Posted by Ted (152.163.201.61) on December 28, 2000 at 11:09:33:
In Reply to: Relief - finally! posted by Deborah on December 28, 2000 at 08:54:49:
This is only part of this article from the address (if you want to read the full thing):
http://www.medscape.com/SMA/SMJ/1999/v92.n11/smj9211.01.swai/smj9211.01.swai-01.html
From
Southern Medical Journal
Magnesium for the Next Millennium
Randall Swain, MD, Barbara Kaplan-Machlis, PharmD, New Millennium Wellness and Sports Medicine, and the Departments of Family Medicine and Clinical Pharmacy, West Virginia University, Charleston.
--------------------------------------------------------------------------------
Abstract
Background. Magnesium is a trace mineral in several hundred chemical reactions in the body. It has therapeutic potential in many medical conditions. In this review, we attempted to clarify the current information on the role of magnesium as a therapeutic agent.
Methods. A MEDLINE search from 1966 through March 1999 was conducted, using PubMed and "Magnesium" and "Therapeutic Usage" as the two initial key headings. Important articles were also identified from the bibliographies of the initial articles.
Results. A total of 51 articles were included in this review. Articles were excluded if they were based on animal study or were in a language other than English.
Conclusion. Magnesium has long been used as an ingredient in laxatives and antacids. It seems clear that intravenous magnesium also is effective for the suppression of ventricular ectopy in the hospital setting and is a first-line agent for torsades de pointes. It is less clear whether it is useful in patients with congestive heart failure or acute myocardial infarction (MI). Although effective for treatment of preeclampsia/eclampsia, its use in the termination of preterm labor has recently been questioned. In asthma and chronic lung disease, intravenous magnesium may be useful when conventional treatment has failed. Finally, magnesium may have a role in the prevention and treatment of vascular headaches. [South Med J South Med J 92(11), 1999. © 1999 Southern Medical Association]
--------------------------------------------------------------------------------
Introduction
Magnesium is a trace mineral involved in more than 300 chemical reactions in the body. Similar to potassium, magnesium is predominantly an intracellular ion. More than two thirds of the total amount of magnesium is stored in bone, and about 25% is present in muscle. About one third of the total amount ingested in the gut can be absorbed, and the remaining two thirds is excreted in the feces. Magnesium absorption is proportional to the total magnesium status, ie, the higher the body stores, the lower the amount absorbed. Magnesium is similar to calcium in that it is dependent on vitamin D for absorption in the small intestine. Magnesium also acts competitively for calcium channels; therefore, it simulates a calcium channel blocker's mechanism of action. Magnesium is required for proper functioning of the Na+-K+ ATPase pump; thus, when potassium levels do not increase with supplementation, magnesium deficiency should be suspected.
(SNIPPED)
Magnesium for the Next Millenium continued...
[South Med J South Med J 92(11), 1999. © 1999 Southern Medical Association]
--------------------------------------------------------------------------------
Headaches
Magnesium is also gaining some attention for the treatment of vascular headaches. Changes in the ionized magnesium blood levels and an increase in the ionized calcium to ionized magnesium ratio have been postulated to be markers for certain patients with vascular headache.[45] Forty-two percent of migraine sufferers had low serum ionized magnesium and high ionized calcium to ionized magnesium ratios, whereas only 23% of patients with continuous daily headache had these findings. This observation was also confirmed by Mauskop et al,[46] who divided patients who had chronic daily headache into those with daily migraine headaches (DMH) and those with daily tension headaches (DTH) and found that 31% of DMH patients had low serum ionized magnesium levels and 62% had higher ionized calcium to ionized magnesium ratios. In the DTH group, only 4% had low serum ionized magnesium levels, and 37% had high ionized calcium to magnesium ratios. Abnormal visual evoked potentials, thought to be a marker for vascular headaches, have become normalized after oral magnesium supplementation.[47]
Oral magnesium has been used in two small trials for migraine prophylaxis. Both trials had small sample sizes and resulted in different conclusions. In the first trial, 135 patients received a small dose of 10 mmol of magnesium per day or 250 mg, resulting in no beneficial effects.[48] In the second trial, 43 patients received 600 mg/day, resulting in a 41.6% reduction in frequency (15.8% placebo response), and significant reductions in days with headache and less medicine use.[49] There was a nonsignificant trend in severity reduction. Both of these trials used smaller magnesium doses; routine supplementation or deficiencies often involve at least 800 mg per day (400 mg of magnesium oxide orally twice daily). Two trials have investigated acute use of 1 g of IV magnesium sulfate in the ER and have found benefits in small numbers of patients with vascular headaches or cluster headaches. Patients with low serum ionized magnesium levels responded best.[50,51]
The study of magnesium therapy for migraine is in the early stages, and we do not yet know whether it works and when to use it. Therefore, its use in this condition should probably be considered experimental for now since other, more specific effective agents are available. However, it is safe and without significant side effects and may be tried for prophylaxis if desired. The oral dosage would be 400 mg of magnesium oxide twice daily. The most common side effect is loose stool.
Summary
Magnesium is an interesting trace mineral that appears to be useful as a therapeutic agent in a number of conditions. We do not believe there is enough evidence to recommend it in the routine care of cardiac patients with acute MI or CHF. Its mainstream indications have included suppression of ventricular ectopy in a hospital setting, treatment of torsades de pointes, prevention of eclampsia, and arrest of premature labor, as well as its use as a laxative and antacid. The use of MgSO4 infusions in the hospital for treatment of asthma and COPD refractory to standard treatment is promising. The use of oral and intravenous magnesium in treating vascular headaches is experimental, but it may be tried in refractory cases since relatively few side effects appear to occur.