Table 1.
Human receptor affinity of dopamine receptor partial agonists (DRPAs) and potential clinical effects (modified from 4, 5).
| Receptor | Type of activity | Affinity Ki (nM) in vitro | Potential clinical effects | ||
|---|---|---|---|---|---|
| Aripiprazole | Brexpiprazole | Cariprazine | |||
| Dopamine D2 | Partial agonist | 0.34 | 0.30 | 0.49 | Antipsychotic effect, extrapyramidal syndrome (EPS), prolactin elevation, |
| Intrinsic activity | 60% | 45% | 30% | akathisia, nausea, insomnia, subjective response to treatment | |
| Dopamine D3 | Partial agonist | 0.8 | 1.1 | 0.08 | Effects on positive and negative symptoms, procognitive effect, EPS, |
| Intrinsic activity | 28% | 15% | 71% | akathisia | |
| Serotonin 5-HT1A | Partial agonist | 1.7 | 0.12 | 2.6 | Antidepressant and anxiolytic effects, procognitive effect, reduction of EPS |
| Intrinsic activity | 73% | 60% | 39% | ||
| Serotonin 5-HT2A | Antagonist | 3.4 | 0.47 | 19 | Reduction of EPS, weight gain |
| Serotonin 5-HT2B | Antagonist | 0.36 | 1.9 | 0.58 | ? (unknown) |
| Serotonin 5-HT2C | Antagonist | 15 | 34 | 134 | Weight gain |
| Serotonin 5-HT7 | Antagonist | 10.3 | 3.7 | 111 | Antidepressant and procognitive effects |
| Histamine H1 | Antagonist | 28 | 19 | 23 | Sedation and weight gain, hypnotic and anxiolytic effects |
| Adrenergic alpha1A | Antagonist | 26 | 3.8 | 155 | Vasodilatation, hypotension, sedation, antihypertensive effects, improvement of prostate hypertrophy, effect on nightmares |
| Adrenergic alpha1B | Antagonist | 35 | 0.17 | >155 | ? (unknown) |
| Adrenergic alpha2C | Antagonist | 38 | 0.59 | >155 | Antidepressant and prosexual effects |
| Muscarinic M1 | Antagonist | >1,000 | >1,000 | >1,000 | Dry mouth, blurred vision, constipation, urinary retention, tachycardia, cognitive impairments, delirium |