseudomonas?
Piperacillin and Ticarcillin
Effects of tetracycline & other bacterioSTATIC on PCNs?
Tetracycline may decrease the effectiveness of PCN, by slowing bacterial growth (PCNs work best against actively growing bacteria)
MOA of Cephlosporins?
Inhibit bacterial cell wall
Xtics of Cephalosporins?
Time- dependent killing with bactericidal activity
Spectrum of activity is dependent upon gen. of cephalosporin, eg activyt against staphy gen decreases with each generation, while activity against Strep and Gm-negative pathogens increases
List agents under 1st generation Cephalosporins
Cefadroxil
Cefazolin (Kefzol)
Cephalexin (Keflex)
Xtics of 1st generation Cephalosporins (Cefadroxil; Cefazolin (Kefzol); Cephalexin (Keflex))
Staphylococci activity
Covers - Proteus mirabilis, E. coli and Klebsiella species
Lower - Streptococci and Gm-negative activity (compared to 2nd/3rd generation)
Brand name of Cefazolin (1st generation Cephalosporin)?
Kefzol
Brand name of Cephalexin (1st generation Cephalosporin)?
Keflex
List agents under 2nd generation Cephalosporins
Cefaclor
Cefotetan
Cefoxitin
Cefprozil
Cefuroxime (Ceftin, Zinacef)
Xtics of 2nd generation Cephalosporins (Cefaclor; Cefotetan; Cefoxitin; Cefprozil; Cefuroxime (Ceftin, Zinacef))
Better gm-negative activity than 1st gen
Similar gm-tve activity including PEK, Haemophilus & Neisseria species (HNPEK)
Which 2nd generation cephalosporin have anaerobic activity (Bacteroides fragilis), but less gm-tve activity?
Cefotetan
Cefoxitin
Brand name of Cefuroxime (2nd generation cephalosporin)?
Ceftin
Zinacef
List 3rd generation cephalosporin agents
CEFDINIR
Cefditoren (Spectracef)
Cefixime (Suprax)
Cefotaxime (Claforan)
Cefpodoxime
Ceftazidime (Fortaz, Tazicef)
Ceftibuten (Cedax)
Ceftriaxone (Rocephin)
Xtics of Ceftazidime (Fortaz, Tazicef) 3rd generation cephalosporin?
Less gm-tve activity, but enhanced gm-negative activity, including Pseudomonas
Brand name of Ceftazidime (3rd generation cephalosporin)?
Fortaz
Tazicef
Brand name of Ceftriaxone (3rd generation cephalosporin)?
Rocephin
List 4th generation cephalosporin agent
Cefepime (Maxipime)
Xtics of 4th generation cephalosporin (Cefepime - Maxipime)?
Best gm-negative activity, including HNPEKS, Citrobacter, Acinetobacter, Pseudomonas, Enterobacter and Serratia species (CAPES)
and
Gm-tve activity similar to 3rd gen
What’s the brand name of Cefepime? (4th generation cephalosporin agent)?
Maxipime
List 5th generation cephalosporin agent
Ceftaroline fosamil (Teflaro)
Xtics of Ceftaroline fosamil (Teflaro) 5th generation cephalosporin agent?
Best Gm-tve activity
Covers MRSA
Some gm-negative activity (no Pseudomonas coverage)
What’s the brand name of Ceftaroline? 5th generation cephalosporin agent
Teflaro
Is there cross-sensitivity btw Cephlosporins and PCNs?
Cross sensitivity (< 10%) with PCN allergy
Don’t use in pts who have a type 1 mediated PCN allergy (swelling, angioedema, anaphylaxis
Which cephalosporin shouldn’t be given via Y-site or mixed with calcium-containing solns or used in neonates? Which is preferred?
Ceftriaxone (Rocephin)
Preferred-Cefotaxime (Claforan)
Which cephalosporin contains N-methylthiotetrazole (NMTT or 1-MTT) side-chain? Effect of this?
Cefotetan
Can increase the risk of hypoprothrombinemia (bleeding) and a disulfiram-like rxn with alcohol ingestion
Effect of Probenecid on all Beta-lactams?
Increase beta-lactam levels by interfering with renal excretion
MOA of Carbapenems?
They inhibit bacterial cell wall synthesis
They exhibit time-dependent killing with bactericidal activity
Coverage of Carbapenems?
Very Broad spectrum (gm-tve, gm-negative and anaerobic pathogens)
What don’t Carbapenems cover?
Atypical pathogens
MRSA
VRE
C.difficle
Stenotrophomonas
What does Ertapenem (Carbapenem) not cover?
Psuedomonas
Acinetobacter
List agents under Carbapenems?
Imipenem/Cilastatin (Primaxin)
Meropenem (Merrem)
Ertapenem (Invanz)
Doripenem (Doribax)
Brand name of Imipenem/Cilastatin (Carbapenems)?
