HRB Centre for Primary Care Research Department of General Practice RCSI Medical School

HRB Centre for Primary Care ResearchDepartment of General PracticeRCSI Medical School

Trends in psychostimulant prescribing in Irish children

Udo Reulbach, Nicola Motterlini, Claire Keogh, Kathleen Bennett and Tom Fahey

Overview

• HRB Centre for Primary Care Research• Prescribing of medication in children• Ongoing research with respect to psychotropic

medications• Prevalence, core symptoms and diagnostic criteria

of Attention deficit hyperactivity disorder (ADHD)• Clinical evidence for treatment• Trends in psychostimulant prescribing

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HRB Centre for Primary Care Research

• Prescribing of medication is one of the most common interventions that patients will experience.

• The quality and standard of drug prescribing and the potential for medication error in patients is a relevant public health concern.

• The HRB Centre for Primary Care Research is interested in vulnerable groups particularly older people, pregnant women, children and drug users (Workpackage 1).

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Prescribing of medication in children

• Antibiotics are the most commonly prescribed drugs in children, representing one third of all prescriptions in this population.

• High rates of antibiotic prescribing are an increasing worldwide concern, in terms of increased antimicrobial resistance and associated burden to health services.

• Another trend is an increase in the prescription of psycholeptics and psychoanaleptics in Children.

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Psychotropic medications

• Most of the psychotropic medications are prescribed on an off-label basis. However, there is still a lack of paediatric population-based pharmacoepidemiological research.

• Study Design: A retrospective study (2002-2008) in a national Irish population aged ≤ 15 years using the Irish Primary Care Reimbursement Service (HSE-PCRS) pharmacy claims database .

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Ongoing research

Analyses of off-label prescription and time trends in prescribing of

• Benzodiazepine related drugs • Benzodiazepine derivates• Antipsychotic medication • Antiepileptic drugs• Antidepressant medication• Psychostimulant drugs

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Attention deficit hyperactivity disorder

• Prevalence estimates of attention deficit hyperactivity disorder (ADHD) vary according to the diagnostic criteria used and the population sample:

• Among school children in US: 3-5%• No objective tests exist to confirm the diagnosis of

ADHD (remains a clinical diagnosis)• Formal diagnostic criteria are most applicable to

boys aged 6-12 yearsKeen and Hadjikoumi, BMJ Clinical Evidence 2008;10:312

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Core symptoms and diagnostic criteria of ADHD

• Inattention, hyperactivity and impulsiveness• Other conditions frequently coexist with ADHD,

including developmental disorders and psychiatric disorders (particularly oppositional defiant and conduct disorder, anxiety and depressive symptoms)

• Symptoms must be present for at least 6 months, are generally observed in children before the age of 7 years and cause clinically important impairmentKeen and Hadjikoumi, BMJ Clinical Evidence 2008;10:312

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Clinical evidence

• Methylphenidate improves core symptoms.• Dexamfetamine and atomoxetine may be also

beneficial. Atomoxetine may cause rare but serious liver injury.

• Clonidine and modafinil may improve symptoms, but are associated with an increased risk of adverse effects

• Effectiveness of buproprion is unknown• Long-term effectiveness of all psychostimulants is

unknown. Keen and Hadjikoumi, BMJ Clinical Evidence 2008;10:312

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Prevalence of psychostimulant prescriptions in Ireland (2002-2008)

Age: 0-4 years Age: 5-11 years Age: 12-15 years

Patient-based rate Rate(95% CI)

Rate(95% CI)

Rate(95% CI)

MethylphendiateATC N06BA04

0.342(0.297-0.394)

8.110(7.914-8.309)

9.209(8.927-9.497)

DexamfetamineATC N06BA02

0.031(0.018-0.049)

0.197(0.168-0.230)

0.086(0.061-0.119)

ModafinilATC N06BA07

0.002(0.00004-0.010)

0.004(0.001-0.011)

0.023(0.011-0.0419)

AtomoxetineATC N06BA09

0.003(0.0004-0.013)

0.488(0.441-0.538)

0.613(0.541-0.690)

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Time trend of psychostimulant prescriptions in Ireland (2002-2008)

0

2

4

6

8

10

12

14

2002 2003 2004 2005 2006 2007 2008

Year

patie

nts/

GMS

base

d on

100

0 pa

tient

s

Male

Female

Time trend of psychostimulant prescriptions in Ireland (2002-2008)

0

20

40

60

80

100

120

2002 2003 2004 2005 2006 2007 2008

Year

pres

crip

tions

/GM

S ba

sed

on 1

000

patie

nts

Male

Female

Time trend of psychostimulant prescriptions in Ireland (2002-2008)

0

1

2

3

4

5

6

7

8

9

10

2002 2003 2004 2005 2006 2007 2008

Year

pres

crip

tions

\pati

ents

Male

Female

Non-psychostimulant prescriptions for ADHD in Ireland (2002-2008)

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Summary

• Methylphenidate is the main substance prescribed for ADHD children in Ireland

• The prevalence of psychostimulant prescriptions is increasing

• Further research required with respect to – Male-dominated prescription patterns– Co-medications– Practive variations

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U.R., N.M. and C.K. are supported by the Health Research Board of Ireland

through the HRB Centre for Primary Care Research under Grant HRC/2007/1