Transcript Antibiotics for Pediatric Diseases

Case #1
An 8-year-old boy is seen in February
because of fever, headache, sore
throat, and malaise. He’s had no
rhinorrhea, cough, or hoarseness.
Physical examination reveals a
temperature of 103.5, exudative
pharyngitis, and tender cervical
adenopathy.
How will you treat him?
Is penicillin still the drug of choice for
treatment of streptococcal pharygitis?
• AAP recommends oral penicillin V 23 times daily for 10 days, a single
dose of benzathine penicillin, or
amoxicillin 250 mg/kg tid for 10
days
• Larger doses of penicillin once daily
result in more relapses*
*Breese, 1965, Gerber, 1989
Once daily dosing?
• Recommended by the FDA:
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azithromycin (Zithromax)
cefixime (Suprax)
cefdinir (Omnicef)
cefadroxil (Ultracef, Duracef)
ceftibutin (Cedax)
• Amoxicillin (750 mg once daily)*
*Feder, Pediatrics, 1999
Shorter courses?
• Approved by the FDA for 5-day
regimen:
– cefpodoxime (Vantin)
– cefdinir (Omnicef)
– azithromycin (Zithromax)
What about the penicillinallergic child?
• Erythromycin estolate (20-40
mg/kg/d divided bid) or
ethylsuccinate (40 mg/kg/d divided
bid)
• Azithromycin (12 mg/kg/d x 5 d),
clarithromycin (15 mg/kg/d div q 12
hrs), clindamycin (20 mg/kg/d div q
6-8 hrs)
Why penicillin might “fail”
• Non-adherance to prescribed
therapy
• failure to recognize carriers
• ? beta-lactamase production by
other pharyngeal flora
• new streptococcal infection
Case #2
A 13-year-old boy has had fever and sore
throat for two days. He now presents
with a cough. On examination he has a
temperature of 104, RR 22, O2
saturation of 98%, retractions, and
crackles over the posterior left lower
lung. Chest x-ray confirms a left lower
lobe pneumonia.
What do you think is causing his pneumonia?
How will you treat him?
Common Causes of Community-Acquired Pneumonia in
Otherwise Healthy Children
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Viruses
– Respiratory syncytial virus
– Influenza A and B
– Parainfluenza 1, 2, and 3
– Adenovirus
– Rhinoviruses
– Measles virus
Mycoplasma
– Mycoplasma pneumoniae
Chlamydia
– Chlamydia pneumoniae
– Chlamydia trachomatis
• Bacteria
– Streptococcus pneumoniae
– Mycobacterium
tuberculosis
– Staphylococcus aureus
– Haemophilus influenzae
type b
– non-typable H. influenzae
McIntosh,K: NEJM 2002;346:429
Likelihood that the pneumonia
is bacterial is greater if:
• Fever is > 39 degrees C
• The patient “looks sick”
• There are alveolar infiltrates on chest xray
• WBC is > 15,000
• NB: Blood culture is positive in about 10%
of infants and children with bacterial
pneumonia and more likely in those > 2 yrs
Bacterial pneumonia according to age:
• < 28 days: Group B streptococcus, Gram
negative enterics, CMV, listeria
• 3 wks - 3 months: C trachomatis, RSV,
parainfluenza, S. pneumoniae, B. pertussis,
Staph aureus
• 4 months-4 years: respiratory viruses, S.
pneumoniae, M. pneumoniae, H. influenzae,
TB
• 5 - 15 years: M. pneumoniae, S. pneumoniae,
C. pneumoniae, TB
Antibiotics for pneumonia-according to age:
• < 28 days: ampicillin and gentamicin
• 1 month - 3 months: macrolide (afebrile) +
cefotaxime/ceftriaxone (fever)
• 4 months - 4 years:
– NO ANTIBIOTICS FOR VIRAL INFECTION
Amoxicillin (80-100 mg/kg/d divided tid) OR
ampicillin 200 mg/kg/d divided q 6 hrs, OR
cefuroxime or cefotaxime
• 5 - 15 years: macrolide + IV ampicillin OR
cefuroxime OR cefotaxime
Beta-lactam-resistant S. pneumoniae:
• Intermediate resistance: MIC = 0.1-1
microgram/ml
• High level resistance: MIC > 2
micrograms/ml
• 100,000 units/kg of penicillin G yields a
serum concentration of about 10
micrograms/ml
• 500 mg of amoxicillin yields a serum
concentration of about 8 micrograms/ml
Importance of beta-lactamresistant S. pneumoniae:
• Highest risk in children
– < 3 years
– day care
– recent antibiotics
• Can be overcome by high doses of
penicillin/ampicillin
• Impact of Prevnar for immunized children?
