Antibiotic prescribing at NSMC Sue Neal / Steve Newell 16/5/03

Plan for the meetings: Enough material for 2 meetings Consider some research Look at antibiotic prescribing at NSMC For respiratory illnesses For UTI in children

What are the problems? Do antibiotics work? – EBM to support their use? – For what conditions? Huge amounts of time used Huge costs involved Prescribing legitimises consultation Help-seeking behaviour reinforced

Antibiotic Guidelines An examination of antibiotic prescribing with reference to new guidelines and minor ailments

Conditions Acute Sinusitis Sore Throat Otitis Media Cough LRTI UTI

Sources Antimicrobial Prescribing Guidance for Primary Care SMAC Clinical Evidence

Acute Sinusitis – the evidence base Antibiotics may be effective in PROVEN acute sinusitis The adult with ‘sinusitis – like symptoms’ in primary care does not need immediate antibiotics Any effects may be minimal/modest

The guidelines say Many cases are viral Reserve Rx for severe illness/persistant symptoms Penicillin V 500mg QDS 3-7 days or Erythromycin 250 QDS

Primary-care-based randomised placebo-controlled trial of antibiotic treatment in acute maxillary sinusitis. Lancet May 17;349(9063):1476 van Buchem FL, Knottnerus JA, Schrijnemaekers VJ, Peeters MF BACKGROUND: The value of antibiotics in acute rhinosinusitis is uncertain. Although maxillary sinusitis is commonly diagnosed and treated in general practice, no effectiveness studies have been done on unselected primary-care patients. We used a randomised, placebo-controlled design to test the hypothesis that there would be an improvement associated with amoxicillin treatment for acute maxillary sinusitis patients presenting to general practice. METHODS: Adult patients with suspected acute maxillary sinusitis were referred by general practitioners for radiographs of the maxillary sinus. Those with radiographic abnormalities (n = 214) were randomly assigned treatment with amoxicillin (750 mg three times daily for 7 days; n = 108) or placebo (n = 106). Clinical course was assessed after 1 week and 2 weeks, and reported relapses and complications were recorded during the following year.

FINDINGS: After 2 weeks, symptoms had improved substantially or disappeared in 83% of patients in the study group and 77% of patients taking placebo. Amoxycillin did not influence the clinical course of maxillary sinusitis nor the frequency of relapses during the 1-year follow-up. Radiographs had no prognostic value, nor were they an effect modifier. Side-effects were recorded in 28% of patients given amoxycillin and in 9% of those taking placebo (p < 0.01). The occurrence of relapses was similar in both groups (21 vs 17%) during the follow-up year. INTERPRETATION: Antibiotic treatment did not improve the clinical course of acute maxillary sinusitis presenting to general practice. For these patients, an initial radiographic examination is not necessary and initial management can be limited to symptomatic treatment. Whether antibiotics are necessary in more severe cases warrants further study.

Practice at NSMC 58 cases of acute sinusitis examined across all clinicians Symptoms Prescribing Other Rx

Findings Wide variety in prevalence indicating diagnostic variability Symptoms - 4 = no history - 12 post URTI - 22 pain - 23 tenderness - congestion / discharge / fever

Duration- 33 had a comment regarding duration - less than 1 week = weeks to 1 year

Prescribing - 100% (1 deferred, 1 nasal spray) - Amoxicillin / Ampicillin / Erythromycin - Trimethoprim & Doxycycline For - 3 days - 5 days - 7 days ( 35) - 10 days - Other regimes

Questions What syndrome are we treating? Are the treatments evidence based? Do we need to make any changes to treatments?

Other treatments Steaming Nasal sprays Analgesia 5 went onto second ABX courses, X-ray or referral

Sore throat – the evidence base Most sore throats are viral and self- limiting Strep is isolated in 30% of sore throats BUT Asymptomatic carriage can be as high as 40% Typical features only present in 15% of patients with strep throat Recent studies do not support antibiotics as preventative of non-suppurative complications which are rare anyway

The guidelines say - indications to treat Severely inflamed throat AND marked systemic upset Conformed strep infection Scarlet fever Impaired immunity PH non-suppurative complications Evidence of obstruction with ENT referral

With Penicillin V 500mg QDS for 7 –10 days Erythromycin if allergic 250 QDS Deferred script to use if no better 3 days

Otitis Media – the evidence base Approx 80% of acute OM resolves in 3 days without Rx ABX do not influence subsequent OM or deafness at 1 month May reduce no of children still in pain 2-7 days but for each 1 improved 3 will develop ABX related side effects Repeated courses may make recurrent infection more likely

UTI in children

BMJ 1996;312: (13 April) Education and debate: ABC of Urology: URINARY INCONTINENCE AND URINARY INFECTION Chris Dawson, Hugh Whitfield Urinary tract infection: Management in children Collecting urine specimens to confirm the diagnosis of urinary tract infection is [..] difficult in children. A midstream sample can be collected from older children, but in younger children a sterile bag placed over the genitalia to catch the urine may be needed. Suprapubic aspiration of the bladder is seldom required.

