Magnesium sulfate pharmacokinetics: pregnant Capra hircus model

A comparison of standard clinical regimens for the administration of magnesium sulfate for treatment of preeclampsia was performed in the pregnant goat model. The regimen of intravenous or intramuscular load and intramuscular maintenance championed by Pritchard was found to yield higher maternal serum levels through the first 4 hours of treatment compared with intravenous load with intravenous maintenance therapy (p less than 0.05); however, neither regimen affected the concentration of magnesium ion in the cerebrospinal fluid. Urinary excretion of magnesium and passage into the amniotic fluid were also evaluated for each route of administration and neither accounted for the disparity in serum concentrations noted during the first 4 hours of magnesium therapy.