– 11% fewer episodes of pneumonia, 33% fewer
with abnormal x-ray, 73% fewer with extensive
disease
What if his RR was 35, his O2
saturation was 85% and he had an
effusion on chest x-ray?
Don’t forget Staphylococcus
aureus and group A
streptococcus in children with
large effusions who look very
sick. IV clindamycin should be
added for these children.
Case #3
A two-month-old girl is brought to your
office because of a 5-day history of
rhinorrhea and cough. She has been
afebrile. On exam she has rhinorrhea
and coughs frequently. There are
scattered crackles and wheezes
throughout her lung fields.
What is the cause of her respiratory symptoms?
How will you treat her?
Antibiotics for pneumonia-according to age:
• < 28 days: ampicillin and gentamicin
• 1 month - 3 months: macrolide (afebrile) +
cefotaxime/ceftriaxone (fever)
• 4 months - 4 years:
– NO ANTIBIOTICS FOR VIRAL INFECTION
Amoxicillin (80-100 mg/kg/d divided tid) OR
ampicillin 200 mg/kg/d divided q 6 hrs, OR
cefuroxime or cefotaxime
• 5 - 15 years: macrolide + IV ampicillin OR
cefuroxime OR cefotaxime
Think about
• Pertussis
– Any contacts with cough illness?
– Is the cough paroxysmal?
– Chest x-ray--pertussis only rarely is
associated with pulmonary infiltrates
– CBC to look for lymphocytosis
• Chlamydia
– Maternal history of chlamydia?
And think about
• Viruses
– Contacts?
– Season? (RSV, influenza, parainfluenza,
enteroviruses)
• Antibiotic?
– The only class that makes sense is
macrolides--erythromycin estolate,
clarithromycin, azithromycin
Case #4
A four-year-old girl has had rhinorrhea,
cough, and intermittant fever for 12
days. Her mom thinks there has been
no improvement in her symptoms
during that time. On exam she has a
temperature of 100.5, rhinorrhea,
and cough.
What is your diagnosis?
AAP Clinical Practice Guideline
(September, 2001)
• Diagnose acute sinusitis based upon
persistent symptoms, no need for
radiologic studies
• Treat with antibiotics as per acute
otitis media recommendations
• BUT. . . .
Findings from Garbutt,JM, et al: Pediatrics:
2001;107:619 in a study of 161 patients
1-18 years old (50% < 7 yrs) with symptoms
between 10-28 days
Criticism of Garbutt study:
• Children included were only mildly ill
• Diagnosis wasn’t confirmed by x-ray
• Inclusion of older children whose
disease was likely mild
• Symptomatic therapy was permitted
• Antibiotic doses prescribed may
have been inadequate
Wald (letter):Pediatr 2002;109:166
Case # 5
A 6-year old girl developed varicella 7 days ago. She
had fever for the first 4 days of her illness.
Fever resolved but returned 1 day ago. Now she
complains of pain in her left leg. On exam she has
a temp of 102.5, scabbed varicella lesions over her
trunk, face, and extremities, and tenderness over
her left ankle region. There is also redness and
tenderness around one of the scabbed lesions on
her abdomen.
What is your major concern?
Cases of varicella at a childcare center, by
date of onset--Boston, MA January-Februar
1997
Cases of group A streptococcus at a
childcare center by date of onset-Boston, MA, January-February, 1997
MMWR;1997:46:944
Bacterial complications
associated with varicella:
Treat for group A streptococcal
infection, but keep
Staphylococcus aureus in mind.
