Clozapine appears as pale yellow crystalline powder. It is odorless, tasteless with a molecular weight of 326.83 and a melting point 183~184 °C. It is soluble in chloroform, ethanol but insoluble in water. It is withdrawn from market because of causing neutropenia in 1976. Later studies have shown that this product has a good efficacy in treating schizophrenia, and thus had re-entered into market in 1989, 1990, in Sweden and the United States, respectively. This product is a non-classical antipsychotic which can selectively block DA receptors of the mesolimbic system but has a small effect on the nigrostriatal DA receptors. It has a relatively weak blocking effect on D2 receptor, but a strong blocking effect on D1 receptors strong while also has some antagonist effect on D4 receptor and 5-HT2 receptor.

Thereby, it has strong anti-psychotic effects. Moreover EPS is less common and does not cause stiff reaction. Owing to the direct inhibition effect on the ascending reticular activating system of the brains, it has a potent sedative and hypnotic effects which can well applied for treating schizophrenia, hallucinations, delusions and youth-based effect. In addition to its good efficacy on treating positive symptoms like agitation, hallucinations, and paranoia, it also has a good efficacy on the negative symptoms.

Since this product has a different mechanism of action on blocking DA receptors with traditional antipsychotics, thus this drug may also be effective in treating some classic antipsychotic disease which fails be treated with traditional drugs.

It can also be used to alleviate mania and severe sleep disorders. In addition, it also has an anti-cholinergic effect. NE has sympathetic blocking effect, muscle relaxing effect and anti-histamine effect.