Infectious Diseases II Flashcards
Infuse cefazolin or cefuroxime ___ min before start of surgery
60 min
If a quinolone or Vanc are used, start the infusion ___ min before start of surgery
120 min
Give additional dose/s if surgery is >__ hours, or with major blood loss
3-4h
Post-surgery, abc are not used; d/c within __ hrs
24h
This abx is preferred for most surgeries to prevent MSSA and streptococci infections; what is an alternative if a B-lactam allergy?
Cefazolin, a first generation cephalosporin; or a second-gen ceph: cefuroxime
Alt: clindamycin
In colorectal surgeries, the prophylactic regimen needs to cover skin flora + broad gram (-) and anaerobic organisms found in the gut. Recommended antibiotics:
Cefotetan, cefoxitin, ampicillin/sulbactam, ertapenem, or
metronidazole + (cefazolin or ceftriaxone)
Colorectal surgery prophylaxis, if beta-lactam allergy present
Clindamycin + (AG, quinolone, or Aztreonam) or
metronidazole + (AG or quinolone)
Cardiac or vascular surgery prophylaxis
Cefazolin or cefuroxime
BL allergy: vancomycin or clindamycin
Hip fracture of total joint replacement surgery prophylaxis
Cefazolin
BL allergy: vancomycin or clindamycin
Meningitis- this bacterium is prevalent in neonates, age >50y, and immunocompromised groups and requires additional treatment with ampicillin
Listeria monocytogenes
Common bacteria: S. pneumoniae, Neisseria meningitides, and H. influenzae
Acute bacterial meningitis tx (CA)- Antibiotic durations: - N. meningitidis: - H. influenzae: - S. Pneumoniae: - Listeria Monocytogenes:
Antibiotic durations:
- N. meningitidis: 7 days
- H. influenzae: 7 days
- S. Pneumoniae: 10-14 days
- Listeria Monocytogenes: 21 days
Acute bacterial meningitis tx (CA)-
To prevent neurological complications, _____ can be given prior to or with the first antibiotic dose
20 mins prior to dose, Dexamethasone 0.15mg/kg IV Q6H x 4 days
Treatment for acute Otitis media in children
amoxicillin 80-90mg/kg/day BID OR amox/clav. 90mg/kg/day + 6.4mg/kg/day BID.
If vomiting: ceftriaxone 50mg/kg IM or IV x 1-3days
The high amoxicillin doses are needed to cover most strains of S. pneumoniae
NOTES:
With amox/clav, the formulation with the LEAST amt of clavulanate should be used to dec the risk of diarrhea. 14:1 ratio –> amoxicillin 600mg and clavulanate 42.9mg/5mL
Acute otitis media treatment in kids: when to consider observation?
How many days? & Temp < ??
Age 6-23 months sx?
Age >2y sx?
try observation for 2-3 days if mild ear pain and temp <102.2F and:
- age 6-23 months: sx in one ear only
- age >2y: sx in one or both ears
Pharyngitis treatment
Penicilllin,
amoxicillin
or 1st/2nd gen cephalosporin (cefazolin, cefuroxime, cefotetan) x 10 days
azithromycin x 5 days
Sinusitis treatment
First line: amox/clav
Second line or failure of first: oral 2nd/3rd gen cephalosporin +clindamycin, doxycycline, or a respiratory quinolone (GML)
Influenza treatment
Oseltamivir x 5 days
Baloxavir x 1 dose
Zanamivir inhalation x 5 days
Acute bronchitis treatment
Supportive; abx are not recommended unless pneumonia is present.
The exception is Bordetella pertussis (macrolide - azithromycin, clarithromycin or Bactrim)
Acute bacterial exacerbation of chronic bronchitis can be referred to as a
COPD exacerbation
COPD exacerbation treatment
Supportive treatment (O2, short-acting bronchodilators, IV or PO steroids)
When should abx be given in a COPD exacerbation? (tx is for 5-7 days)
- All of the following: INC dyspnea, INC sputum volume, INC sputum purulence
- INC sputum purulence + 1 additional sx
- mechanically ventilated
What are the preferred antibiotics in a COPD exacerbation?
