Selection of Antibiotics for Selection of Antibiotics for Empiric Therapy in Clinical Practice Empiric Therapy in Clinical Practice Linda L. Van Etta, MD, FACP
Dec 26, 2015
Selection of Antibiotics forSelection of Antibiotics for Empiric Therapy in Clinical Practice Empiric Therapy in Clinical Practice
Linda L. Van Etta, MD, FACP
Clinical presentation
Usual pathogens
Sensitivity of pathogen(s) to antibiotics
Drug/host interactions(allergies, renal & liver function,distribution in body, route, cost,duration of therapy)
Please remember:Please remember:
the antibiotic choices listed for each diagnosis are represenative. Different hospitals and clinics may use other agents based on their antibiograms of their organisms or based on their purchasing group
All choices are for empiric therapy. Antibiotic therapy is altered based on culture results
Central Nervous SystemCentral Nervous System
Bacterial Meningitis - Neonate Bacterial Meningitis - Neonate or Infantsor Infants
Clinical presentation: poor feeding, irritability, fever, lethargy
May not have nuchal rigidity
Bacterial Meningitis - Neonate Bacterial Meningitis - Neonate or Infantsor Infants
Strep, group B or D
Enterobacteriaceae
H. influenzae
Listeria
Meningococci
Pneumococci
Bacterial Meningitis - Neonate Bacterial Meningitis - Neonate or Infantsor Infants
Cefotaxime
+ Ampicillin
+ Dexamethasone
Bacterial Meningitis - AdultBacterial Meningitis - Adult
Clinical presentation- headache, fever, confusion
Nuchal rigidity
Bacterial Meningitis - AdultBacterial Meningitis - Adult
Meningococci
Pneumococci
Listeria
Bacterial Meningitis - AdultBacterial Meningitis - Adult
Ceftriaxone or cefotaxime
+ Vancomycin
+ Dexamethasone
Brain AbscessBrain Abscess
Clinical presentation- often stroke like picture with focal neurological deficits, headache
May not be febrile!
Brain AbscessBrain Abscess
Streptococci (60-70%)
Bacteroides (20-40%)
Enterobacteriaceae (25-33%)
Staph aureus (10-15%)
HIV (+) = toxoplasmosis
Brain AbscessBrain Abscess
Ceftriaxone or cefotaxime
+ Metronidazole
EncephalitisEncephalitis
Clinical presentation- confusion, headache, may have fever
Exposure history, season of year
EncephalitisEncephalitis
Herpes simplex arboviruses rabies parasitic
EncephalitisEncephalitis
Acyclovir (HSV) Others- symptomatic treatment only
Respiratory TractRespiratory Tract
Otitis MediaOtitis Media
Clinical presentation- ear pain, may have fever
Tympanic membrane-red, cloudy fluid behind
Otitis MediaOtitis Media
Pneumococci (25-50%)
H. influenzae (15-30%)
B. catarrhalis (3-30%)
Staph aureus (1%)
Group A strep (2%)
“Sterile” (35%, viral)
Otitis Media (choose one)Otitis Media (choose one)
Amoxicillin Erythromycin Trimethoprim/Sulfamethoxazole Amoxicillin/Clavulanic acid Cefuroxime azithromycin 3rd generation oral cephalosporins (Cefaclor)
PharyngitisPharyngitis
Clinical presentation- sore throat, may have fever
PharyngitisPharyngitis
Group A, C, G strep
“Viral”
EBV
Pharyngitis- for lab proven Pharyngitis- for lab proven streptococcal infection (choose streptococcal infection (choose one)one)
Penicillin
Erythromycin
Clindamycin
Treat for 10 days
Pneumonia: Community-acquiredPneumonia: Community-acquired
Clinical presentation- cough, fever, sputum production, occ. dyspnea
Infiltrate on CXR
Pneumonia: Community-acquiredPneumonia: Community-acquired
Pneumococci H. influenzae Mycoplasma pneumoniae Legionella Viral:
Hanta influenza others
Pneumonia: Community-acquired Pneumonia: Community-acquired (choose one)(choose one)
Doxycycline Respiratory fluoroquinolone:
moxifloxacin,gatifloxacin,levofloxacin
Ceftriaxone or Cefotaxime + azithromycin
Piperacillin / tazobactam combined with a resp. fluoroquinolone for severe cases
Influenza-rimantadine or oseltamivir
Pneumonia: Hospital-acquiredPneumonia: Hospital-acquired
Clinical presentation- cough, fever, sputum production developing after >72 hours in the hospital
Pneumonia: Hospital-acquiredPneumonia: Hospital-acquired
Pseudomonas sp.
