Chapter 23: Infectious Diseases II Flashcards
Perioperative Abx Selection
- Cefazolin (is preferred to prevent MSSA and streptococci infections)
- Clindamycin is alt if beta-lactam allergy
- Vanco if MRSA colonization risk is present
Perioperative Abx Selection: cardiac or vascular surgeries
- Cefazolin or cefuroxime
- Vanco or clinda if beta-lactam allergy
Perioperative Abx Selection: hip fracture repairs / total joint replacments
- Cefazolin
- Vanco or clinda if beta-lactam allergy
Perioperative Abx Selection: Colon (colorectal) or other surgeries involving the abdominal space
Cefotetan, cefoxitin, amp/sulbactam, ertapenem
or
Metronidazole + (cefazolin or ceftriaxone)
Perioperative Abx Selection: Colon (colorectal) or other surgeries involving the abdominal space
Beta-lactam allergy
Clinda + (aminoglycosides, quinolones, or aztreonam)
or
Metronidazole + (aminoglycoside or quinolones)
Meningitis empiric tx: neonate (<1month)
Ampicillin (for listeria coverage) \+ Cefotaxime (NO ceftriaxone) or Gentamicin
Meningitis empiric tx: age 1 month to 50 years
Ceftriaxone or cefotaxime
+
Vanco
Meningitis empiric tx: >50 years or immunocompromised
Ampicillin (for listeria coverage) \+ ceftriaxone or cefotaxime \+ vanco
Acute Otitis Media (AOM) Abx therapy first-line
Amox 80-90mg/kg/day in 2 divided doses
or
Amox/clav 90mg/kg/day (6.4mg/kg/day clav) in 2 divided doses
or
Ceftriaxone 50mg/kg IM or IV for 1 or 3 days (if vomiting and unable to tolerate po)
Acute Otitis Media (AOM) Abx alternative therapy (beta-lactam allergy)
Cefdinir 14mg/kg/day in 1 or 2 doses
Cefuroxime 30mg/kg/day in 2 divided doses
Cefpodoxime 10mg/kg/day in 2 divided doses
Ceftriaxone 50mg/kg IM/IV qd for 1 or 3 days
Common Cold etiology, symptoms, criteria for anti-infective, and tx options
Etiology: respiratory viruses (rhinovirus, seasonal coronavirus)
Symptoms: sneezing, runny nose, cough
Anti-infective: none
Tx: OTC cold medications
Influenza etiology, symptoms, criteria for anti-infective, and tx options
Etiology: influenza virus
Symptoms: sudden onset fever, chills, fatigue, body aches
Criteria for anti-infective: <48 hours since symptom onset
Tx: oseltamivir x 5 days, baloxavir marboxil x 1 dose, zanamivir inh x 5 days
Pharyngitis etiology, symptoms, criteria for anti-infective, and tx options
Etiology: respiratory viruses, S. pyogenes
Symptoms: “strep throat,” sore throat, swollen lymph nodes, white patches on tonsils
Criteria for anti-infective: + rapid antigen diagnostic test
Tx: penicillin or amox or 1st or 2nd gen cephalosporin
Sinusitis etiology, symptoms, criteria for anti-infective, and tx options
S. pneumoniae, H. influenzae, and M. catarrhalis; Staphylococci, anaerobes, gram-neg rods
Symptoms: nasal congestion, purulent nasal discharge, facial/ear/dental pain, headache
Criteria for tx: >=10 days w/symptoms; >=3 days of severe symptoms
Tx: amox/clav
Bronchitis
Causes can include bordetella pertussis (whooping cough), S. pneumoniae, Mycoplasma pneumoniae, H. influenzae
Abx only indicated if whooping cough then treat with azith, clarith, or SMX/TMP
Acute Bacterial Exacerbation of Chronic Bronchitis
ABECB Supportive measures (O2, short-acting bronchodilators, IV or PO steroids) Then abx for 5-7 days if one of the following are met: increased dyspnea, increased sputum volume, increased sputum purulence; mechanically ventilated Preferred abx: amox/clav, azith, doxy
CAP symptoms and diagnostics
- Fever
- Cough with purulent sputum
- Rales (crackling noises in lungs)
- Tachypnea (increased resp rate)
Chest x-ray is gold standard for diagnostics and will have inflitrates, opacities, or consolidation
CAP pathogens
S. pneumoniae, H. influenzae, M. pneumoniae and possibly C. pneumoniae
Outpatient CAP Tx: Category 1