Amoxicillin/Clavulanate
Azithromycin
Doxycycline
A chest X-ray is the gold standard test for the diagnosis of _____ and will have infiltrates, opacities or consolidations
Community-acquired pneumonia
Most bacterial CAP cases are caused by
S. pneumoniae, H. influenzae, M. Pneumoniae, and possibly C. Pneumoniae
What is the duration for treatment for CAP?
5-7 days
Outpatient treatment of CAP requires an assessment of pt comorbidities and risk factors for drug-resistant pathogens. Patients with comorbidities or immunosuppression require:
broader coverage of possible drug-resistant S. pneumoniae
Step 1 of the outpatient CAP assessment
Look for comorbities (CHF, lung, liver, or renal disease, diabetes, alcoholism, cancer, or asplenia)
Step 2 of the outpatient CAP assessment
Check for MRSA or P.aerugenisoa risk factors, receipt of parenteral abx
Recommended empiric regimen for CAP if patient does not have any comorbidities
Amoxicillin high-dose (1 gram TID), or
Doxycycline, or
Macrolide (azithromycin or clarithromycin) if local pneumococcal resistance is <25%
Recommended empiric regimen for CAP if patient does have comorbidities
Beta-lactam + macrolide or doxycycline
- Amox/Clav or (cefpodoxime, cefdinir, cefuroxime) plus - macrolide or doxycycline
Respiratory quinolone mono therapy (GML)
Inpatient CAP treatment: selection of an empiric regimen is based on:
severity of illness and often includes IV abx initially
Inpatient CAP tx: non-severe/ non-ICU care
- Beta-lactam + macrolide or doxycycline
- preferred beta-lactams: ceftriaxone, cefotaxime, ceftaroline, or amp/sulbactam
- Respiratory quinolone monotherapy
Inpatient CAP tx: severe/ICU care
Beta-lactam + macrolide
Beta-lactam + respiratory quinolone (do NOT use quinolone as mono therapy)
Inpatient CAP tx: concern for MRSA.
Add coverage with:
add coverage with vancomycin or linezolid
Inpatient CAP tx: concern for pseudomonas
Add coverage with:
add coverage with pip/tazo, cefepime, merwpenam, Aztreonam, ceftazidime
Hospital-acquired pneumonia (HAP) has an onset of >___ hours after hospital admission
> 48 hours – HAP is the leading infectious cause of death in ICU patients
Ventilator-associated pneumonia (VAP) occurs > ___ hours after the start of mechanical ventilation
> 48 hours;
rate of VAP can be reduced by:
-proper handwashing
- elevating the head of the bed >30 degrees
- weaning off the ventilator ASAP
- removing NG tubes
- D/C unnecessary stress ulcer prophylaxis
Nosocomial pathogens are common in these infectious situations; the risk for MRSA and MDR gram-negative rods, including P. aeruginosa, acinetobacter spp, enterobacter spp, E.coli and Klebsiella spp is increased in selected cases
HAP & VAP
Empiric Regimen: HAP/VAP
Patient has a low risk for MRSA or MDR pathogens
Choose 1 abx:
Cefepime or
pip/tazo
Empiric Regimen: HAP/VAP
Patient has a risk for MRSA, but low risk of MDR pathogens
Choose 2 abx:
- cefepime + vancomycin
- Meropenem + linezolid
Empiric Regimen: HAP/VAP
Patient has a risk for both MRSA and MDR pathogens (IV abx within the past 90 days)
Choose 3 abx:
- pip/tazo + ciprofloxacin + vancomycin
- cefepime + gentamicin + linezolid
- Positive MRSA nasal swab
- high prevalence of resistant pathogen noted in hospital unit
- IV antibiotics use within the past 90 days
are all high risk of
MRSA or MDR pathogens
List antibiotics for pseudomonas
PSEUDOMONAS –
Pip/tazo
Cefepime, ceftazidime, or ceftolozane/tazo
Quinolones: Levofloxacin or ciprofloxacin
Carbapenems: Imipenem/cilastatin or meropenem
AG: Tobramycin, gentamicin or amikacin (not mono)
Antibiotics for MRSA
Vancomycin or linezolid
Active pulmonary TB is transmitted by
aerosolized droplets (sneezing, coughing, talking) & highly contagious
Presents with cough/hemoptysis, purulent sputum, fever, and night sweats
A false positive TB (TST) test can occur in those who have received what vaccine?