Klebsiella sp.
Enterobacter sp.
Pneumonia: Hospital-acquiredPneumonia: Hospital-acquired
Cephalosporin, 3rd generation or anti-pseudomonal penicillin
Combined with
Cipro or aminoglycoside
Cystic FibrosisCystic Fibrosis
Pseudomonas aeruginosa*
Staph aureus
Burkholdia (Pseudomonas) cepacia
Cystic FibrosisCystic Fibrosis
Tobramycin- inhaled
AP penicillin or ceftazidime
Ciprofloxacin
(always use 2 drugs)
TMP/sulfa (for Burkholdia)
HIV / AIDS PatientsHIV / AIDS Patients
Clinical presentation
Organisms
Antimicrobial agents
HIV / AIDS PatientsHIV / AIDS Patients
Pneumocystis
(R/O TB)
HIV / AIDS PatientsHIV / AIDS Patients
TMP/sulfa or
Clindamycin + primaquine or
Atovaquone or
Dapsone + trimethoprim
Always use steroids
Genitourinary TractGenitourinary Tract
CystitisCystitis
Clinical presentation- urinary frequency, dysuria, hematuria, urgency
CystitisCystitis
Enterobacteriaceae (E. coli)
Staph saprophyticus
Enterococcus
Cystitis (choose one)Cystitis (choose one)
TMP/SMX
TMP
Ciprofloxacin
3 day treatment course
PyelonephritisPyelonephritis
Clinical presentation- fever, flank or back pain, hematuria
PyelonephritisPyelonephritis
Enterobacteriaceae
Enterococci
Pyelonephritis (choose one)Pyelonephritis (choose one)
TMP/SMX
Cephalosporin (3rd) or AP Pen
Gentamicin
Ciprofloxacin
Treat for 2 weeks
ProstatitisProstatitis
Clinical presentation- perineal pain, low back pain, dysuria, frequency, may have fever and chills
Prostatic tenderness on rectal exam
ProstatitisProstatitis
Enterobacteriaceae
Pseudomonas sp.
Chlamydia and gonoccocus in younger patients
ProstatitisProstatitis
Tetracycline
TMP/SMX
Ciprofloxacin
Ofloxacin
UrethritisUrethritis
Clinical presentation-dysuria, frequency
UrethritisUrethritis
Chlamydia trachomatis
Urethritis (choose one)Urethritis (choose one)
Tetracycline / Doxycycline
Ofloxacin
Azithromycin
Salpingitis (PID)Salpingitis (PID)
Clinical presentation-pelvic or lower abdominal pain, fever
Tenderness and possible mass on pelvic exam
Salpingitis (PID)Salpingitis (PID)
Gonococcus
Chlamydia
Bacteroides
Enterobacteriaceae
Streptococci
Salpingitis (PID)Salpingitis (PID)
Doxycycline + Ceftriaxone + Metronidazole
or Cefoxitin + doxycycline
or
Ofloxacin + metronidazole
Gastrointestinal TractGastrointestinal Tract
Cholecystitis / CholangitisCholecystitis / Cholangitis
Clinical presentation- RUQ pain, fever, nausea
Tenderness in RUQ on exam
Cholecystitis / CholangitisCholecystitis / Cholangitis
Enterobacteriaceae (68%)
Enterococci (14%)
Cl. perfringens (7%)
Bacteroides (10%)
Cholecystitis / CholangitisCholecystitis / Cholangitis
Ceftriaxone + Metronidazole
AP Pen Metronidazole
DiverticulitisDiverticulitis
Clinical presentation-left, lower abdominal pain with fever and diarrhea or bloody stools
Tenderness over LLQ on abdominal exam
DiverticulitisDiverticulitis
Enterobacteriaceae
Bacteroides sp.
Enterococci
Diverticulitis (choose one combo)Diverticulitis (choose one combo)
Gentamicin + Clindamycin
Ceftriaxone + metronidazole
AP Pen + Metronidazole
Amoxacillin/clavulanate
Ciprofloxacin + metronidazole
TMP/SMX + metronidazole
Dysentery / DiarrheaDysentery / DiarrheaSevere, fever, or bloodySevere, fever, or bloody
Clinical presentation- diarrhea, may be bloody, may have fever
Dysentery / DiarrheaDysentery / DiarrheaSevere, fever, or bloodySevere, fever, or bloody
Shigella sp.
