Use of opioids in prevention of and recovery from a stress-induced crash in blood pressure

Receptor-selective peptide ligands, including deltorphin-D, DADLE, and DAGO, are used to prevent the occurrence of stress-induced blood pressure crash in mammals, to improve the likelihood and speed of recovery of mammals having experienced a crash in blood pressure, or to decrease mortality due to stress-induced crashes in blood pressure and eliminate or lessen the severity of the effects of blood pressure crashes. The invention is particularly suited to blood pressure crashes induced by heat and commonly known as heat stroke. If it is anticipated that the mammal will be susceptible to heat stroke, for example due to environmental temperatures, heat sensitivity of the mammal, or stress being experienced by the mammal, for example through physical labor or exercise, a pharmaceutically effective amount of one or more of the opioids is administered prior to the onset of heat stroke. Alternative or supplementary thereto, a pharmaceutically effective amount of one or more of the opioids is administered to a mammal after the onset of heat stroke.