Bacille Calmette-Gurein (BCG) vaccine
Latent TB treatment: shorter regimens are preferred (3-4 months) due to higher completion rates and less risk of
hepatotoxicity
Latent TB treatment: this regimen is once weekly x 12 weeks via directly observed therapy or self-administered
INH and rifapentine once weekly x 12 weeks
Strongly recommended in adults, children >2y, and HIV patients.
NOT for pregnant women.
Latent TB treatment: This regimen is a preferred regimen in children of all ages and HIV-negative adults
Rifampin 600mg daily x 4 months
Drug interactions :(
Latent TB treatment: this regimen is daily x 3 months and can be used in adults, children of all ages, and HIV+ patients
Isoniazid + rifampin daily x 3 months
Latent TB treatment: an alternate regimen-
for HIV- or HIV+ adults and children of all ages, treatment of choice for pregnant women.
Isoniazid 300mg PO daily x 6 months
Isoniazid 300mg PO daily x 9 months (TOC preg)
Active TB must be confirmed with a
sputum culture
M. tuberculosis is an acid-fast bacilli and can be detected using an AFB stain, but SLOW, can take up tp 6 weeks
Active TB treatment: is divided into 2 phases (intensive and continuation).
To avoid resistance, the preferred intensive regimen consists of 4 drugs (2 months):
Rifampin, isoniazid, pyrazinamide, and ethambutol; daily or 5x/week x 2 months (“RIPE” therapy)
Active TB treatment: is divided into 2 phases (intensive and continuation).
In the continuation phase (4 months), treatment is scaled back to 2 drugs:
rifampin and isoniazid daily, 5x per week or 3x per week
based on the drug susceptibility of the isolate.
Can be extended to 7 months if sputum culture remains positive after 2 months of treatment, or if intensive phase treatment did not include pyrazinamide
MDR-TB treatment: preferred drugs include
quinolone (moxi or levo), or injectables (streptomycin, amikacin, or kanamycin) x 24 months
Extremely MDR-TB treatment:
bedaquiline (Sirturo), boxed warnings for QT prolongation and an increased risk of death
Pretomanid + bedaquiline + linezolid, but hepatoxocity, peripheral neuropathy. optic neuropathy, myelosuppresion, QT prolongation
This TB drug can: increase LFTs, hemolytic anemia (+Coombs test) Orange-red discoloration of body secretions Flu-like sx
Rifampin; take on empty stomach
MANY drug interactions, can be replaced with rifabutin in some cases (HIV protease inhibitors)
Rifadin
Rifampin
Rifamate
Rifampin + isoniazid
Rifater
Rifampin + isoniazid + pyrazinamide
Isoniazid is taken with ____ daily to decrease the risk of INH-associated peripheral neuropathy
pyridoxine 25-50mg PO daily
This TB drug has a boxed warning for severe and fatal hepatitis
Can also cause DILE, hemolytic anemia
Isoniazid
This TB drug is contraindicated in acute gout; can increase LFTs, and can cause optic neuritis (dose-related), hallucinations, confusion
Ethambutol
Myambutol
Ethambutol
Noteable interactions of Rifampin include:
protease inhibitors (substitute with rifabutin)
Warfarin (very large dec in INR)
OC (dec efficacy)
DO NOT USE rifampin with
apixiban, rivaroxaban, edoxaban, or dabigatran
Infective endocarditis is diagnosed using what criteria?