Case # 6
An 18-month-old girl presents with continuing
symptoms after 4 days of treatment with
amoxicillin for acute otitis media. She is
still complaining of ear pain, she has a
temperature of 38.8 degrees C., and she is
irritable. On exam you find that her TM is
white and bulging with decreased mobility.
What is/are the likely cause(s) of her
persistent findings?
How will you treat her?
Appropriate questions:
• What dose of amoxicillin was
prescribed?
• Did she take it?
• What is the likelihood of infection
with resistant pneumococcus?
• What other bacteria do you want to
treat?
• Risk that this infection is due to S.
pneumoniae:
– Acute otitis media due to S. pneumoniae
is least likely to resolve spontaneously
• Risk factors for infection with
resistant S. pneumoniae:
– < 3 years
– day care attendance
Treatment options:
• Continue current therapy (there is no
direct relationship between the
persistence of symptoms and the viability
of infecting bacteria)
• Increase amoxicillin to 80-90 mg/kg/day
(increase activity against resistant S.
pneumoniae)
• Increase activity against beta-lactamaseproducing organisms (H. influenzae and M.
catarrhalis)
Enhanced treatment against
beta-lactamase-producers:
• Add clavulanate (could also enhance
activity against resistant S.
pneumoniae by increasing amoxicillin
component)
• Alternate choices: cefdinir
(Omnicef), cefuroxime axetil (Ceftin),
IM ceftriaxone (Rocephin),
azithromycin (Zithromax)
Other approaches:
• Enhance compliance: reduced daily
dosing, better taste, parenteral
(ceftriaxone) therapy
• Tympanocentesis and culture
Case # 7
A 2-month old boy (born at term) is
brought to the ED because of fever,
irritability, and poor feeding for the
past 24 hours. On exam the infant
has a temp of 101, RR 50, O2
saturation 95%. He is moderately
irritable, but his exam is otherwise
normal.
How will you evaluate and treat him?
After blood, urine, and CSF
cultures have been obtained. . .
• Treatment should be aimed at which
bacterial organisms?
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S. pneumoniae
Group B streptococcus
H. influenzae
E. coli and other enterics, incl salmonella
Listeria
What’s wrong with ampicillin
and gentamicin?
Nothing, as long as the CSF
doesn’t reveal pleocytosis.
If it does, use ampicillin and
ceftriaxone/cefotaxime (and
consider vancomycin pending
cultures)
Case # 8
A 15-year-old boy was wrestling with
his neighbor’s dog and was bitten on
the arm. On exam he has a 2 cm
jagged laceration on his right
forearm.
What are the bacterial agents to
consider?
What antibiotic(s) will you use?
• Bacteria:
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Staphylococcus aureus (amp plus clav)
Pasturella multocida (penicillin/ampicillin)
Eikenella corrodens (ampicillin)
Streptococcus and Staphylococcus
species
• Don’t forget to wash the wound and
give tetanus prophylaxis if indicated
A 14-year-old girl is brought to the
pediatric ED after 18 hours of fever.
She had complained of sore throat and
headache, and went to bed early the
night before. This morning her mother
found her in the bathroom somewhat
disoriented. She had vomited once and
had an episode of diarrhea the night
before. On exam she had a temp of
103, RR 25, O2 sat 93, BP 100/35.
There were no focal findings on exam.
A 3-year-old boy has had a URI for
3-4 days. This morning his mother
noted a swelling in his left neck.
On exam he has a temperature of
102 and a tender, firm, slightly red
mass in the left anterior cervical
area.
A 2-year-old boy has a fever and a
36 hour history of increasing leg
pain and refusal to walk. On exam
his temp is 102, he is holding his
right leg in slight flexion and
abduction, there is reduced range
of motion of the hip, and he
refuses to bear weight.
A 12-month-old boy presents with
clear nasal discharge for 2 days,
difficulty sleeping, and tugging at
his right ear. On exam he has a
temperature of 102 degrees and a
bulging, white, opaque, immobile
right tympanic membrane. This is
his first episode of otitis media.