D1 antagonists

Olanzapine, sold under the brand name Zyprexa among others, is an atypical antipsychotic primarily used to treat schizophrenia and bipolar disorder. It is also sometimes used off-label in cancer patients for treatment of chemotherapy-induced nausea and vomiting and as an appetite stimulant. For schizophrenia, it can be used for both new-onset disease and long-term maintenance. It is taken by mouth or by injection into a muscle.

Chlorprothixene, sold under the brand name Truxal among others, is a typical antipsychotic of the thioxanthene group.

Ketanserin, sold under the brand name Sufrexal, is an antihypertensive agent which is used to treat arterial hypertension and vasospastic disorders. It is also used in scientific research as an antiserotonergic agent in the study of the serotonin system; specifically, the 5-HT2 receptor family. The drug is taken orally.

Tetrahydropalmatine (THP) is an isoquinoline alkaloid found in several different plant species, mainly in the genus Corydalis (Yan Hu Suo), but also in other plants such as Stephania rotunda. These plants have traditional uses in Chinese herbal medicine. The pharmaceutical industry has synthetically produced the more potent enantiomer Levo-tetrahydropalmatine (Levo-THP; technically l-THP, often written L-THP), which has been marketed worldwide under different brand names as an alternative to anxiolytic and sedative drugs of the benzodiazepine group and analgesics such as opiates. It is also so

SCH-23390, also known as halobenzazepine, is a synthetic compound that acts as a dopamine D1 receptor antagonist with either minimal or negligible effects on the D2 receptor.

Ecopipam (development codes SCH-39166, EBS-101, and PSYRX-101) is a dopamine antagonist which is under development for the treatment of Lesch–Nyhan syndrome, Tourette syndrome, speech disorders, and restless legs syndrome. It is taken by mouth.