Modified Duke Criteria:
- ECG to visualize the vegetation and positive blood cultures
The three most common species of organisms that cause IE are:
staphylococci, streptococci, and Enterococci
IE Empiric treatment often includes:
Vanc and ceftriaxone
This antibiotic is added to the IE regimen for synergy when the infection is more difficult to eradicate (prosthetic valve infections)
Gentamicin, peak levels of 3-4mcg/mL and trough levels <1mcg/mL x 2-6 weeks
IE Abx treatment duration
4-6 weeks of IV antibiotic treatment is required
IE: some bacteria can form a biofilm, especially on prosthetic valves. What abx is used?
Rifampin is used in cases of staphylococcal
IE treatment-
Organism: Viridans group Streptococci
Preferred Abx regimen:
Penicillin or ceftriaxone (+/- gentamicin)
If beta-lactam allergy: use vancomycin monotherapy
IE treatment-
Organism: Staphylococcal (MSSA)
Preferred Abx regimen:
Nafcillin or cephazolin (+/- gentamicin and rifampin if prosthetic valve)
If beta-lactam allergy: use vancomycin (+gentamicin and rifampin if prosthetic valve)
IE treatment-
Organism: Staphylococcal (MRSA)
Preferred Abx regimen:
Vancomycin (+gentamicin and rifampin if prosthetic valve)
IE treatment-
Organism: Enterococci
Preferred Abx regimen:
Penicillin or ampicillin + gentamicin (for both native and prosthetic valve IE)
If beta-lactam allergy, use vancomycin + gentamicin
If VRE, use daptomycin or linezolid
Patients at high risk for IE during dental work + select cardiac conditions including:
Artificial (prosthetic) heart valve or heart valve repaired with artificial material
History of endocarditis
Heart transplant with abnormal heart valve function
Certain congenital heart defects including heart/heart valve disease
Patients at high risk for IE during dental work + select cardiac conditions, adult PO prophylaxis regimen:
amoxicillin 2g 30-60min before dental procedure
Patients at high risk for IE during dental work + select cardiac conditions, adult prophylaxis regimen, unable to take PO meds:
Ampicillin 2g IM/IV or
Cefazolin 1g IM/IV
Patients at high risk for IE during dental work + select cardiac conditions, adult prophylaxis regimen, unable to take PO meds with cilin allergy:
Cephalexin or cefadroxil 2g or
Clindamycin 600mg or
Azithromycin or clarithromycin 500mg
This is an infection of the peritoneal space that often occurs in patients with liver disease
Primary peritonitis, referred to as spontaneous bacterial peritonitis (SBP)
The most likely pathogens of SBP are
Streptococci, enteric gram-negative organisms (Proteus, E. coli, Klebsiella/PEK) and, rarely, anaerobes
Drug of choice for SBP
Ceftriaxone x5-7 days
Alt: ampicillin, gentamicin, or quinolone
Primary or secondary prophylaxis of SBP
Bactrim, ofloxacin, and/or ciprofloxacin
Secondary peritonitis is caused by a traumatic event (ulceration, ischemia, obstruction, surgery). Abscesses are common and should be drained.
The most likely pathogens are:
streptococci, enteric gram-negatives and anaerobes (B. Fragilis).
