1、Update on use of antibiotics in GPDr Lau Pui LamIntroduction empirical therapy and the choices of antibiotics may vary a great deal even for the same provisional diagnosis.On some occasions,inadequate dose and duration were prescribed antimicrobial guideline is an essential tool to promote rational
2、use of antimicrobial agents with better application of existing knowledge and adherence to good practice IMPACT was developed in 1999 towards better control of the growing problem of antimicrobial resistance in Hong Kong a DH working group was formed in March 2001 to work out clinical guidelines on
3、the use of antimicrobials for common infections in primary health care setting of the DHTodays Menu CAP UTI ENT GynaecologicalRespiratory tract infectionURTI Acute inflammation of nasal or pharyngeal mucosa in the absence of other specifically defined respiratory infections such as sinusitis(ICPC)co
4、ugh,sore throat,acute nasal congestion,rhinorrhea and sputum Particular attention to high-risk pt such as young children,frail elderly,immuno-compromised,and pt w/chronic illness“Doc,I want antibiotics”URTI most common etiology is viral in over 80-90%of patients includes rhinovirus,respiratory syncy
5、tial virus,influenza virus,parainfluenza virus and coronavirus.differentiating between bacterial and viral infections may not be possible on clinical grounds alone.Also might not be as helpful as some think primary goal to rule out serious illnessURTI not enough evidence of significant benefits from
6、 the treatment of URTI with antimicrobials significant increase in adverse effects (The Cochrane Library,Issue 1,2001).In view of the lack of efficacy and low complication rates,antimicrobials treatment of children with URTI is not supported by current evidence from randomised trials emphasizing pos
7、itive aspects of non-antimicrobial treatmentCommunity Acquired PneumoniaManagement in children Aetiology and Epidemiology What is most common bacterial cause of pneumonia in childhood?Is age is a good predictor of the likely pathogens?Aetiology and epidemiology Streptococcus pneumonia is the most co
8、mmon bacterial cause Age is a good predictor of the likely pathogens Viruses are most commonly found as a cause in younger children In older children,when a bacterial cause is found,it is most commonly S pneumoniae,mycoplasma and chlamydia pneumoniaA significant proportion of cases of CAP(8-40%)repr
9、esent a mixed infectionViruses alone appear to account for 14-35%of CAP in childhoodIn 20-60%of cases a pathogen is not identifiedHome vs Hospital mx:Severity AssessmentSeverity assessment Indicators for admission to hospital Oxygen saturation 70/min in infants and RR50/min in children difficulty in
10、 breathing Intermittent apnoea Not feeding well Family not able to provide appropriate observation or supervisionGeneral management Home care Information on managing pyrexia,preventing dehydration,and identifying any deterioration Reviewed by a GP if deteriorating after 48h on treatment Chest physio
11、:not beneficial.should be not performed in children with pneumonia Antipyretics and analgesics can be used to keep the child conformable and to help coughingAntibiotic management Amoxicillin is first choice for oral antibiotic therapy in children under the age of 5 years effective against the majori
12、ty of pathogens which cause CAP in this group is well tolerated,and cheap.Alternatives are Augmentin,cefaclor,erythromycin,Klacid and azithromycin Because mycoplasma pneumonia is more prevalent in older children,macrolide antibiotics may be used as first line empirical treatment in children aged 5 a
13、nd aboveAntibiotic management Macrolide antibiotics should be used if either mycoplasma or chlamydia pneumonia is suspected Amoxicillin should be used as first line treatment at any age if S pneumonia is thought to be the likely pathogen If Staphylococcus aureus is thought the likely pathogen,a macr
14、olide or combination of flucloxacillin with amoxicillin is appropriateAntibiotic management Antibiotics administered orally are safe and effective for children presenting with CAP Iv antibiotics for severe pneumonia include augmentin&cefuroxime.If clinical or microbiological data suggest that S.Pneu
15、monia is the causative organism,amoxicillin,ampicillin,or penicillin alone may be used In a patient who is receiving iv antibiotics therapy for the treatment of CAP,oral treatment should be considered if there is clear evidence of improvementManagement in adultEpidemiology The annual incidence in th
