Infectious Disease II - Bacterial Infections Flashcards Preview

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Flashcards in Infectious Disease II - Bacterial Infections Deck (70)
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1
Q

Name common pathogens in bone and joint infections.

A

s. aureus, s. epi, strep, n. gono

2
Q

Name common pathogens in UTIs.

A

E. coli, kleb, proteus, strep, enterococci, s. saprophyticus

3
Q

Name common lower respiratory pathogens (community and hospital).

A

community: atypicals, strep pneumo, h. flu, possibly enteric GNRs
hospital: pseudomonas, enteric GNR, s. aureus, strep pneumo

4
Q

Name common meningitis pathogens.

A

Listeria (in very young and elderly), neisseria, GBS (young), E. coli (young), s. pneumo, h. flu

5
Q

Name common upper respiratory pathogens.

A

s. pneumo/pyo, h. flu, moraxella

6
Q

Name common endocarditis pathogens.

A

s. aureus, s. epi, strep, enterococci

7
Q

Name common intra-abdominal pathogens.

A

enteric GNR, enterococci, strep, bacteroides

8
Q

Name common SSTI pathogens.

A

staph, strep, GNR (diabetics)

9
Q

How long before surgery should preop abx be hung?

A

Most antibiotics should be hung 1 hour before surgery, except FQs and vanc, which should be 2 hours before.

10
Q

Which types of operations require additional coverage outside of skin flora? What additional bugs should be considered?

A

colorectal procedures and hysterectomies require anaerobic and GNR coverage

11
Q

Which antibiotics are most frequently used in preop ppxs?

A

For routine procedures that don’t warrant additional pathogen coverage, cefazolin, cefuroxime, and vanc are the most common choices. For anaerobic/GNR coverage, cefotetan, metronidazole, amp/sulb, cefoxitin, ertapenem, and ceftriaxone are options.

12
Q

What are the drugs and doses used for meningitis empirically in most patients (2-50 years old)?

A

To cover neisseria and strep pneumo, high doses of vanc and ceftriaxone are used.

30-45 mg/kg/day vanc and 2g q12h ceftriaxone

13
Q

Which medication is used to cover for Listeria?

A

ampicillin

14
Q

What is the empiric meningitis regimen for adults aged >50 years?

A

ceftriaxone, vanc, and ampicillin covering strep, neisseria, listeria, and GNB

15
Q

What is the empiric meningitis regimen for neonates?

A

ampicillin with cefotaxime or gent

16
Q

What are the preferred drugs and doses for acute otitis media treatment? How long should you treat?

A

amoxicillin 90 mg/kg/day or augmentin 90 mg/kg/day

use the lowest amount of clavulanate possible to avoid diarrhea SE

Tx duration is usually 5-7 days for mild/moderate infections, and 10 days for severe.

17
Q

When would it be a good idea to use augmentin over amoxicillin in a child presenting with AOM?

A

if the child has had amoxicillin in the last 30 days

18
Q

What are the criteria for anti-infectives in suspected pharyngitis? sinusitis?

A

pharyngitis - positive rapid antigen test

sinusitis - either 10 days of symptoms or 3 days of severe symptoms

19
Q

What are first-line treatments for pharyngitis and sinusitis in patients that meet anti-infective criteria?

A

pharyngitis - penicillin or 1/2 gen ceph

sinusitis - augmentin, if tx failure or severe pen allergy cna use clinda, resp FQ, or doxy

20
Q

How long should you treat pharyngitis? sinusitis?

A

pharyngitis is treated for 10 days unless using azith (5d)

sinusitis initial tx is 5-7 days, may require 7-10 if treatment failure

21
Q

How is acute bronchitis not related to a COPD exacerbation treated?

A

NOT with antibiotics, as the cause is often not bacterial. ONLY consider antibiotics in severe cases. Supportive care (hydration, antipyretics, antitussives) recommended.

22
Q

When are antibiotics warranted in acute bronchitis?

A

1) when related to COPD exacerbation and meets specific criteria (another question)
2) when pneumonia is suspected
3) when whooping cough (Bordatella) is confirmed

23
Q

What are the criteria for antibiotic use in acute bacterial exacerbations of chronic bronchitis?

A

increased sputum purulence plus either increased sputum production or increased dyspnea

24
Q

In a health patient with no recent antibiotic use, name two drugs most commonly used to treat outpatient CAP.