In more severe cases, coverage of pseudomonas and CAPES organisms may be necessary
An acute inflammation of the gallbladder due to an obstructive stone:
An infection of the common bile duct:
Cholecystitis
Cholangitis
Duration of intra-abdominal treatment (mild, severe, abscess)
4-7 days, mild
7-14 days, severe
>14 days, intra-abdominal abscess
Management of secondary peritonitis and cholangitis - mild to moderate infections
Want to cover:
PEK, anaerobes, streptococci, +/- Enterococci
Management of secondary peritonitis and cholangitis - mild to moderate infections
Therapy:
Possible regimens:
Cefoxitin
Ertapenem
Moxifloxacin
(Cefazolin, cefuroxime, or ceftriaxone) + metronidazole
(Ciprofloxacin or levofloxacin) + metronidazole
Management of secondary peritonitis and cholangitis - high severity/ICU patients
Want to cover:
PEK, CAPES, pseudomonas, anaerobes, Streptococci +/- Enterococci
Management of secondary peritonitis and cholangitis - high severity/ICU patients
Therapy:
Possible regimens:
Carbapenem (not erta)
Pip/tazo
(Cefepime or ceftazidime) + metronidazole
(Cipro or levo) + metronidazole
Cefazolin + (Aztreonam or AG) + metronidazole
SSTI Classifications:
Mild -
Moderate -
Severe-
SSTI Classifications:
Mild - no systemic signs
Moderate - systemic signs (temp >100.4, HR>90, WBC>12k or <4k cells/mm)
Severe- failed PO abx+ incision and drainage if purulent, systemic signs, signs of deeper infection, immunocompromised
Impetigo treatment for minimal lesions & numerous lesions:
Bacteriums: strep, s. aureus (MSSA)
Minimal lesions: topical mupirocin (Bactroban)
Numerous: Cephalexin (Keflex) 250mg PO QID
Follicultis/furuncles/carbuncles treatment
If systemic signs, use abx that cover MSSA:
cephalexin (Keflex) 500mg PO QID
If non-responsive to initial tx, change to a drug with CA-MRSA coverage:
Bactrim DS 1-2 tabs BID
Doxycycline 100mg PO BID
Cellulitis (non-purulent) treatment:
PO Abx must be active against streptococci (+/- MSSA):
Cephalexin 500mg PO QID
Clindamycin 300mg PO QID (if BL allergy
others: penicillin VK, docloxacillin)
x5 days
Abscess (purulent) treatment:
If systemic signs or multiple sites: I&D, culture fluid, use PO Abx that cover CA-MRSA:
Bactrim DS 1-2 tabs BID
Doxycycline 100mg PO BID
Minocycline
Clindamycin
If MSSA –> Keflex
Severe purulent SSTI treatment
duration x 7-14 days
Vancomycin
Daptomycin
Linezolid
Animal bite = amp/sulbactam, amox/clav
Necrotizing Fasciitis treatment
Empiric therapy:
Vanc+beta-lactam (pip/tazo, imipenem/cilastatin, or meropenem)
Treatment of moderate-severe diabetic foot infections/no MRSA coverage needed:
Ampicillin/sulbactam, pip/tazo, a carbapenem (imi/cilastatin, mero, erta) moxifloxacin x7-14 days
Treatment of moderate-severe diabetic foot infections/ MRSA coverage needed:
Vancomycin plus one of the following:
ceftazidime, cefepime, pip/tazo, Aztreonam*, carbapenem (not erta)
Consider adding metronidazole on all the starred
UTI sx: -urgency and frequency - painful urination subrapybic heaviness -blood in urine
Cystitis (lower UTI)
UTI sx:
- flank pain
- fever, malaise
- n/v, abdominal pain
Pyelonephritis (upper UTI)
Acute uncomplicated cystitis treatment
Nitrofurantoin (Macrobid) 100mg PO BID with food x 5 days or Bactrim DS 1 tab PO BID x 3 days or Fosfomycin 3 g x 1 dose
Acute uncomplicated cystitis treatment in pregnancy
Cephalexin, or amoxicillin
treat asx pregnant women x 3-7 days
Acute uncomplicated cystitis treatment; can add this drug to relieve dysuria
phenazopyridine (pyridium) 200mg PO TID x 2 days MAX
