Journal ClubKavi Aucharaz 22.1.2014

Amoxycillin clavulanate in children with chronic wet cough

Aim

To determine the efficacy of a 2 week course of Amoxycillin Clavulanate in the treatment of children with chronic wet

cough

Case presentation• 3 year old seen in AAU with a chronic wet cough for 5

months• GP tried salbutamol and steroid inhalers no effect• No audible wheeze• Is it PBB and require prolonged course of antibiotics?• Can we achieve cough resolution by treating chronic

wet coughs with Amoxycillin clavulanate in children?

PBB-Protracted Bacterial Bronchitis

• Defined as presence of isolated chronic wet cough– Resolution of cough with appropriate abx– Absence of an alternative cause for specific cough

• Speculation that PBB maybe a precursor to chronic suppurative lung disease - left untreated

Current guidelines• Recommend abx for children with PBB• Advice based on a Cochrane review prospective and

retrospective observational studies• Cochrane review of abx treatment for moist cough in

children showed– Abx were effective– 1 clinical cure for every 3 children treated(95% CI 2 to 4)

Cochrane review

• Based on 2 small studies of children with cough >10 days—not current definition

• Current definition of chronic cough > 4 weeks• Neither study used validated outcome measures of

cough– Parental reporting of cough in children is subject to bias

Placebo controlled RCT –Unicentre parallel study in Brisbane

• Double-blind RCT • Aimed to assess efficacy of 2 weeks of oral

amoxicillin clavulanate • Compared with placebo in achieving cough resolution

in children with chronic wet cough

Inclusion criteria Excluding criteria

• Children aged 6mo-18 yrs• Newly referred to

respiratory practice• Jan.2004- Dec 2006• Chronic cough (> 3 wks)+

doctor observed moist/wet cough

• Gross neuro-devlopmental delay

• CF, Ex-prem (<37 weeks gest.)• Chr. Disease , interstitial lung

disease or cardiac abn.• Suspicion of bronchiectasis• Haemoptysis• Abx therapy received in

preceding 2 wks• Penicillin allergy/acutely unwell

with fever or pnemonia

Randomisation and allocationComputer generatedStratified by age(<6yrs and >6yrs)Parents and members of study were blinded to the child’s

allocated group

Data collectionStandardised data collection sheets were used Parents completed a daily cough diary for 28 days post

enrolment--presence and severity of cough--any adverse reactions to medications were documented

Validated cough diary using the verbal category descriptive score (VCD) was used

Cough scoring system -- has best correlation with objective counts as measured by cough meter

Verbal Category Descriptive score(validated cough diary)• 0=no cough• 1=cough for one or two short periods only• 2=cough for more than two short periods• 3=frequent coughing but does not interfere with school

and other activities• 4=frequent coughing which interferes with school and

other activities• 5=cannot perform most activities due tp severe coughing

Child presenting to RCH with chronic (>3 weeks)cough

Assess for eligibility and study explained to parents

Clinical assessment : history, Physical exam±CXR

Enrolled , randomised, diary prescription, diary cards explained

Prescription taken to pharmacy

Amoxicillin-clavulanate 22.5 mg/kg/dose twice daily(0.281ml/kg)

Placebo twice daily(0.281 ml/kg)

Day 7 review(phone)

Day 14 review(phone) Routine clinical appointment arranged if still coughing

Diaries and medication bottled received by post

Bronchoscopy • Some children had flexible bronchoscopy• Not a requirement of the protocol• Children received the trial medication after the

bronchoscopy• BAL was performed –European Respiratory Society

guidelines• Microbiological exam.• Cytology and inflammatory markers• Significant bacterial growth ≥ 105 cfu/ml of BAL

OUTCOMESPrimary outcome ‘cough resolution’Defined as improvement in baseline cough score (>75% reduction

of cough)At ’end of trial’ or cessation of coughing for minimum 3/7

within trial periodBaseline cough score -- average score in the 2 days immediately

before trial medication commencement ‘End of trial’ score - the score 2 days following completion of 14

days of medication(D15-16)Secondary outcome measure were absolute change in cough

score and change in VCD score over the study

Statistical methods• Sample size of 55-60• At 5% significance this provides a study power of 82%• With 20-30% dropout rate to detect a difference of 60%

between groups-(75% improvement in abx group,30% in placebo group)

• Without dropouts- sample size of 23 per group provided same power for the same effect size

• Dropout rate was low –study was ceased when 50 enrolled

Statistical analysis• Data were analysed with intention to treat• Children lost in F/U –considered failures• SPSS V.12• Medians and IQR were used for descriptive data• Not normally distributed data were analysed using non-

parametric analyses• Mann-Whitney U test used for comparisons b/w the 2

groups• Proportions between groups were compared using chi-

squared test• Two tailed p value <0.05 considered significant

Results• 55 patients approached, 50 enrolled• 3 children lost to FU-unable to contact• All 50 children were included in final analysis• Similar no. in both arms had bronchoscopy(19,18)• BAL data - consistent with PBB in majority children• BAL microscopy identified