Primaxin
Brand name of Meropenem (Carbapenems)?
Merrem
Brand name of Ertapenem (Carbapenems)?
Invanz
Brand name of Doripenems (Carbapenems)?
Doribax
Main SE of Carbapenems?
Seizures
MOA of Fluoroquinolones (FQs)?
Fluoroquinolones inhibit bacterial DNA Topoisomerase IV and inhibit DNA gyrase (Topoisomerase II)
Exhibit conc-dependent killing
Which FQs have gm-negative activity, including Pseudomonas?
Ciprofloxacin
Levofloxacin
Which FQs are referred to as respiratory FQs? Why?
Gemifloxacin
Levofloxacin
Moxifloxacin
Due to enhanced coverage of Stretococcus pneumoniae and atypical coverage
List FQs agents
OFLOXACIN
Norfloxacin (Norozin)
Ciprofloxacin (Cipro, Cipro XR)
Levofloxacin (Levaquin)
Gatifloxacin (ophthalmic only)
Moxifloxacin (Avelox)
Gemifloxacin (Factive)
What’s the brand name of Ciprofloxacin? FQs
Cipro
Cipro XR
What’s the brand name of Levofloxacin? FQs
Levaquin
What’s the brand name of Otic Ciprofloxacin? FQs
Ciprodex
What’s the brand name of Moxifloxacin? FQs
Avelox
What’s the brand name of Ophthalmic Moxifloxacin? FQs
Vigamox
What’s the dosing of Ciprofloxacin (IV/PO)?
250-750mg PO
200-400mg IV Q8-12H
What’s the dosing interval of Ciprofloxacin if CrCl = 30-50ml/min?
Q12H
What’s the dosing interval of Ciprofloxacin if CrCl < 30ml/min?
Q18-24H
What’s the dosing of Levofloxacin (IV/PO)?
250-720mg daily
500mg, them 250mg daily or 250mg daily
What’s the dosing of Moxifloxacin (IV/PO)?
400mg Q24H
What’s the dosing of Gemifloxacin (PO)?
320mg daily
Black box warning of FQs?
Tendon inflammation and/or rupture (most often in Achilles’ tendon)
Warnings to FQs use?
May prolong QT interval (avoid with class Ia and III antiarrhythmics)
Peripheral neuropathy (with both oral and IV formulations)
CNS effects e.g. Seizures
Hypoglycemia (may be severe and sometimes fatal)
Photosensitivity
Can FQs be used in children?
Avoid in children - risk of arthropathy
FQs SEs?
GI upset/diarrhea
How should Cipro oral suspension NOT be given?
Through a NG or other feeding tube
Don’t refrigerate oral suspension
Which Cipro formulation can be fed through feeding tube?
Cipro IR - crush, mix with water
How should Levofloxacin oral soln be taken? Storage?
On an empty stomach
At room temp
List agents that can chelate FQs
Antacids Didanosine Sucralfate Bile acid resins Mg Al Ca Fe Zn Multivitamin
When do u give Cipro before and after cheating agents?
Cipro - 2hrs b4 or 6hrs after agents
When do u give Levo before and after cheating agents?
2hrs b4 or after
When do u give moxi before and after cheating agents?
4hrs b4 or 8hrs after
List Macrolides agents
Azithromycin (Zithromax, Z-Pak)
Clarithromycin (Biaxin, Biaxin XL, Biaxin XL Pac)
Erythromycin (E.E.S, Ery-Tab, EryPed, Erythrocin)
What’s the brand name of Azithromycin? Macrolide
Zithromax
Z-Pak
What’s the brand name of Clarithromycin? Macrolide
Biaxin
Biaxin XL
Biaxin XL Pac
What’s the brand name of Erythromycin? Macrolide
E.E.S
Ery-Tab
EryPed
Erythrocin
Warning of Macrolides?
QT prolongation (like FQs)
Hepatoxicity
SEs of Macrolide?
GI upset (diarrhea, abdominal pain and cramping esp with Erythromycin)
Storage of Azithromycin oral suspension (Zmax)?
Don’t refrigerate
How do u take Biaxin XL (Clarithromycin)?
With food
Storage of Biaxin (Clarithromycin) oral suspension?
Don’t refrigerate (can gel)
Which Macrolide must be refrigerated? Expiration?
Erythromycin ethylsuccinate (E.E.S) oral granule suspension
Use w/in 10 days
Stability of Erythromycin powder suspension?
Stable at room temp x 35 days
Which Macrolide doesn’t have many clinically significant drug interactions?
Azithromycin
What must be avoided with ALL Macrolides?
With agents that can prolong QT interval
List tetracycline agents
Doxycycline
Minocycline
Tetracycline
How should Oracea (Doxycycline) be taken?