(no comorbidities) Amox high dose (1gm tid) or Doxy or Macrolide (azith or clarith) if local pneumococcal resistance is <25%
Outpatient CAP Tx: Category 2
Comorbidities present (chronic heart, liver, lung, or renal disease; diabetes, alcoholism, malignancy or asplenia)
- Beta-lactam + macrolide or doxy
e. g amox/clav or cephalosporin + macrolide or doxy - Respiratory quinolone monotherapy (levoflox, gemiflox, mociflox)
Inpatient CAP Tx: Non-severe (non-icu)
-Beta-lactam + macrolide or doxy
(preferred beta-lactams: ceftriaxone, cefotaxime, ceftaroline, or amp/sulb)
-Respiratory quinolone monotherapy
Inpatient CAP Tx: Severe (ICU typically required)
- Beta-lactam + macrolide
- Beta-lactam + respiratory quinolone (do not use quinolone monotherapy)
Inpatient CAP Tx: if risk factors for Pseudomonas and/or MRSA add on
MRSA: add coverage with vanco or linezolid
Pseudomonas: add coverage with pip/tazo, cefepime, ceftazidime, imipenem/cilastatin, meropenem or aztreonam
HAP and VAP onset
> 48 hours after hospital admission
>48 hours after start of mechanical ventilation
Common Pathogens in HAP and VAP
- MRSA
- MDR gram-negative rods: P. aeruginosa, Acinetobacter spp. Enterobacter spp. E. coli, and Klebsiella spp.
HAP/VAP Empiric Regimen: Identifying Risk for MRSA and MDR
- Positive MRSA nasal swan
- High prevalence (>10%) of pathogen resistance to any single agent noted in hospital unit
- IV abx within the last 90 days
HAP/VAP Empiric Regimen: all patients need
Coverage for Pseudomonas and MSSA
E.g cefepime and pip/tazo
HAP/VAP Empiric Regimen: MRSA
- Vanco
- Linezolid
For example:
cefepime + vanco
Meropenem + linezolid
HAP/VAP Empiric Regimen: Pseudomonas if risk for MDR pathogens
If patient has risk for MDR pathogens then typically has risk for MRSA. Requires 3 drug regimen)
E.G pip/tazo + cipro + vanco
cefepime + linezolid + gentamicin
HAP/VAP Empiric Regimen: Abx for pseudomonas
- pip/tazo
- cefepime, ceftazidime, or ceftolazone/tazobactam
- levofloxacin or ciprofloxacin
- imipenem/cilastatin or meropenem
- aztreonam
- tobramycin, gentamicin, amikacin (these are always used with another antipseudomonal drug)
- colistimethate or polymixin b
HAP/VAP Empiric Regimen: Abx for MRSA
Vanco
Linezolid
Latent TB: Preferred Regimens
- Isoniazid (INH) and rifapentine qweek x12weeks (do not use on pregnant women) (for >2 children and adults)
- Rifampin 600 qd x4 months (children of all ages and HIV pts)
- INH and rifampin qd x3months (adults, children of all ages and HIV)
Latent TB: alternate regimens
INH 300mg qd for 6 months or 9 months (HIV positive and negative patients of all ages)
Active TB Tx
RIPE (Intensive therapy for 2 months) R- rifampin I- INH P- pyrazinamide E- ethambutol
Continuation with two drugs (usually rifampin and INH) for remaining 4 months
Rifampin SE, notes
SE: increased LFTs, hemolytic anemia, flu-like syndrome, orange-red discoloration of body secretions (sputum, urine, sweat, tears, teeth) can stain contact lenses, clothing
Note: rifampin has many drug interactions, in some cases rifabutin can replace it
Isoniazid warnings, SE
Warnings: peripheral neuropathy (supplement with pyridoxine [b6] 25-50mg po qd to decrease risk)
SE: increased LFTs, DILE, hemolytic anemia
Pyrazinamide CI, SE
CI: acute gout
SE: increased LFTs, hyperuricemia/gout
Ethambutol SE
SE: increased LFTs, optic neuritis (dose-related), confusion, hallucinations
Rifampin Drug Interactions
- Protease inhibitors (substitute rifabutin)
- Warfarin (very large decrease in INR)
- Oral contraceptive (decrease efficacy)
- Do not use with apixaban, rivaroxaban, edoxaban, or dabigatran
Infective Endocarditis Diagnosis
Modified Duke Criteria which includes an echocardiogram to visualize vegetation and positive blood cultures
Infective Endocarditis Most Common Pathogens