Acute uncomplicated pyelonephritis, moderately ill outpatient PO
if local resistant quinolone resistance <10%:
- cipro 500mg PO BID (or cipro ER 1,000mg daily) x 7 days
- levofloxacin 750mg PO daily x 5 dats
If local resistant quinolone resistance >10%
- Ceftriaxone 1g IV/IM x1 or AG extended interval dose IV/IM x1, then continue with a quinolone as above x 5-7 days
- Bactrim x 10-14 days
Acute uncomplicated pyelonephritis, Beverly ill hospitalized patient (IV):
Initial: cipro or levo; gentamicin (+/- ampicillin, ceftriaxone, or pap/tazo); a carbapenem
Step down to PO tx options based on culture & sus
x14 days total (IV + PO)
Complicated UTI Treatment
if local resistant quinolone resistance <10%:
- cipro 500mg PO BID (or cipro ER 1,000mg daily) x 7 days
- levofloxacin 750mg PO daily x 5 days
If local resistant quinolone resistance >10%
- Ceftriaxone 1g IV/IM x1 or AG extended interval dose IV/IM x1, then continue with a quinolone as above x 5-7 days
- Bactrim
Use a carbapenem if ESBL-producing present
x7 days if prompt sx relief
x10-14 days if delayed response
Bacteriuria and Pregnancy treatment
Amoxicillin +/- clavulanate or an oral cephalosporin
Fosfomycin
While avoided in 1st trimester, Macrobid and Bactrim can be used in BL allergy
Traveler’s diarrhea: treatment if dysentery is present
Azithromycin 1000mg PO x1 or 500mg PO dailyx1-3 days
Traveler’s diarrhea: treatment if dysentery is not present
Quinolones (1-3 days) or rifaximin (3 days); loperamide to provide sx relief
Cipro 750mg PO x 1 or 500mg PO BID x 3 days
Levo 500mg PO x 1 or daily x 1-3 days
Olfloxacin 400mg PO x 1 or BID x 3 days
Rifaximin 200mg PO TID x 3 days
C. Dif first episode non severe or severe treatment
vancomycin 125mg PO QID x 10 days, or
Fidaxomicin (Dificid) 200mg PO BID x 10 days
If above tx is not available and episode is non-severe: can use metronidazole 500mg PO TID x 10 days
C. Dif second episode/first recurrence
If metronidazole was used for initial episode: vancomycin 125mg PO QID x 10 days
If Vanc was used for initial episode: fidaxomicin 200mg PO BID x 10 dats
If Vanc or Fidax used first, use tapered and pulse regimen
DOC syphillis
Penicillin G berzathine (Bencillin L-A) 2.4 million units IM x 1
Alt: Doxycycline
DOC Neurosyphilis and congenital syphilis
Pen G aqueous crystalline
Alt: Pen G procaine
DOC gonorrhea
Ceftriaxone 250mg IM + azithromycin 1g PO x1 (or doxycycline)
MONOTHERAPY NOT RECOMMENDED
DOC Chlamydia
Azithromycin 1g PO x1
DOC Bacterial vaginosis
Metronidazole 500mg PO BID x 7 days
or Metronidazole 0.75% gel
or clindamycin 2% gel
DOC trichomoniasis
Metronidazole 2g POx1; (ok in all trimesters)
or
Tinidazole 2g POx1
DOC Genital warts (HPV)
Imiquimod cream (Aldara, Zyclara); tx not required if asx
Gardasil vaccine
Gonorrhea & chlamydia often go together… treatment
(gonorrhea) Ceftriaxone 250mg IM + (chlamydia) azithromycin 1g or doxycycline 100mg BID x7 days
Rickettsia Rickettsii causes Rocky Mountain spotted fever… treatment:
doxycycline 100mg PO/IV BID x 5-7 days (DOC in peds)
Rickettsia typhi causes Typhus… treatment:
Doxy 100mg PO/IV BID x 7 days
Borrelia burgdorferi, borrelia mayonii causes Lyme disease… treatment:
Doxycycline 100mg PO BID x 10-21 days, or
amoxicillin 500mg PO TID x14-21 days, or
Cefuroxime 500mg PO BID x 14-21 days
Ehrlichia chaffeensis causes ehrlichiosis…treatment:
doxycycline 100mg PO/IV BID x ist 7-14 days
Francisella tularensis causes Tularemia… treatment:
Gentamicin or tobramycin 5mg/kg/day IV divided Q8H x7-14 days
Tinea corporis treatment
clotrimazole or another topical fungal