16、e community is 5-11 per 1000 adult population CAP accounts for 5-12%of all cases of adult lower RTI managed by GP in the community The incidence of CAP requiring admission to hospital varies between 1.1 and 4 per 1000 population Between 22-42%of adults with CAP are admitted to hospitalMCQ1.25/F,fit,
17、sudden onset of high fever,severe productive cough2.70/F,ADLI,smoker with COAD and a typical presentation of CAP3.80/M OAHR bed-ridden with CAP4.40/M,cough,diarrhoea&fever.Hx of traveling abroad5.20/F,cough 3/52,failed with amoxil previous visit to farm,bird contact+a.C psittacib.H influenzaec.Influ
18、enza Ad.Enterobacteriaceaee.S pneumoniaef.Pseudomonadsg.S auerush.Coag ve staphi.M pnuemoniaej.MTBk.Legionellar spAetiology Community(%)Hospital(%)S.Pneumonia3639H.Influenza10.35.2Legionellar spp0.43.6S.Aureus0.81.9G-ve enteric bacilli1.3 1.0M pneumonia1.310.8All virus13.112.8Influenza A&B8.110.7Mix
19、ed 1114.2Other 1.72None45.330.8CAP studies conducted in the UK in different settings Aetiology Out-patients 60 years old with or without co-morbidity:pneumococci,H.influenzae,Gram negative organism and Staph.aureus immunocompromised patients:pneumococci,H.influenzae.Pneumocystis carinii,MTB,klebsiel
20、lae,pseudomonads and legionellaeAetiology Pneumonia COAD:H.influenzae and Strep.pneumoniae and occasionally by Moraxella catarrhalis.Klebsiella pneumoniae tends to cause lung infection in the debilitated elderly and alcoholic patients.Aetiology Frequency of legionella,staphlococcal,C psittaci&C bune
21、tii infection in patient with CAP in both the community and hospital is low routine enquiry about such factors is likely to be misleading Only in those with severe illness where the frequency of legionella and staphylococcal infection is higher,may enquiry about foreign travel and influenza symptoms
22、 be of predictive value.Mycoplasma pneumonia:epidemics spanning three winters occur every 4 years in the UK Clinical features Can CAP be reliably differentiated from other respiratory conditions by clinical features alone?Can the aetiology of CAP be predicted from clinical features?Clinical features
23、 Can CAP be reliably differentiated from other respiratory conditions by clinical features along?A:The diagnosis of CAP on the basis of history and PE is inaccurate without a CXR.Can the aetiology of CAP be predicted from clinical features?A:The likely etiological agent causing CAP cannot be accurat
24、ely predicted from clinical features.Specific clinical features of particular respiratory pathogensStreptococcus pneumonia increasing age,comorbidity,acute onset,high fever and pleuritic chest pain Legionellar pneumonia younger patient,smokers,absence of comorbidity,diarrhea,neurological symptoms,mo
25、re severe infection,evidence of multisystem involvement(e.g.abnormal LFT,elevated serum CK)Mycoplasma penumonia younger patient,prior antibiotics,less multisystem involvementChlamydia pneumonia longer duration of symptoms before hospital admission,headache Coxiella burnetii:male sex,dry cough,high f
26、everClinical features CAP in the elderly:are risk factors and clinical features different?Elderly patient with CAP more frequently present with non-specific symptoms and have co-morbid disease with a higher mortality rate Aspiration is a risk factor for CAP in the elderly patient,particularly nursin
27、g home residents CAP in the elderly of nursing home But:There is no evidence that the distribution of causative pathogens is different to that in other elderly with CAP.They should be treated according to the general antibiotic recommendations no specific antibiotic recommendation for nursing home a
28、cquired pneumoniaHow to assess the severity of patient with CAP?Severity assessment:adverse prognostic features“Core”clinical adverse prognostic factors(CRB-65/CURB-65)Confusion(Urea:7mmol/l)Respiratory rate 30/min BP:low BP(SBP 90mmHg and/or DBP 65 yo“Additional”clinical adverse prognostic factors
29、Hypoxaemia(SaO2 92%or PaO2 8 WBC/ml unspun urine)or leukocyte esterase dipstick test Pyuria by dipstick(80-90%SN,50%SP)Bacteriuria detected by nitrite dipstick test(90%SP,30%SN).Some suggested urine culture may not be necessary in acute uncomplicated cases in young women,and diagnostic work-ups are
30、not warranted But Urine culture is necessary when urinary tract infection occurs in men and in children or when upper tract infection is suspected.Management Relapsing infection warrants more extensive urologic evaluation Relapsing infection=recurrence occurring within 2 weeks of completion of treat