Campylobacter jejuni
Salmonella
E. coli 0157:H7
Dysentery / DiarrheaDysentery / DiarrheaSevere, fever, or bloodySevere, fever, or bloody
Ciprofloxacin
TMP/sulfa, erythromycin
Do not treat E coli 0157-increases risk of complications
Dysentery / DiarrheaDysentery / DiarrheaMild or moderateMild or moderate
Clinical presentation – diarrhea, no fever usually, no bloody stools
Dysentery / DiarrheaDysentery / DiarrheaMild or moderateMild or moderate
Enteropathogenic E. coli
Rotaviruses
Norwalk agent
Dysentery / DiarrheaDysentery / DiarrheaMild or moderateMild or moderate
(fluids)
(antimotility agents)
Pseudomembranous enterocolitisPseudomembranous enterocolitis
Clinical presentation-diarrhea, may be bloody
Tenderness on abdominal exam Risk of developing toxic megacolon May develop without antibiotic
exposure, but usually associated
Pseudomembranous enterocolitisPseudomembranous enterocolitis
Clostridium difficile
Pseudomembranous enterocolitisPseudomembranous enterocolitis
Metronidazole
or
Vancomycin (oral)
Bone and Soft Tissue InfectionsBone and Soft Tissue Infections
CellulitisCellulitis
Clinical presentation- swelling, redness, painful soft tissue area, may have fever
CellulitisCellulitis
Group A strep
Staph aureus
Cellulitis (choose one)Cellulitis (choose one)
Clindamycin
Nafcillin or Oxacillin
Cefazolin / Cephalothin
Penicillin G
Septic Arthritis - AdultSeptic Arthritis - Adult
Clinical presentation- painful, swollen, warm joint
Septic Arthritis - AdultSeptic Arthritis - Adult
Staph aureus
Group A strep
Gonococci
Pneumococci
Borrelia burgdorferi (Lyme)
Septic Arthritis - AdultSeptic Arthritis - Adult
Nafcillin or Oxacillin
or
Ceftriaxone (neg. rods) or Cefotaxime
Treat for 4 weeks
Consider Vancomycin if MRSA problem locally
Osteomyelitis (adults)Osteomyelitis (adults)
Clinical presentation- bone pain, may have chronic, draining wound or sinus over the site
Often history of trauma or previous surgery at site
Osteomyelitis (adults)Osteomyelitis (adults)
Staph aureus
Osteomyelitis (adults)-choose oneOsteomyelitis (adults)-choose one
Nafcillin or Oxacillin
Vancomycin (for MRSA concern)
Cephalothin (1st generation)
Clindamycin
Puncture FootPuncture Foot
Pseudomonas aeruginosa
Puncture FootPuncture Foot
AP Pen or Ceftazidime +
APAG or FQ
Bacterial EndocarditisBacterial Endocarditis
Bacterial Endocarditis - AcuteBacterial Endocarditis - Acute
Clinical presentation- fever, night sweats
Heart murmur on exam
Bacterial Endocarditis - AcuteBacterial Endocarditis - Acute
Viridans strep (30-40%)
Staph aureus (20-35%)
Group D strep (5-18%)
Bacterial Endocarditis - AcuteBacterial Endocarditis - Acute
Penicillin G or Ampicillin +gentamicin
Nafcillin +rifampin
Vancomycin
Case studiesCase studies
7 y.o. Girl7 y.o. Girl
Chief Complaint Dysuria and urinary frequency x 2 days No fever, flank pain, trauma, hematuria (gross),
or emesis
Physical Exam Mild suprapubic tenderness T-37.0, P-71
7 yr old girl7 yr old girl
Dx?
Tests?
7 y.o. Girl7 y.o. Girl
UA 100-200 WBC/hpf 5-10 RBC/hpf
Urine Gram Stain 15-25 gram negative rods/hpf
Specimen sent for culture
RX: ____________________
7 y.o. Girl7 y.o. Girl
Culture Grew
>100,000 ml E. coli sensitive to amoxicillin, sulfa, cefazolin, ciprofloxacin
7 y.o. Girl7 y.o. Girl
Recommended
IVP
Voiding cystogram
Cystoscopy
27 y.o. Male Pediatric Resident27 y.o. Male Pediatric Resident
Chief Complaint Cough, chest pain, fever x 2 days, headache
History of Present Illness “URI” symptoms for several days Developed nonproductive cough and fever Day before admission noted right-sided
pleuritic pain and cough productive of blood-tinged sputum
27 y.o. Male Pediatric Resident27 y.o. Male Pediatric Resident
Physical Exam
Moderately ill
VSS, Temp - 103ºF
Chest - fine, moist rales RLL posteriorly
27 yr old male pediatric resident27 yr old male pediatric resident
Dx? Tests?
