Description Flupentixol is an antipsychotic neuroleptic drug. It is a thioxanthene, and therefore closely related to the phenothiazines. Its primary use is as a long acting injection given two or three weekly to people with schizophrenia who have a poor compliance with medication and suffer frequent relapses of illness. It is a D1 and D2 receptor antagonist. It is not approved in the United States. Indication For use in the treatment of schizophrenia and depression Mechanism of action Flupenthixol is a thioxanthene antipsychotic. The mechanism of action of Flupenthixol is not completely understood. Flupenthixol is a powerful antagonist of both D1 and D2 dopamine receptors, and an alpha-adrenergic receptor antagonist. It's antipsychotic activity is thought to be related to blocks postsynaptic dopamine receptors in the CNS.