A

1) azithromycin

2) doxycycline

25
Q

What characteristics should you look for in a patient history that would suggest combination or broader spectrum monotherapy would be necessary for outpatient CAP?

A

1) comorbidities like CHF, DM, liver/renal disease, malignancy, asplenia
2) recent antibiotic use (last 90 days)
3) immunocompromised

26
Q

What agents should be used in patients the require more extensive treatment for outpatient CAP?

A

1) beta-lactam and macrolide
2) resp FQ monotherapy
3) beta-lactam and doxy

27
Q

What are the preferred beta-lactams in outpatient CAP?

A

high dose amoxicillin (1g TID), cefpodoxime, augmentin, cefdinir

28
Q

What are the preferred beta-lactams for inpatient CAP?

A

ceftriaxone, cefotaxime

29
Q

When should a resp FQ be used in inpatient CAP?

A

Due to safety concerns, FQs should be reserved for patients with severe penicillin allergies.

30
Q

What are some risk factors for MDR pathogens and MRSA in patients with HAP/VAP?

A

1) IV abx use within the last 90 days
2) high prevalence of MRSA in hospital unit
3) hospitalization of at least 5 days prior to ventilation
4) septic shock at the time of VAP onset
5) acute RRT at time of VAP onset

31
Q

When is double coverage of pseudomonas warranted?

A

Use two drugs that cover pseudomonas when the patient has a high risk of mortality, has had IV abx in the last 90 days, or has MDR risk factors for HAP/VAP.

32
Q

Which drugs will cover pseudomonas and MSSA in patients without risk factors for MDR or MRSA?

A

cefepime, levo, pip/tazo, meropenem

33
Q

This class of drugs will only be used for pseudomonas as combination therapy - they are not options for single coverage of pseudomonas.

A

aminoglycosides

34
Q

If a patient has risk factors for MRSA, they will have one of these two drugs on board:

A

vanc or linezolid

35
Q

What are the 6 pseudomonas monotherapy options?

A

cefepime, ceftazidime, aztreonam, levofloxacin, pip/tazo, meropenem

36
Q

What is the general duration of treatment for HAP/VAP?

A

7 days, longer or shorter based on radiologic/lab/clinical findings

37
Q

two most important rifampin pearls/counseling points

A

1) take on an empty stomach - food decreases absorption

2) will cause bodily secretions to be stained orange, which can stain contact lenses, clothes, etc.

38
Q

Which drug may be substituted for rifampin in patients that must avoid drug interactions?

A

rifabutin (dosed at half rifampin dose - 5 mg/kg/day)

39
Q

Which drugs are part of the induction regimen for TB?

A

rifampin 10 mg/kg daily, isoniazid, 5 mg/kg daily, pyrazinamide 25 mg/kg daily, and ethambutol 20 mg/kg daily

40
Q

Describe the treatment approach for TB.

A

Induction and continuation phases. induction is usually 2 months, and continuation is usually 4 but may be prolonged. the most common reason to prolong the continuation phase to 7 months is a positive sputum culture at the end of the induction phase. higher doses of continuation drugs may be given less frequently (2-3x/week) and directly observed if adherence is an issue.

41
Q

two most important pearls/counseling points for isoniazid

A

1) take on empty stomach

2) warning for peripheral neuropathy - supplementation with pyrodoxine 25 mg daily can help prevent

42
Q

What is a side effect common to all TB drugs that must be monitored for?

A

liver wreckage

43
Q

adverse effects of isoniazid

A

1) hyperglycemia
2) GI upset
3) hemolytic anemia
4) drug induced lupus erythematosus

44
Q

adverse effects of pyrazinamide

A

1) hyperuricemia
2) GI upset
3) rash
4) arthralgia/myalgia

45
Q

adverse effects of ethambutol

A

1) optic neuritis - contraindicated if previously existing

2) confusion/hallucinations

46
Q

Which two TB drugs must be given with a longer dosing interval in renal impairment?

A

pyrazinamide (CrCl < 30) and ethambutol (CrCl < 50)

47
Q

most common causative organisms in endocarditis

A

staph, strep, enterococci, viridans strep

48
Q

What patient anatomical characteristics guide endocarditis treatment?