31、ment by the same organism.Proteus in urine culture warrant Ix of structural abnormalities,e.g.stone.Urethritis shares many of the same symptoms as cystitis or vaginitis.Herpes viruses,Chlamydia trachomatis,Ureaplasmas,Trichomonads and N.gonorrhoeae must be sought.Bacterial count usually around 100 C
32、FU/ml Referral to SHC if STD is suspectedAntibiotic management Due to resistance to ampicillin,septrin and nalidixic acid,empirical treatment of uncomplicated UTI in female adults:Nitrofurantoin 50-100 mg qid x 1/52 Augmentin tab one tds x 1/52 Ofloxacin 200 mg bd x 3/7 Nalidixic acid may be another
33、 possible option.Nitrofurantoin should not be used in G6PD deficiency patients fluoroquinolone should not be used in children under 12 years of age pregnant women and during lactationRecurrent Cystitis in Young Women Definition:More than 3 cystitis episodes per year.Urine culture should be done.Empi
34、rical antibiotic therapy same as acute uncomplicated cystitis but for 7-10 daysWill you suggest prophylatic therapy?Recurrent Cystitis in Young Women Prophylactic treatment(National Guideline Clearing House)Three options:Acute self treatment Postcoital prophylaxis if related to sexual intercourse(us
35、ing nitrofurantoin and fluoroquinolones).Continuous daily prophylaxis for six months e.g.using nitrofurantoin 50-100 mg/d or cefalexin(Keflex)250 mg/dAcute Cystitis in Men Urine culture Antimicrobial therapy same as acute uncomplicated cystitis,minimum of 7 days.Those with pyelonephritis or recurren
36、t infections,urologic evaluation should be performed.Consensus regarding need for urologic working up for single infection in young men is lacking.Complicated UTI E.coli accounts for fewer than one third of complicated cases as compared to more than 80%of uncomplicated cases.Urine culture is a must
37、Empirical therapy usually includes fluoroquinolone x 10-14 days follow-up urine cultures should be performed deal with the complicating factorsCystitis in Children Urine culture must be done E.coli is the causative organism in 85%of cases Optimal duration of therapy is seven days refer for investiga
38、tionAsymptomatic Bacteriuria The presence of significant bacteriuria(105 organism/ml)in the absence of symptoms.Treatment is not necessary except in children pregnant women patients with renal transplants patients who are about to undergo genitourinary tract procedureAsymptomatic Bacteriuria in Preg
39、nancy Defined as a pure culture of 105 organism/ml of urine of a person without symptoms 25-30%of untreated pregnant women with asymptomatic bacteriuria will develop symptomatic UTI during the pregnancy.The sequelae of UTI in pregnancy include pyelonephritis,premature labour,PROM and increase in ris
40、k of fetal and perinatal mortality.Treatment can significantly reduce the incidence of symptomatic UTI,low birth weight and preterm deliveryAsymptomatic Bacteriuria in Pregnancy Screening:The American College of Obstetrics and Gynecologists and the American Academy of Pediatrics(AAP):urinalysis,incl
41、uding microscopic examination and infection screen,at the first prenatal visit+/-additional urine culture determined by findings obtained from the history and physical examination The Canadian Task Force:a urine culture at 12-16 weeks of pregnancy Treatment:Pregnant women with asymptomatic bacteriur
42、ia should be treated with 3-7 day course of antibiotics Treatment should be based on the results of urine culture.MCQ1.25/F,fit,dysuria&frequency 2/7,no hematuria/loin pain/fever2.25/M,fit,dysuria&frequency 2/7,no hematuria/loin pain/fever3.40/F,dysuria+frequency 2/7,3 previous episode this yr4.80/M
43、 OAHR bed-ridden with foley catheter,asymptomatic,urine showed Klebsiella 105cfu/ml5.30/F,pregnant,incidental found MSU E.coli 105cfu/ml6.70/F,DM,gross hematuria&frequency,loin pain&fever 3/71.Augmentin 375mg tds 1/522.Nitroflurantoin 100mg QID 1/523.Augmentin 375mg tds 10/74.No need antibiotics5.Au
44、gmentin 375mg tds 3/76.Refer x AED x admissionReferenceGuidelines for the Management of Community Acquired Pneumonia in Adults 2001 Guidelines Thorax 2001;56:(suppl IV)Guidelines for the Management of Community Acquired Pneumonia in Adults 2004 UpdateGuidelines for the Management of Community Acquired Pneumonia in ChildhoodBritish Thoracic Society Standards of Care Committee Thorax 2002;57:(Suppl I)Guideline on Antimicrobial Use for Primary Health Care Clinics,Department of Health HK,January 2002
