Transcript Psychopharmacology in Children and Adolescents

Treatment of Attention
Deficit/Hyperactivity
Disorder
Lyn Billington
Deputy Pharmacy Manager
Latrobe Regional Hospital
Lyn Billington June 2006
ADHD
• Symptoms are
• Persistent inattention-becomes a
problem at school
• Hyperactivity - often the most
prominent feature
• Impulsivity
• Accurate diagnosis essential
before commencing treatment
Lyn Billington June 2006
Course of the condition
• In most cases - spontaneous
remission
• Late adolescence about 50% still
show the full syndrome
• This falls to about 1/3 by early 20’s
• Late 20’s 10% still fully affected.
Lyn Billington June 2006
Complications
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Academic failure
Truancy
Misconduct
In adult years - more likely to have
antisocial personality disorder &
substance misuse
Lyn Billington June 2006
Etiology
• Some studies show genetic causes
• Most appear idiopathic
• Small number may be related to lead
encephalopathy or rare, inherited
resistance to thyroid hormones
Lyn Billington June 2006
Differential diagnosis
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Chaotic upbringing
Foetal alcohol syndrome
Mental retardation
Autism
Children with mania
Children with agitated depression
(
however have other symptoms not typical of
ADHD)
• Children with schizophrenia ( Have other
symptoms which rules out ADHD)
• Difficult to diagnose in adults
Lyn Billington June 2006
Treatment
• Medication is not the only treatment.
• Parent education & school support
are of major importance
• Psychostimulants can reduce
symptoms
Lyn Billington June 2006
Rationale for drug use
• Symptom relief
• To reduce function impairment in
daily life (home, school, peer)
• Minimise long term adverse effects
on academic performance
• Minimise impact on social and
emotional development
Lyn Billington June 2006
Medication used
• Short acting psychostimulants
– Dexamphetamine
– Methylphenidate
Up to 90 % will respond ( to one or the
other)
Effect is often immediate improvement in
impulsive behaviour and task completion
Lyn Billington June 2006
Mode of action and
Childrens doses
• Thought to enhance dopaminergic and
noradrenergic transmission
• Dose - dexamphetamine2.5-10mg daily
increasing by 2.5-5mg/day each week to a
maximum of 30mg per day
• Dose - methylphenidate 5-10mg/day in two
doses increasing by 5-10mg/day each week
to a maximum of 40mg /day
Lyn Billington June 2006
Short acting stimulants
– Rapid absorption – peak response 1-3
hours
– Dose titrated according to response
– Need to be given more than once daily.
– Should not be given after early
afternoon to minimise sleep disturbance
Lyn Billington June 2006
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Methylphenidate also available as
Ritalin LA ®20mg,30mg & 40mg
Concerta®18mg, 36mg & 54mg
Use conventional tables first to
establish dose then swap to the long
acting formulation
• Advantage - once daily dose
Lyn Billington June 2006
Adverse effects
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Headache
Abdominal discomfort
Appetite suppression
Insomnia
Minor effect on growth – but need to
monitor weight and height
Lyn Billington June 2006
Atomoxetine (Strattera ®)
• May be a useful alternative for
children who do not respond to
stimulants
• Indicated for children > 6 years old
• May be useful where diversion of
medication is a problem
• Monitor liver function
Lyn Billington June 2006
Mode of action and dose
• Selectively inhibits presynaptic
noradrenaline reuptake in the CNS
• Dose: < 70 kg Initially 0.5mg/kg/day
for 3 days, increasing to
1.2mg/kg/day
Lyn Billington June 2006
Adverse effects
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Nausea
Vomiting
abdominal pain
decreased appetite
irritability
temper tantrums
Rare- suicidal thoughts and behaviors
- monitor
Lyn Billington June 2006
Other therapies
• Tricyclic antidepressants – not approved
for ADHD in Australia.
• If used start low - go slow
• ECG before commencement
(cardiotoxicity)
• Consider Imipramine or Nortriptylline
Lyn Billington June 2006
• Clonidine
• No reliable evidence of effectiveness
in ADHD
• May be useful in children with ADHD
who are aggressive and where sleep
disturbance is a problem
Lyn Billington June 2006
Disadvantages of
clonidine
• Several weeks for clinical effect
• Does not seem to affect inattention
symptoms
• Risk of causing depression
• Monitor BP and pulse during therapy
• Avoid sudden cessation
Lyn Billington June 2006
Note
• Pharmacological treatment for
children and adolescents difficult
because of the lack of clinical trials
in this age group.
• Most information extrapolated from
adult trials
• Care is needed.
Lyn Billington June 2006
References
• Therapeutic Guidelines Psychotropic 2003
• The Maudsley 2005-2006 Prescribing
Guidelines
• Moore & Jefferson Handbook of
Medical Psychiatry, 2nd ed
• AMH 2006
• Jacobson: Psychiatric Secrets, 2nd
Lyn Billington June 2006
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