..1% of boys aged under 11 years develop a urine infection, but the incidence is three times as high in girls. Most such infections occur in the first 12 months of life. The greatest danger in such children is the development of upper tract infection and subsequent renal scarring. Vesicoureteric reflux accompanies urinary tract infection in children in 20-50% of cases. Although reflux may be the cause of infection, episodes of infection may lead to transient reflux. Vesicoureteric reflux alone is not sufficient to cause renal cortical scarring - infection must also be present

Treating uncomplicated infections for 3-5 days with antibiotics usually suffices. All children with a urinary infection should be Investigated: An ultrasound scan or intravenous urogram will show abnormalities of the upper tracts. A voiding cystourethrogram should be performed to look for bladder outlet obstruction or vesicoureteric reflux. Sexual abuse as a cause of urinary infection in children should not be forgotten.

Repeated infections should be treated accordingly: Prophylactic antibiotics may be needed if more than three infections occur during six months. Preventive measures [..] include adequate fluid intake and the avoidance of constipation. If vesicoureteric reflux is discovered then conservative management is appropriate initially. Higher grades of reflux are unlikely to settle spontaneously, but lower grade reflux – i.e. not reaching the renal pelvis – may settle without intervention. Surgery is likely to be needed if repeated infections occur while the child is taking prophylactic antibiotics, if antibiotic compliance is low, or if reflux persists after lengthy surveillance.

BMJ 1999;319: ( 30 October ) Clinical review: Clinical evidence Urinary tract infection in children James Larcombe, general practitioner. Sedgefield, County Durham TS21 3BN This review of the effects of treatment for urinary tract infection in children and of preventive interventions is one of over 60 chapters in the first issue of Clinical Evidence, published by the BMJ Publishing Group.

Key messages: Treating symptomatic acute urinary tract infection in children with an antibiotic is accepted clinical practice and trials would be considered unethical We found little evidence on the effects of delaying treatment while awaiting microscopy or culture results, but retrospective observational studies suggest delayed treatment may be associated with increased rates of renal scarring One systematic review of randomised controlled trials (RCTs) has found that antibiotic treatment for seven days or longer is more effective than shorter courses

We found no convincing evidence of benefit from routine diagnostic imaging of all children with a first urinary tract infection, but subgroups at increased risk of future morbidity may benefit from investigation. Because such children cannot currently be identified clinically, investigating all young children with urinary tract infection may be warranted Two small RCTs found that prophylactic antibiotics prevented recurrent urinary tract infection in children, particularly during the period of prophylaxis. The long term benefits of prophylaxis have not been adequately evaluated, even for children with vesicoureteric reflux. The optimum duration of treatment is unknown One systematic review and a subsequent multicentre RCT found no difference between surgery for vesicoureteric reflux and medical management in preventing recurrence or complications from UTI

Practice at NSMC 33 cases of Hx entry UTI over 3 years Age range 1year – 14years Symptoms including abdo pain, dysuria, frequency, vomiting, fever, wetting 15% no symptoms recorded 72% urine dip recorded, 7 did not, 2 noted not possible All those with urine dip reported positive

Prescribing for UTI NSMC Of all positive dips all but 2 had ABX immediately 2 positive dips awaited MSU before Rx Where dip not possible 2 awaited MSU before Rx 17 had Trimethoprim, 9 Amox/Amp, 1 Cipro Length of Rx ranged from 3 – 10days (Trimethoprim 10 days, Amp 5 days)

MSU 63% had MSU result 21% had MSU mentioned in Hx but not result appeared 39% MSU positive

Referral 50% positive MSUs were referred on first infection 2 negative MSUs were referred 4 were referred after subsequent infections 3 investigated in house with USS 1 not referred (seen at hospital)

Issues Hx entries, symptom recording Prescribing MSUs FU and referral – esp from hospital In house investigation? Haematuria??

Consider the issue of antibiotic prescribing in sore throat ~

Double blind RCTs suggest antibiotics give only marginal benefit when prescribed for common acute respiratory illnesses Yet antibiotics are still widely prescribed in this situation Is the problem that doctors do not feel that RCTs are applicable to the usual practice setting? What is the problem?

Paper for discussion: “Open randomised trial of prescribing strategies in managing sore throat” Little et al, BMJ 1997, 314, 722 (8 th March) The objective of this study was to assess three prescribing strategies for sore throat – antibiotics, no antibiotics or deferred prescription for antibiotics

Description of paper - 1 Objective – to assess three prescribing strategies for sore throat Open randomised follow-up study – involved discussion with patients Provides another model for clinical management

Description of paper - 2 Setting – 11 practices in South and West Region 716 patients with ST and an abnormal physical sign in the throat – 84% had “tonsillitis” or “pharyngitis” Patients randomised to three groups: antibiotics for 10/7 (246), no prescription (230), prescription to be used if symptoms were not settling after 3/7 (238) – in fact add to 714

Results - 1

Results - 2

Results % of patients in deferred group did not use the prescription Legitimisation of illness for school or work (60%) was an important reason for consultation Patients who were more satisfied with the way the doctor dealt with them got better more quickly

Conclusion in paper “Prescribing antibiotics for sore throat only marginally affects the resolution of symptoms but enhances belief in antibiotics and intention to consult in future when compared with the acceptable strategies of no prescription or delayed prescription”.

Another paper “A RCT of delayed antibiotic prescribing as a strategy for managing uncomplicated respiratory tract infection in primary care”. Dowell et al, BJGP, 2001, 464, 200 (March) Reached similar conclusions.

What this means Antibiotics are not always needed for sore throat to resolve Strategy of deferred prescription can reduce antibiotic usage Patients can be managed in this way and still remain happy with their care

Next steps Can this idea be generalised? What about acute cough? What about conjunctivitis? What about otitis media? What about sinusitis? Other conditions?