Structural formula of aripiprazole in 2D
Aripiprazole is an atypical neuroleptic.
Neuroleptics are used in the therapy of schizophrenia, because they are anti-psychotic and sedating. They can be divided into generations and can then be further devided by phamacological potency:
1st generation: - High potency neuroleptics (f.ex. Haloperidol, Fluphenazine, Perphenazine)
- low potency neuroleptics (f.ex. Promethazine, Melperone, Levomepromazine)
2nd generation: atypical neuroleptics (z.B. Olanzapine, Clozapine, Quetiapin, Risperidon)
Because psychoses are primarily the result of effects of the neurotransmitters dopamine and serotonine, their receptors in the CNS have to be inhibited for treatment.
Diffenrent active ingredients bind competitively to D2- (dopamine-) or 5HT2- (serotonin-) receptors and regulate as antagonists the influence of the neurotransmitters on the psyche.
Apiprazole is a partial-agonist at the D2- 5HT1A-receptors (anxiolytic). If the activity of the neurotransmitter dopamine is lowered, apiprazol can function as an angonist at the receptor. But if dopamine concentration is high, aripiprazole blocks the receptor and reduces the effects of dopamine.
At the 5HT2A(serotonine)-receptor it is antagonistic, like other neuroleptics.
In spite of dopamine inhibition, aripiprazole only rarely causes EPS. This might be because it inhibits the meso-limbic D2-receptors more that the striatal ones, which are responsible for motor funtion.
Because it is metabolized by the cytochrome-system, aripiprazol should not be taken with inhibitors or inducers of that system.