Thiothixene (trade mark Navane) belongs to a class of antipsychotics known as the first-generation antipsychotics, sometimes referred to as conventional or typical antipsychotics. Thiothixene is a thioxanthene antipsychotic which elicits antipsychotic activity by postsynaptic blockade of CNS dopamine receptors resulting in inhibition of dopamine-mediated effects; also has alpha-adrenergic blocking activity. Thiothixene is effective in the management of schizophrenia. Only cis isomer of thiothixene exerts clinical effectivity.

Pimozide (Orap) is a diphenylbutylpiperidine that is effective as an antipsychotic agent and as an alternative to haloperidol for the suppression of vocal and motor tics in patients with Tourette syndrome. It is not intended as a treatment of first choice nor is it intended for the treatment of tics that are merely annoying or cosmetically troublesome. It should be reserved for use in Tourette’s Disorder patients whose development and/or daily life function is severely compromised by the presence of motor and phonic tics. Evidence supporting approval of pimozide for use in Tourette’s Disorder was obtained in two controlled clinical investigations, which enrolled patients between the ages of 8 and 53 years. Most subjects in the two trials were 12 or older. Pimozide is an orally active antipsychotic drug product, which shares with other antipsychotics the ability to blockade dopaminergic receptors on neurons in the central nervous system. Although its exact mode of action has not been established, the ability of pimozide to suppress motor and phonic tics in Tourette’s Disorder is thought to be a function of its dopaminergic blocking activity. However, receptor blockade is often accompanied by a series of secondary alterations in central dopamine metabolism and function which may contribute to both pimozide’s therapeutic and untoward effects. In addition, pimozide, in common with other antipsychotic drugs, has various effects on other central nervous system receptor systems which are not fully characterized.

Molindone (Moban) is a therapeutic antipsychotic, used in the treatment of schizophrenia. The exact mechanism has not been established, however, based on electroencephalogram (EEG) studies, molindone is thought to act by occupying (antagonizing) dopamine (D2) receptor sites in the reticular limbic systems in the brain, thus decreasing dopamine activity. Decreased dopamine activity results in decreased physiological effects normally induced by excessive dopamine stimulation, such as those typically seen in manifestations of psychotic disorders. The side effect profile of molindone is similar to that of other typical antipsychotics. Unlike most antipsychotics, however, molindone use is associated with weight loss.

Haloperidol is a phenyl-piperidinyl-butyrophenone that is used primarily to treat schizophrenia and other psychoses. It is also used in schizoaffective disorder, delusional disorders, ballism, and Tourette syndrome (a drug of choice) and occasionally as adjunctive therapy in mental retardation and the chorea of Huntington disease. It is a potent antiemetic and is used in the treatment of intractable hiccups. Haloperidol also exerts sedative and antiemetic activity. Haloperidol principal pharmacological effects are similar to those of piperazine-derivative phenothiazines. The drug has action at all levels of the central nervous system-primarily at subcortical levels-as well as on multiple organ systems. Haloperidol has strong antiadrenergic and weaker peripheral anticholinergic activity; ganglionic blocking action is relatively slight. It also possesses slight antihistaminic and antiserotonin activity. The precise mechanism whereby the therapeutic effects of haloperidol are produced is not known, but the drug appears to depress the CNS at the subcortical level of the brain, midbrain, and brain stem reticular formation. Haloperidol seems to inhibit the ascending reticular activating system of the brain stem (possibly through the caudate nucleus), thereby interrupting the impulse between the diencephalon and the cortex. The drug may antagonize the actions of glutamic acid within the extrapyramidal system, and inhibitions of catecholamine receptors may also contribute to haloperidol's mechanism of action. Haloperidol may also inhibit the reuptake of various neurotransmitters in the midbrain, and appears to have a strong central antidopaminergic and weak central anticholinergic activity. The drug produces catalepsy and inhibits spontaneous motor activity and conditioned avoidance behaviours in animals. The exact mechanism of antiemetic action of haloperidol has also not been fully determined, but the drug has been shown to directly affect the chemoreceptor trigger zone (CTZ) through the blocking of dopamine receptors in the CTZ. Haloperidol is marketed under the trade name Haldol among others.