抗生素的應(yīng)用(英文PPT)

1、抗生素的應(yīng)用(英文PPT)抗生素的應(yīng)用(英文PPT)Is penicillin still the drug of choice for treatment of streptococcal pharygitis?AAP recommends oral penicillin V 2-3 times daily for 10 days, a single dose of benzathine penicillin, or amoxicillin 250 mg/kg tid for 10 daysLarger doses of penicillin once daily result in mor

2、e relapses*Breese, 1965, Gerber, 1989Is penicillin still the drug oOnce daily dosing?Recommended by the FDA:azithromycin (Zithromax)cefixime (Suprax)cefdinir (Omnicef)cefadroxil (Ultracef, Duracef)ceftibutin (Cedax)Amoxicillin (750 mg once daily)*Feder, Pediatrics, 1999Once daily dosing?Recommended

3、抗生素的應(yīng)用(英文PPT)抗生素的應(yīng)用(英文PPT)Why penicillin might “fail”Non-adherance to prescribed therapyfailure to recognize carriers? beta-lactamase production by other pharyngeal floranew streptococcal infectionWhy penicillin might “fail”NonCase #2A 13-year-old boy has had fever and sore throat for two days. He n

4、ow 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?Case #2A 13-year-old boy

5、 has hCommon Causes of Community-Acquired Pneumonia in Otherwise Healthy ChildrenVirusesRespiratory syncytial virusInfluenza A and BParainfluenza 1, 2, and 3AdenovirusRhinovirusesMeasles virusMycoplasmaMycoplasma pneumoniaeChlamydiaChlamydia pneumoniaeChlamydia trachomatisBacteriaStreptococcus pneum

6、oniaeMycobacterium tuberculosisStaphylococcus aureusHaemophilus influenzae type bnon-typable H. influenzaeMcIntosh,K: NEJM 2002;346:429Common Causes of Community-AcqLikelihood that the pneumonia is bacterial is greater if:Fever is 39 degrees CThe patient “l(fā)ooks sick”There are alveolar infiltrates on

7、 chest x-rayWBC is 15,000NB: Blood culture is positive in about 10% of infants and children with bacterial pneumonia and more likely in those 2 yrsLikelihood that the pneumonia Bacterial pneumonia according to age: 28 days: Group B streptococcus, Gram negative enterics, CMV, listeria3 wks - 3 months

8、: C trachomatis, RSV, parainfluenza, S. pneumoniae, B. pertussis, Staph aureus 4 months-4 years: respiratory viruses, S. pneumoniae, M. pneumoniae, H. influenzae, TB5 - 15 years: M. pneumoniae, S. pneumoniae, C. pneumoniae, TBBacterial pneumonia according Antibiotics for pneumonia-according to age:

9、2 micrograms/ml100,000 units/kg of penicillin G yields a serum concentration of about 10 micrograms/ml500 mg of amoxicillin yields a serum concentration of about 8 micrograms/mlBeta-lactam-resistant S. pneumImportance of beta-lactam-resistant S. pneumoniae:Highest risk in children 3 yearsday carerec

10、ent antibioticsCan be overcome by high doses of penicillin/ampicillinImpact of Prevnar for immunized children?11% fewer episodes of pneumonia, 33% fewer with abnormal x-ray, 73% fewer with extensive diseaseImportance of beta-lactam-resiWhat if his RR was 35, his O2 saturation was 85% and he had an e

11、ffusion on chest x-ray?What if his RR was 35, his O2 Dont forget Staphylococcus aureus and group A streptococcus in children with large effusions who look very sick. IV clindamycin should be added for these children.Dont forget Staphylococcus auCase #3A two-month-old girl is brought to your office b

12、ecause 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?Case #3A two-month-old girl isAntibioti

13、cs for pneumonia-according to age: 28 days: ampicillin and gentamicin1 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 ce

14、fotaxime5 - 15 years: macrolide + IV ampicillin OR cefuroxime OR cefotaximeAntibiotics for pneumonia-accThink aboutPertussisAny contacts with cough illness?Is the cough paroxysmal?Chest x-ray-pertussis only rarely is associated with pulmonary infiltratesCBC to look for lymphocytosisChlamydiaMaternal

