Loxapine hydrochloride is a dibenzoxazepine anti-psychotic agent that exerts its effects through oral administration, functioning as an inhibitor of dopamine and an antagonist of 5-HT receptors [1] [4].

Loxapine, when present, facilitates the binding of [3 H]ketanserin to the 5-HT2 receptor in the frontal cortex of both human and bovine brains, with K_i values of 6.2 nM and 6.6 nM, respectively. The potency hierarchy of Loxapine across various receptors is indicated as 5-HT2 ≥ D4 >>> D1 > D2, based on competition experiments with human membranes [1]. Additionally, Loxapine at concentrations ranging from 0-20 μM over periods of 24 h or 72 h, notably decreases IL-1β and IL-2 secretion in mixed glia and LPS-induced microglia cultures, demonstrating its immunomodulatory effects [2].

Loxapine, administered at a dosage of 5 mg/kg via intraperitoneal injection daily for 4 or 10 weeks, significantly reduces the density of serotonin (S2) receptors by more than 50% in adult male Wistar rats (150-175 g) without causing an increase in dopamine (D2) receptor numbers in the rat brain [3].