Oral N-acetylcysteine administration does not stabilise the process of established severe preeclampsia

Numerous disorders, including adult respiratory distress syndrome and AIDS, are associated with a deficiency of glutathione, an intracellular antioxidant. Because N-acetylcysteine is a precursor of glutathione as well as a direct radical scavenger, and because preeclampsia is associated with decreased levels of several antioxidants, a randomized, double-blind, placebo-controlled trial of orally administered N-acetylcysteine was undertaken in women with severe, early-onset preeclampsia and/or HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome. Severe preeclampsia was defined as a diastolic blood pressure of 110 mm Hg or higher with proteinuria of at least 0.3 g/L. Half of the 38 women admitted to the study received 3 effervescent tablets containing 600 mg N-acetylcysteine every 8 hours, whereas the others received placebo tablets. The median interval from treatment to delivery was 6 days in the women given N-acetylcysteine and 5 days in placebo recipients, not a significant difference. The treatment group had stable maternal plasma N-acetylcysteine levels of 20 μmol/L. Whole blood and plasma levels of glutathione and other thiols were unaffected in actively treated women except for lower plasma homocysteine levels. Gestational age at delivery did not differ significantly between the 2 groups. A majority of women in both groups underwent operative delivery because of the mother's worsening condition or fetal distress. Women in the 2 groups had comparable numbers of complications. Approximately one third of those in each group reported side effects. Rates of neonatal morbidity and mortality did not differ in the 2 groups. The investigators conclude that oral treatment with N-acetylcysteine does not improve either maternal or neonatal outcomes in cases of severe preeclampsia and/or HELLP syndrome. It remains possible, however, that earlier treatment might confer benefit.