Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phenobarbital sodium has been used in anticonvulsant concentrations (15 to 40 micrograms/mL serum) in premature newborns in attempts to prevent periventricular and intraventricular hemorrhages. Although its clinical usefulness in this regard is controversial, phenobarbital treatment has been shown to reduce periventricular and intraventricular hemorrhages after hypertensive insult in newborn beagles. In this study cerebral blood flow values in steady state and during phenylephrine-induced hypertension with and without phenobarbital pretreatment were measured in newborn beagles. At anticonvulsant dosage, phenobarbital sodium decreased mean arterial blood pressure transiently during steady state and significantly reduced total cerebral blood flow during phenylephrine-induced hypertension without reducing mean arterial blood pressure. This phenobarbital sodium effect on cerebral blood flow was not as great in the presence of acidosis, and the initial hypotensive effect of phenobarbital sodium was sustained for a longer period of time during acidosis. Phenobarbital sodium may reduce the incidence of hemorrhages in the newborn brain by providing protection against isolated hemodynamic stresses characterized by acute increases in cerebral blood flow, with or without increased mean arterial blood pressure.
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PMID:Phenobarbital and cerebral blood flow during hypertension in the newborn beagle. 221 12

Periventricular and intraventricular intracerebral hemorrhages occur frequently in premature newborns and are markers for, or contribute significantly to, neurologic morbidity in survivors. Hemorrhages are hypothesized to result from rapid fluctuations in cerebral perfusion pressure and/or cerebral blood flow. Phenobarbital sodium has been given to premature infants in anticonvulsant dosages in attempts to prevent hemorrhages, but its efficacy in clinical studies has been disputed. In this study, in the 24 to 72-hour-old newborn beagle, an animal model for periventricular and intraventricular intracerebral hemorrhage, phenobarbital sodium was administered to obtain anticonvulsant serum levels prior to phenylephrine-induced hypertensive insult. None of the animals was hypoxic or hypercarbic. Resulting hypertensive systemic mean arterial BPs were 99 +/- 8 mm Hg in the 15 control pups and 93 +/- 15 mm Hg in the 15 phenobarbital sodium-treated pups (not statistically significantly different). The duration of the hypertension was the same in both groups. Phenobarbital caused a significant decrease in mean arterial BP in the treated group just after its administration (P less than .05). Six of the 15 control pups (40%) and one of the 15 treated pups (7%) demonstrated macroscopic and microscopic periventricular and intraventricular hemorrhage (P less than .05, chi 2, Yates correction). Thus, in nonasphyxiated newborn beagles, phenobarbital sodium significantly reduced the incidence of hemorrhage after hypertensive insult.
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PMID:Reduction in incidence of periventricular, intraventricular hemorrhages in hypertensive newborn beagles pretreated with phenobarbital. 358 44

Phenobarbital sodium (PhS) has been used in anticonvulsant concentrations in premature newborns in attempts to prevent peri- and intraventricular hemorrhages (PIVH). Its effectiveness in preventing PIVH in clinical situations is still uncertain; however, PhS has reduced PIVH after hypertension in newborn beagles, and it has lowered cerebral blood flow (CBF) during hypertension in newborn beagles and piglets. We hypothesized that PhS might reduce CBF during systemic hypotension. Twelve control and 12 PhS-treated piglets (1 to 2 d old) were used for microsphere determinations of CBF during 1) steady state; 2) 30 min after PhS (treatment group) or saline infusion (controls); and 3 and 4) during two levels of graded hypotension. Mean arterial blood pressure (MABP) was 61 +/- 13 (SD) mm Hg (controls) and 57 +/- 13 (SD) mm Hg (PhS) during steady state. Thirty min after the PhS or saline infusion, MABP and CBF remained unchanged in both groups. CBF during hypotension at MABP of 41 +/- 5 (SD) mm Hg was significantly higher in controls than was CBF at MABP of 39 +/- 6 (SD) mm Hg in the PhS-treated group (p = 0.044); CBF in the two groups during the second hypotensive phase was not significantly different. However, LOWESS regression suggested that the CBF from the controls dropped as the arterial pressure decreased to less than 37 mm Hg, whereas PhS treatment lowered CBF during hemorrhagic hypotension compared with controls at blood pressures greater than 37 mm Hg but did not lower CBF further at lower systemic blood pressures.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Phenobarbital and cerebral blood flow during hypotension in newborn pigs. 837 19