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].

In the presence of Loxapine, [ 3 H]ketanserin binds to 5-HT 2 receptor in Frontal cortex of brain in human and bovine with K i value of 6.2 nM and 6.6 nM, respectively. Loxapine has the rank order of potency for the various receptors appears to be as follows: 5-HT 2 ≥D 4 >>>D 1 >D 2 in comparing competition experiments involving the human membranes [1]. Loxapine (0-20 μM, 24 h or 72 h) reduces IL-1β secretion by LPS-activated mixed glia cultures, reduces IL-2 secretion in mixed glia cultures, and decreases IL-1β and IL-2 secretion in LPS-induced microglia cultures [2].

Loxapine (5 mg/kg; i.p.; daily for 4 or 10 weeks) decreases serotonin (S 2 ) but does not elevate dopamine (D2) receptor numbers in the rat brain [3]. Animal Model: Adult male Wistar rats (150-175 g) [3] Dosage: 5 mg/kg Administration: Intraperitoneal injection, daily for 4 or 10 weeks Result: Induced a very significant reduction (more than 50%) of serotonin (S 2 ) receptor density after 4 weeks or 10 weeks of daily injection, but did not produce any significant increase in dopamine receptor density.