haloperidol + promethazine + chlorpromazine

This is a combination of three drugs—haloperidol, promethazine, and chlorpromazine—used primarily for the rapid tranquilization of acutely agitated or aggressive patients in psychiatric emergency settings. - **Haloperidol** is a first-generation (typical) antipsychotic that acts as a potent dopamine D2 receptor antagonist, reducing psychotic symptoms such as hallucinations and agitation. - **Promethazine** is an antihistamine (H1 receptor antagonist) with strong sedative and anticholinergic properties; it helps counteract extrapyramidal side effects caused by haloperidol and adds sedation. - **Chlorpromazine** is another first-generation antipsychotic with low potency but broad receptor antagonism (dopaminergic, histaminergic, cholinergic), contributing additional sedation and antipsychotic effects. The triple combination (sometimes referred to as "HPC") has been used in Lebanon and Brazil for acute behavioral emergencies when rapid control of agitation or aggression is needed[1][3][4]. The rationale for combining these agents includes maximizing sedative/antipsychotic efficacy while minimizing certain adverse effects like acute dystonia[1][3]. However, evidence suggests that adding chlorpromazine to the more widely studied haloperidol plus promethazine regimen does not provide clear additional benefit but may increase risk of adverse effects[3].

Other names

HPC