Dissociation constants of antipsychotic drugs at dopamine receptor subtypes
| Ki (nM) | |||
|---|---|---|---|
| D2 | D3 | D4 | |
| Chlorpromazine | 0.55 | 1.2 | 9.7 |
| Clozapine | 35 | 83 | 22 |
| Haloperidol | 0.53 | 2.7 | 2.3 |
| Olanzapine | 7.5 | 49 | 15 |
| Quetiapine | 105 | 340 | 2000 |
| Raclopride | 1 | 1.8 | 2400 |
| Remoxipride | 54 | 969 | 2800 |
| Risperidone | 1.3 | 6.7 | 7.5 |
| Sertindole | 0.38 | 1.6 | 10.1 |
| (−)-Sulpiride | 2.5 | 8 | 1000 |
| Thioridazine | 1.2 | 2.3 | 10 |
Values given for the D2(short) and D3 receptors are mostly taken from Malmberg et al. (1993),Seeman (1996), and Seeman and Van Tol (1995), and are from competition experiments versus [3H]raclopride binding to the receptors expressed in CHO cells. Values for olanzapine and quetiapine for the D3 receptor are from Schotte et al. (1996) in competition experiments versus [125I]iodosulpride. [3H]Raclopride and [125I]iodosulpride are radioligands that can be used under conditions that avoid experimental artifacts (see text). For the D4 receptor, data are taken fromSeeman (1996), Seeman and Van Tol (1994), and Seeman and Van Tol (1995) using competition versus [3H]spiperone. These values must be taken as estimates only, because it is unclear whether the binding of [3H]spiperone at the D4 receptor suffers from the same artifacts as does its binding to the D2 receptor (see Section II).