ICD-10 Specific code F90: Hyperkinetic disorders

Atomoxetine is a highly selective and potent inhibitor of the pre-synaptic noradrenaline transporter, its presumed mechanism of action, without directly affecting the serotonin or dopamine transporters.

Clonidine has been shown to have both central and peripheral sites of action. With long-term treatment clonidine reduces the responsiveness of peripheral vessels to vasoconstrictor and vasodilator substances and to sympathetic nerve stimulation. Early in treatment, however, blood pressure reduction is associated with a central reduction of sympathetic outflow and increased vagal tone.

Guanfacine is a selective alpha_2A-adrenergic receptor agonist in that it has 15-20 times higher affinity for this receptor subtype than for the alpha_2B or alpha_2C subtypes. Guanfacine is a non-stimulant. The mode of action of guanfacine in ADHD is not fully established.

Methylphenidate HCl is a mild central nervous system (CNS) stimulant. The mode of therapeutic action in Attention Deficit Hyperactivity Disorder (ADHD) is not known. Methylphenidate is thought to block the reuptake of noradrenaline and dopamine into the presynaptic neurone and increase the release of these monoamines into the extraneuronal space.

Tiapride is an atypical neuroleptic which exhibits selectivity in in-vitro studies for D₂ and D₃ dopamine subtype receptors without any affinity for subtype receptors of the principal central neurotransmitters (including serotonin, noradrenaline and histamine).