A

The duration is mainly driven by the level of resistance of the organism and the valve type (tissue vs. prosthetic). Antibiotic choice is determined by organism and susceptibility.

49
Q

What is the recommended duration of therapy for aminoglycosides when used for synergy?

A

2 weeks

50
Q

Give the most common endocarditis prophylaxis regimen for all patients and options for penicillin allergic patients.

A

amoxicillin 2g one hour before procedure

clindamycin 600 mg or azithromycin 500 mg for penicillin allergy

51
Q

Describe the difference between primary and secondary peritonitis.

A

Primary peritonitis is most frequently caused by liver disease. Secondary peritonitis usually follows abdominal trauma (ulceration, ischemia, surgery).

52
Q

What are the most common causative organisms in intra-abdominal infections?

A

anaerobes, strep, and enteric gram negs

note: anaerobes much less common in primary than secondary peritonitis

53
Q

What is the usual treatment duration for intra-abdominal infections?

A

4-7 days, longer if more severe or abscesses are present

54
Q

What additional organisms should you cover for in critically ill patients with intra-abdominal infections?

A

pseudomonas, CAPES

55
Q

What are the most common agents used for typical, non critically ill patients with intra-abdominal infections?

A

cefoxitin (not enterococci), moxi (moderate activity for enterococci), ertapenem, cephalosporin/FQ + metronidazole

56
Q

What are the 3 most common SSTIs and the treatments of choice for each?

A

1) impetigo (staph and strep) - treated with topical mupirocin or systemic Keflex if numerous widespread lesions
2) folliculitis and related (staph including MRSA) - Keflex for MSSA, Bactrim or doxy if suspect CA-MRSA
3) cellulitis (staph, strep) - Keflex or penicillin if mild, bactrim or doxy of suspect CA-MRSA

57
Q

For how long should you treat a diabetic foot infection?

A

usually 7-14 days, weeks if deeper infection present such as osteo

58
Q

Which patients would meet criteria for an uncomplicated UTI?

A

nonpregnant premenopausal female patients with no urologic abnormalities

59
Q

Which patients would be classified as a complicated UTI?

A

all males with UTI, pregnant females, catheter-related UTIs

60
Q

two most common treatments for uncomplicated UTIs

A

1) macrobid 100 BID WITH FOOD

2) Bactrim DS BID if CrCl 30-60

61
Q

most common pathogens for UTI

A

E. Coli, E. Coli, E. Coli, Klebsiella, Proteus, enterococci

62
Q

Which drug class is preferred for pyelonephritis or complicated UTIs?

A

FQs (except moxi)

If quinolone resistance is more than 10%, give a single dose of ceftriaxone or extended interval AG followed by quinolone. can also use bactrim or a beta-lactam for 14 days

63
Q

In which group of patients will asymptomatic bacteruria always be treated? What is the UA cutoff of bacteria/mL?

A

Bacteruria is defined as at least 10^5 bacteria/mL on a UA. Treat all cases in pregnant women, as lack of treatment can be harmful to the fetus.

64
Q

preferred tx for asymptomatic bacteruria in pregnant women

A

augmentin or oral cephalosporin

65
Q

What are the ACOG recommendations for pregnant patients with penicillin allergies that get a UTI?

A

nitrofurantoin and bactrim have recommendations per ACOG, but have limited use. Both should be avoided in the 1st and 3rd trimesters.

66
Q

How long should asymptomatic bacteruria be treated in pregnant women?

A

3-7 days

67
Q

What are the two recommended treatment options for C. diff initial episode?

A

vanc 125mg PO QID or fidaxomycin 200 mg BID

both are 10 days duration

68
Q

In recurrent C. diff, what are the treatment options if vancomycin was used initially? fidaxomycin? metronidazole?

A

vanc - fidaxomycin 200 mg BID or vanc tapered/pulsed regimen
fidax - vanc tapered/pulsed regimen
metro - vanc 125 mg QID

69
Q

What regimens are available for patients that present with fulminant or complicated C. diff infections?

A

vanc 500 mg QID or metronidazole 500 mg IV TID

70
Q

State the preferred treatments for each stage of syphilis (primary/early, secondary, tertiary/late).

A

primary and secondary have very similar recommendations - IM benzathine penicillin 2.4 million U x1 dose for primary and weekly x3 doses for secondary