27 yr old pediatric resident27 yr old pediatric resident
WBC-8,700/ul Legionella urinary antigen-neg Pneumococal urinary antigen-neg C-reactive protein-4.5 mg/dL
27 y.o. Male Pediatric Resident27 y.o. Male Pediatric Resident
Gram Stain (sputum) Many PMNs Few (+) cocci Occasional (-) rod
RX: ___________________
27 y.o. Male Pediatric Resident27 y.o. Male Pediatric Resident
Sputum culture - grew normal flora
54 y.o. Female54 y.o. Female
Chief Complaint Pain in right leg, chills and fever
History of Present Illness Hx of phlebitis, now has chronic edema, especially
right leg 18 hours prior to admission noted pain in leg that
became progressively worse Few hours later noted redness, swelling & blisters;
then chills and fever developed
54 y.o. Female54 y.o. Female
Physical Exam VSS, Temp 102.6ºF Right leg indurated, erythematous, swollen,
large bullae from ankle to knee
54 yr old female54 yr old female
Dx? Tests?
54 yr old female54 yr old female
WBC-14,600 CRP-18.2 Blood cultures x 2-results pending Wound culture-moderate WBC, moderate
Gram + cocci
Rx_____________
54 y.o. Female54 y.o. Female
Blood culture and culture of skin lesions grew Group A beta hemolytic streptococci
Patient improved with parenteral clindamycin and warm packs
69 y.o. Male69 y.o. Male
Chief Complaint Fever, cough, pain in left leg
History of Present Illness 10 days PTA fever and cough productive
of purulent sputum 8 days PTA severe pain left knee 7 days PTA knee swollen, very hot and
tender
69 y.o. Male69 y.o. Male
Physical Exam
Acutely ill, dyspneic
VSS, Temp – 103.6ºF
Chest - rales left mid lung field, posteriorly
Left knee - swollen, tender, erythematous, hot
69 yr old male69 yr old male
Dx? Tests?
69 yr old male69 yr old male
WBC-17.600 CRP-25.6 Blood cultures x 2 –results pending Creatinine-1.1 Other tests?
69 y.o. Male69 y.o. Male
Arthrocentesis Turbid fluid 70,000 WBC, 95% PMNs Sugar - 15 mg% Protein - 6 grams %
Gram Stain (+) cocci, in pairs
RX: __________________
69 y.o. Male69 y.o. Male
Blood cultures and synovial fluid grew
Streptococcus pneumoniae
Patient was treated with ceftriaxone 2 gms IV q 24 hrs for 4 weeks
56 yr old male56 yr old male
Chief complaint : abdominal pain and fever
HPI: 3 days of increasing abdominal pain, mild diarrhea, and fever to 100.4
56 yr old male56 yr old male
P.E: T-38, BP-130/72, P-96, R-19 Lungs-clear, CV- RR, no murmur Abdomen- tender with rebound diffusely,
absent bowel sounds
56 yr old male56 yr old male
Dx? Tests?
56 yr old male56 yr old male
WBC-18,600 with 92% neutrophils Creatinine-1.8, BUN-34 AST-24 Other tests?
56 yr old male56 yr old male
CT abdomen/pelvis-diverticula of sigmoid colon with inflammatory changes, paracolonic inflammatory mass, and peritoneal fluid.
Rx:______________
56 yr old male56 yr old male
Blood cultures were negative Peritoneal cultures grew-E coli, Bacteroides
species, Fusobacterium species, Enterococcus faecalis, and Enterobacter cloacae
56 yr old male56 yr old male
Patient recovered after surgical resection of the sigmoid colon with formation of a colostomy and peritoneal irrigation combined with
Antibiotic therapy- metronidazole combined with ciprofloxacin and piperacillin/tazobactam for 10 days
28 yr old female28 yr old female
Chief complaint: confusion HPI: lives alone, found by her friend in bed at
home this morning-confused, weak, unsteady on feet, speaking in nonsensical sentences
28 yr old female28 yr old female
Physical exam: T-37, BP 122/63. P-73, R-16 Lungs-clear, CV-RR, no murmur, Abd-soft,
non-tender Neuro-neck supple, expressive aphasia,
DTRs-equal and reactive, toes down-going bilaterally
28 yr old female28 yr old female
Dx? Tests?
28 yr old female28 yr old female
CSF- WBC 34 with 72% mononuclear, RBC 75, glucose-64, protein-45
CSF- gram stain – few WBC, no bacteria seen
CT brain- normal Additional tests?
28 yr old female28 yr old female
MRI brain- enhancement of the temporal region on the left
Rx:__________________
28 yr old female28 yr old female
CSF PCR was positive for herpes simplex
Patient recovered with intravenous acyclovir-10 mg/kg IV q 8 hrs for 21 days