15、 history of chlamydia?Think aboutPertussisAnd think aboutVirusesContacts?Season? (RSV, influenza, parainfluenza, enteroviruses)Antibiotic?The only class that makes sense is macrolides-erythromycin estolate, clarithromycin, azithromycinAnd think aboutVirusesCase #4A four-year-old girl has had rhinorr

16、hea, 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?Case #4A four-year-old girl haAAP Clinical Practice Guideline(September, 2001)Diagnose

17、acute sinusitis based upon persistent symptoms, no need for radiologic studiesTreat with antibiotics as per acute otitis media recommendationsBUT. . . .AAP Clinical Practice GuidelinFindings from Garbutt,JM, et al: Pediatrics:2001;107:619 in a study of 161 patients 1-18 years old (50% 7 yrs) with sy

18、mptomsbetween 10-28 daysFindings from Garbutt,JM, et aCriticism of Garbutt study:Children included were only mildly illDiagnosis wasnt confirmed by x-rayInclusion of older children whose disease was likely mildSymptomatic therapy was permittedAntibiotic doses prescribed may have been inadequateWald

19、(letter):Pediatr 2002;109:166Criticism of Garbutt study:ChiCase # 5A 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

20、 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?Case # 5A 6-year old girl deveMMWR;1997:46:944Cases of varicella at a childcare center, bydate o

21、f onset-Boston, MA January-February1997Cases of group A streptococcus at achildcare center by date of onset-Boston, MA, January-February, 1997MMWR;1997:46:944Cases of varicBacterial complications associated with varicella:Treat for group A streptococcal infection, but keep Staphylococcus aureus in m

22、ind.Bacterial complications associCase # 6An 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 wh

23、ite and bulging with decreased mobility.What is/are the likely cause(s) of her persistent findings?How will you treat her? Case # 6An 18-month-old girl pAppropriate questions:What dose of amoxicillin was prescribed?Did she take it?What is the likelihood of infection with resistant pneumococcus?What

24、other bacteria do you want to treat?Appropriate questions:What dosRisk that this infection is due to S. pneumoniae:Acute otitis media due to S. pneumoniae is least likely to resolve spontaneouslyRisk factors for infection with resistant S. pneumoniae: 3 yearsday care attendanceRisk that this infecti

25、on is duTreatment 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-lactamase-producin

26、g organisms (H. influenzae and M. catarrhalis) Treatment options:Continue curEnhanced 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 (

27、Ceftin), IM ceftriaxone (Rocephin), azithromycin (Zithromax)Enhanced treatment against betOther approaches:Enhance compliance: reduced daily dosing, better taste, parenteral (ceftriaxone) therapyTympanocentesis and cultureOther approaches:Enhance complCase # 7A 2-month old boy (born at term) is brou

28、ght 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?Case # 7A 2-month old boy (borAfter blood, urine, and

29、 CSF cultures have been obtained. . .Treatment should be aimed at which bacterial organisms?S. pneumoniaeGroup B streptococcusH. influenzaeE. coli and other enterics, incl salmonellaListeriaAfter blood, urine, and CSF cuWhats wrong with ampicillin and gentamicin?Nothing, as long as the CSF doesnt re

30、veal pleocytosis.If it does, use ampicillin and ceftriaxone/cefotaxime (and consider vancomycin pending cultures)Whats wrong with ampicillin aCase # 8A 15-year-old boy was wrestling with his neighbors dog and was bitten on the arm. On exam he has a 2 cm jagged laceration on his right forearm.What ar

31、e the bacterial agents to consider?What antibiotic(s) will you use?Case # 8A 15-year-old boy was Bacteria:Staphylococcus aureus (amp plus clav)Pasturella multocida (penicillin/ampicillin)Eikenella corrodens (ampicillin)Streptococcus and Staphylococcus speciesDont forget to wash the wound and give tetanus prophylaxis if indicatedBacteria:抗生素的應(yīng)用(英文PPT)抗生素的應(yīng)用(英文PPT)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 b