Is Serum Magnesium Estimate Necessary in Patients with Eclampsia on Magnesium Sulphate?

B A Ekele, S LH Badung


The therapeutic index of magnesium is said to be low, hence, there are fears of toxicity when used as anticonvulsant in eclamptic
patients. The objective of this study was to determine the serum levels of magnesium in eclamptic patients treated with
magnesium sulphate and relate the levels with clinical indicators. It was a prospective study involving consecutive eclamptic
patients that were managed between January and December 2002, with magnesium sulphate as the sole anticonvulsant agent,
using a modified Pritchard regimen. Blood samples were taken before the administration of the loading and maintenance doses of
magnesium sulphate and serum levels of magnesium were estimated using the Jenway 605 colorimeter. There were 19 patients
and 72 blood samples. The mean baseline serum magnesium was 0.72 ± 0.10mmol/L while serum magnesium levels when the
patients were on treatment ranged from 1.95 to 2.82mmol/L. No serum magnesium level was greater than 3.0mmol/L and none of
the patients had clinical evidence of magnesium toxicity. We conclude that serum magnesium levels in these patients were within
the therapeutic range, therefore, routine estimation of this cation is not necessary. Even where the laboratory facility is available,
it is suggested that serum estimation be limited to cases where clinical monitors suggest toxicity. (Afr J Reprod Health 2005;
9[1]: 128-132)

Keywords: Eclampsia, serum, magnesium, toxicity, anticonvulsant

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Harrison KA. Maternal mortality in Nigeria: the real issues. Afr J Reprod Health 1997; 1(1): 7-13.

Anthony J, Johnson RB and Duley C. Role of magnesium sulphate in seizure prevention in patients with eclampsia. Drug Safety

; 153: 188-199.

Audu LR and Ekele BA. A ten-year review of maternal mortality in Sokoto, Northern Nigeria. W Afr J Med 2002; (1): 74-76.

Hutton JD, James DK, Stirrat GM, Douglas KA and Redman CWG. Management of severe pre-eclampsia and eclampsia by UK

consultants. Br J Obstet Gynaecol 1992; 99: 554-556.

Eclampsia Trial Collaborative Group. Which anticonvulsant for women with eclampsia? Evidence from the collaborative

eclampsia trial. Lancet1995; 345: 1455-63.

Neilson JP. Magnesium sulphate: the drug of choice in eclampsia. Br Med J 1995; 311: 702-703.

Adewole IF, Oladokun A, Okewole AI, Omigbodun AO, Afolabi A, Ekele BA, et al. Magnesium sulphate for treatment of

eclampsia: the Nigerian experience. Afr J Med Sci 2000; 29: 239-241.

Magpie Trial Collaborative Group. Do women with pre-eclampsia and their babies benefit from magnesium sulphate? The

Magpie Trial: a randomized placebo-controlled trial. Lancet 2002; 359: 1877-90.

Pritchard JA, Cunningham FG and Pritchard SA. The Parkland Memorial Hospital protocol for treatment of eclampsia:

evaluation of 245 cases. Am J Obstet Gynecol 1984; 148: 951-963.

Zuspan FP. Problems encountered in the treatment of pregnancy-induced hypertension. A point of view. Am J Obstet Gynecol

; 131: 591-597.

Bergstroms S. Pre-eclampsia and eclampsia. In: Lawson JB, Harrison KA and Bergstrom S (Eds). Maternity Care in Developing

Countries. London: RCOG Press 2002, 146-156.

Sanders R, Konijnenberg A, Huijgen HJ, Wolf H, Boerk and Sanders GT. Intracellular and extracellular ionized and total

magnesium in pre-eclampsia and uncomplicated pregnancy. Clin Chem Lab Med 1999; 37(1): 55-59.

Sanders GT, Huijgen HJ and Sanders R. Magnesium in disease: a review with special emphasis on the serum ionized magnesium.

Clin Chem Lab Med 1999; 37(11/12): 1011-1033.

Lu JF and Nightingale CH. Magnesium sulphate in eclampsia and pre-eclampsia: pharmacokinetic principles. Clinical

Pharmacokinetics 2000; 38 (4): 305-314.

Chinayon P. Clinical management and outcome of eclampsia at Rajavithi Hospital. J Med Assoc Thail 1998; 81(8): 579-585.

Sawhney H, Aggarwal N, Biswas R, Vasishta K and Gopalan S. Maternal mortality associated with eclampsia and severe pre-

eclampsia of pregnancy. J Obstet Gynaecol Res 2000; 26(5): 351-356.

Ekele B A and Ahmed Y. Magnesium Sulfate regimens for eclampsia. Int J Gynecol Obstet 2004; 87:149-150.


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