Streptococci, staphylococci, and enterococci
Infective Endocarditis Tx
- Generally Vanco and ceftriaxone. Sometime Gentamicin is added for synergy
- Usually tx is is 4-6 weeks of IV abx
Infective Endocarditis Gentamycin dosing
Target peak levels of 3-4mcg/ml and trough levels of <1mcg/ml
Patients at high-risk for Infective Endocarditis after Dental Work
- artificial (prosthetic) heart valve or heart valve repaired with artificial material
- Hx of endocarditis
- Heart transplant with abnormal heart valve function
- Certain congenital heart defects including heart/heart valve disease
Infective Endocarditis Dental Work Prophylaxis
PO: amoxicillin 2 grams 30-60 minutes before dental procedure
*If unable allergic to PCN: clindamycin 600mg or azith or clarith 500mg
TX for SBP
Ceftriaxone for 5-7 days
SMX/TMP or cipro can be used for primary or secondary prophylaxis
Secondary peritonitis causes
Usually caused by a traumatic events and the most likely pathogens are streptococci, enteric gram-neg and anaerobes (b. frag)
Management of secondary peritonitis and cholangitis: mild to moderate infections
Coverage for PEK, anaerobes, streptococci and enterococci
Examples: Cefoxitin, ertapenem, moxifloxacin, (cefazolin, cefuroxime, or ceftriaxone) + metronidazole, (cipro or levoflox) + metronidazole
Management of secondary peritonitis and cholangitis:: high-severity infections (ICU)
Coverage for PEK, CAPES, pseudomonas, anaerobes, streptococci+-enterococci
Examples: Carbapenems (except ertapenem), pip/tazo,, (cefepime or ceftazidime) + metronidazole, (cipro or levo) + metronidazole, Cefazolin + (aztreonam or aminoglycoside) + metronidzolw
Superficial SSTI
- Impetigo
- Furuncles
- Carbuncles
Nonpurulent that penetrate the subq tissue
Cellulitis
Purulent
Abscess
Mild, Moderate, Severe SSTI
Mild- no systemic signs
Moderate- systemic signs (fever >100/4, HR > 90bpm, WBC >12,000 or <4,000
Severe- failed oral abx + incision and drainage, systemic signs, signs of deeper infection, or immunocompromised
Impetigo tx
Topical mupirocin
If systemic needed use cephalexin 250mg po qid
Folliculitis/furuncles/carbuncles Tx
If systemic signs: cephalexin
If non-responsive change to drug with CA-MRSA coverage: SMP/TXM, doxycycline
Cellulitis (non-purulent)
Cephalexin
Abscess
Mild: I and D
Moderate: SMX/TMP, Doxycycline
Severe purulent ssti
IV abx with MRSA
- vanco (trough goal 10-15)
- daptomycin
- linezolid
Necrotizing Fascitis
Empiric therapy is broad
Vanco + beta lactam (pip/tazo, imipenem/cilastatin or meropenem)
Diabetic Foot Infections Monotherapy
When no MRSA coverage needed
-Amp/sulbactam, pip/tazo, carbapenems, tigecycline, or moxifloxacin
Diabetic Foot Infection Combo Therapy
When MRSA and Pseudomonas
Vanco +
ceftazidime, cefipime, pip/tazo, aztreonam, or a carbapenem (except ertapenem)
Acute Uncomplicated Cystitis Tx:
Nitrofurantoin (macrobid) 1 po bid f5d
SMX/TMP ds 1 po bid f3d
Acute Uncomplicated Cystitis in pregnancy
Cephalexin
Amoxicillin
Acute Pyelonephritis
- If local quinolone resistance is <10%: ciprofloxacin, levofloxacin
- If local quinolone resistance is >10%: ceftriaxone, ertapenem, aminoglycoside
Complicated UTI
Carbapenem if ESBL are present
Traveler’s Diarrhea Tx
In fever, bloody stool, pregnant or pediatric: Azithromycin 500mg qd f1-3 days
If no bloody stool choose quinolone or rifaximin
Syphilis Tx
Pen G (Bicillin l-a) (desensitize for pregnancy or hiv positive) Alternative: doxycycline
Gonorrhea Tx
Cefrtriaxone 500mg im once; if chlamydia is not excluded and doxycyline
Chlamydia
Doxy (100mg po bid for 7 day) or azith (1 gram po once)
Bacterial Vaginosis
Metronidazole po or pv
Trichomonias
metronidazole 2gm po once
Genital warts
imiquimod
Rocky Mountain Spotted Fever
Doxycyline (also preferred in children)
