Neuroopthalmologic effects of intravenous magnesium sulfate

Magnesium sulfate is frequently used to prevent seizures in pregnant women with eclampsia and preeclampsia, pregnancy-induced disorders featuring high blood pressure and other dysfunctions. Visual disturbances are somewhat common in these patients and may be related to complications associated with high blood pressure. Visual dysfunction is often a sign of worsening of eclampsia. Although intravenous magnesium sulfate is effective and relatively safe, it may be responsible for some of the visual disturbances. To better determine the cause of visual problems in patients with eclampsia disorders, 13 women with such disorders were evaluated during and after magnesium sulfate therapy. Abnormal visual signs and symptoms were common, especially blurred or double vision, and these varied in the women during therapy. Many of the visual disturbances were most likely due to effects on the brain pathways that control vision, but other symptoms were attributable to effects of magnesium on the peripheral visual system. The visual problems could be discriminated from those resulting from retinal detachment, a somewhat common complication of eclampsia. All abnormalities normalized after termination of the treatment. Serious complications such as muscle weakness, respiratory depression, and arrhythmia (irregular, uncoordinated heartbeat) were not found. Obstetricians should be aware of these potential side effects of magnesium sulfate therapy and observe and treat patients with eclampsia disorders accordingly. (Consumer Summary produced by Reliance Medical Information, Inc.)