Ethanol, morphine and barbiturate alter the hemodynamic and cerebral response to cocaine in newborn pigs

Newborns delivered to cocaine-abusing mothers are often exposed to other concurrently consumed illicit drugs, which may alter the hemodynamic and cerebral response to cocaine. This study examined the interaction of ethanol, morphine or barbiturate with cocaine on mean arterial pressure (MAP), cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO₂) in newborn pigs. CBF, CMRO₂ and cerebral O₂ extraction (CECO₂) were measured before and 4 and 10 min after cocaine (1.5 mg/kg i.v.) was administered in piglets that were awake, or pretreated with morphine, ethanol or pentobarbital. In awake piglets, cocaine increased CMRO₂ and CEO₂ while it had no significant effect on CBF. Conversely, in morphine- and ethanol-pretreated piglets, cocaine decreased CMRO₂, decreased CBF and had not effect on CEO₂. In awake piglets, cocaine increased MAP, whereas in morphine- or ethanol-pretreated piglets, cocaine decreased MAP. In the pentobarbital group, cocaine had no effect. These data demonstrate that other drugs of abuse alter the hemodynamic and cerebral effects of cocaine in the immature animal and may contribute to the central nervous system abnormalities in 'crack babies'.