Lyn Billington June 2006 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 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 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 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 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 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 Prescribing Guidelines Moore & Jefferson Handbook of Medical Psychiatry, 2nd ed AMH 2006 Jacobson: Psychiatric Secrets, 2nd ed