Hemodynamic measurements were obtained from 18 patients in shock before and after administration of chlorpromazine. Mean arterial pressure fell in all but one patient due to a reduction in systemic vascular resistance. Improved cardiac output occurred in nine patients, who, when compared to the others, had higher arterial and central venous pressures, higher vascular resistances, and had shown a poorer response to plasma volume expansion. These observations suggest that chlorpromazine will reduce vascular resistance in most patients in shock, but will not improve cardiac output if central aortic pressure is low or previous fluid replacement has been inadequate.
Loeb HS, Pietras RJ, Ninos N, Tobin JR, Gunnar RM. Hemodynamic Responses to Chlorpromazine in Patients in Shock. Arch Intern Med. 1969;124(3):354–358. doi:10.1001/archinte.1969.00300190094015