Haemophilus influenza(n=14. 34%) Strep, pneumoniae(n=9, 24%) Moraxella catarrhalis(n=7, 19%) All these organisms were sensitive to Amoxycillin clavulanate

Assessed for eligibilityN=55

Randomised (n=50)

Excluded(n=5)Decline to participate(n=3)

Not meeting inclusion criteria(n=2)

Allocated to Abx(n=25)Received allocated intervention(n=25)

Allocated to placebo(n=25)Received allocated intervention(n=25)

Lost to follow up(n=2)[reasons :unable to contact(n=2)]Discontinued intervention(n=1)

Lost to follow-up(n=1)[reasons: unable to contact(n=1)]Discontinued interventions(n=0)

Analysed for cure(n=25)Secondary outcomes:• Excluded from analyses requiring

cough scores(as none available)(n=2)

• Bronchoscopy data;(n=19)

Analysed for cure(n=25)Secondary outcomes:• Excluded from analyses

requiring cough scores(as none available)(n=1)

• Bronchoscopy data(n=18)

Effect of intervention• Amoxycillin clavulanate group – more likely to achieve cough resolution (n=12, 48%)

v/s Placebo group (n=4, 16%) (p=0.015)• Observed difference between proportions is 0.32 (95%CI 0.08-0.56)• OR=4.85

P- Children (6mo-<18ys) with chronic wet coughI- 2 weeks course of Amoxycillin clavulanate in treatment of chronic wet coughC-PlaceboO- ‘Cough resolution’-defined as a<75 % reduction in validated VCD cough score

• Randomisation was computer generated

• Concealed allocation was used • Allocation list and trial medications

were dispensed by pharmacy• Parents and members of study were

blinded until data were analysed.

• 55 patients approached • 50 were enrolled and all received

treatment allocation• 3 lost to follow up—unable to be

contacted• All 50 children were included in the final

analyses for primary outcome

Is it worth continuing?? …Yes

• Parents and members of the study were blinded to allocated group until data were analysed

• Medication code were revealed in February 2011

• Similar numbers (n=25) in both study arms

• No significant difference between groups in any of parameters• Similar number in both arms had bronchoscopy

prior treatment commencement

• Primary outcome was ’cough resolution’• Defined as improvement in baseline cough score (>75%

reduction in cough score) at ‘end of trial’ or cessation of coughing for minimum period of 3/7 within the trial period

• Baseline cough score was children with chronic wet cough with a number need to treat –NNT (for benefit at 2 weeks) of 4

• Observed difference between proportions is 0.32(95% CI 0.08-0.56)• OR=4.85, NNT for benefit at 2 weeks was 4 (95% CI 2 to 27)• At 4 weeks further 2 children were cough free (n=14, 56%)

• Population are similar to Brisbane

• Study period Jan 2004-Dec 2006

• Both summer and winter period

• 10/13(77%) in treatment group grew significant bacteria on BAL

• Side effects were seen in both groups with no significant difference

Tablets 375 mg, f/c, co-amoxiclav 250/125 (amoxicillin 250 mg as trihydrate, clavulanic acid 125 mg as potassium salt), net price 21-tab pack = £4.19. Label: 9Tablets 625 mg, f/c, co-amoxiclav 500/125 (amoxicillin 500 mg as trihydrate, clavulanic acid 125 mg as potassium salt). Net price 21-tab pack = £8.00. Label: 9Suspension ‘125/31 SF’, sugar-free, co-amoxiclav 125/31 (amoxicillin 125 mg as trihydrate, clavulanic acid 31.25 mg as potassium salt)/5 mL when reconstituted with water. Net price 100 mL (raspberry- and orange-flavoured) = £2.95. Label: 9Suspension ‘250/62 SF’, sugar-free, co-amoxiclav 250/62 (amoxicillin 250 mg as trihydrate, clavulanic acid 62.5 mg as potassium salt)/5 mL when reconstituted with water. Net price 100 mL (raspberry- and orange-flavoured) = £3.00. Label: 9

• Re-attendance at GP• Substantial amount of burden-

family-Impact on QoL• The definition of chronic wet

cough is different currently in UK(4-6wks)

Limitations of study• Lack of follow up over period of months to assess long

term value of 2 week antibiotic therapy• Long delay between completion of study and data

analyses• Due to personal reasons of primary author

Summary and Conclusion• VERY WELL DESIGNED STUDY

• Amoxycillin Clavulanate is effective in achieving a reduction in symptoms and cough resolution in significant number of children with isolated chronic wet cough

Following Discussion

• No local guidelines at SCH for treatment of chronic wet cough

• It was felt that the long term effect of the 2 weeks course of oral antibiotics were not measured

• We do not know whether the chronic wet cough resolution was sustained for longer period

• Treating children having 3 weeks of wet cough with 2 weeks antibiotics is not justified.

• There is no concrete evidence to prove that untreated PBP leads to chronic suppurative lung disease

THANK YOU