On empty stomach (1hr before or 2hrs after meals)
Take other forms with food to reduce GI irritation
Warnings ass with Tetracycline agents?
Children 8 yrs and under
Pregnancy
Breastfeeding
SEs of Tetracycline agents
GI upset
Photosensitivity
What’s Doxycycline IV to PO conversion ratio?
1:1
Storage of Doxycycline oral suspension
Not to be refrigerated
MOA of Sulfonamides?
Inhibit enzymes of the Folic acid pathway
Individually, they are bacterioSTATIC, but collectively they are bactericidal
List agent under Sulfonamides?
Sulfamethoxazole and Trimethoprim (Bactrim, Septra, Sulfatrim)
What’s the brand name of Sulfamethoxazole and Trimethoprim?
Bactrim
Septra
Sulfatrim
What’s always the ratio of Sulfamethoxazole and Trimethoprim?
5:1 ratio
Eg SMX/TMP 400/80
Indication for Sulfamethoxazole and Trimethoprim (Bactrim, Sulfatrim, Septra)?
Adult female uncomplicated UTI - 1 DS tab bid x 3 days
PCP prophylaxis - 1 DS or SS tab daily
CI to Sulfamethoxazole and Trimethoprim (Bactrim, Sulfatrim, Septra)?
Sulfa allergy
SEs of Sulfamethoxazole and Trimethoprim (Bactrim, Sulfatrim, Septra)?
GI upset (n/v/d)
Skin rxns (rash, SJS, TEN)
Crystalluria (take with 8oz of water)
Photosensitivity
Hyperkalemia
Hypoglycemia
Storage of Bactrim IV? Diluent?
Store at room temp (Bactrim susp too)
Dilute with D5W
Sulfamethoxazole and Trimethoprim (Bactrim, Sulfatrim, Septra) IV to PO?
1:1
Sulfamethoxazole and Trimethoprim (Bactrim, Sulfatrim, Septra) are strong inh of 2C8/9. What med should caution be used with?
Warfarin
MOA of Vancomycin?
Blocks Glycopeptides
Exhibits time-dependent killing and is bacticidal
What’s Vancomycin (Vancocin) DOC for? Dose?
MRSA inf
15-20mg/kg Q8-12H IV
What’s oral Vancomycin used for? Dosing?
C.diff
125-500mg QID Z 10-14 days
SEs of vancomycin?
Infusion rxn/red man syndrome
Nephrotoxicity
What’s Vanco trough (after 4th dose) for Pneumonia, Endocarditis, Osteomyelitis, Menigitis, Bacteremia?
15-20 mcg/mL
What’s Vanco trough (after 4th dose) for other infections?
10-15 mcg/mL
What the max infusion rate for peripheral IV vanco?
Don’t exceed 5 mg/mL
When is an alternative agent considered instead of vanco?
When MIC of organism >= 2 mcg/mL
Coverage of Linezolid?
Most gm-tve bacteria, including MRSA, VRE faecium and faecalis
Approved for pneumonia and uncomplicated/complicated skin and soft-tissue infections including diabetic foot inf and inf caused by Staphylococcus aureus and Strep species and for VRE inf
What’s the brand name of Linezolid?
Zyvox
CI to Linezolid (Zyvox) use?
Concurrent use or w/in 2 wks of MAO inh
Warnings to Linezolid (Zyvox) use?
It’s a weak MAO inh
SEs to Linezolid (Zyvox) use?
Headaches
Diarrhea
What’s the IV to PO conversion of Linezolid (Zyvox)?
1:1
Does Linezolid (Zyvox) req adjustment in renal impairment?
NO!
Storage of Linezolid (Zyvox)?
Room temp
What’s brand name of Quinupristin/Dalfopristin?
Synercid
Whats Quinupristin/Dalfopristin (Synercid) approved for?
Complicated skin and soft-tissue inf caused by Staphylococcus aureus and Streptococcus pyogenes
SEs of Quinupristin/Dalfopristin (Synercid)?
Arthralgias/myalgias (up to 47%)
Infusion rxn, including edema and pain at infusion site (up to 44%)
Phlebitis (40%)
Hyperbilirubinemia (up to 35%)
How should Quinupristin/Dalfopristin (Synercid) be given peripherally?
Must be in a vol of >= 250ml
Mixed with D5W ONLY
What’s Daptomycin brand name?
Cubicin
What’s Daptomycin (Cubicin) approved for?
Complicated skin and soft-tissue inf and staphylococcus aureus bloodstream infections, including right-sided endocarditis
SEs of Daptomycin (Cubicin)?
GI upset (constipation, diarrhea, vomiting)
Increased CPK and myopathy
Monitoring of Daptomycin (Cubicin)?
CPK level weekly