Magnesium Oxide in Constipation

Magnesium oxide has been widely used as a laxative for many years in East Asia, yet its prescription has largely been based on empirical knowledge. In recent years, several new laxatives have been developed, which has led to a resurgence in interest and increased scientific evidence surrounding the use of magnesium oxide, which is convenient to administer, of low cost, and safe. Despite these advantages, emerging clinical evidence indicates that the use of magnesium oxide should take account of the most appropriate dose, the serum concentration, drug-drug interactions, and the potential for side effects, especially in the elderly and in patients with renal impairment. The aim of this review is to evaluate the evidence base for the clinical use of magnesium oxide for treating constipation and provide a pragmatic guide to its advantages and disadvantages.

Nutritional interventions for treating foot ulcers in people with diabetes

BACKGROUND

Foot ulcers in people with diabetes are non-healing, or poorly healing, partial, or full-thickness wounds below the ankle. These ulcers are common, expensive to manage and cause significant morbidity and mortality. The presence of a wound has an impact on nutritional status because of the metabolic cost of repairing tissue damage, in addition to the nutrient losses via wound fluid. Nutritional interventions may improve wound healing of foot ulcers in people with diabetes.

OBJECTIVES

To evaluate the effects of nutritional interventions on the healing of foot ulcers in people with diabetes.

SEARCH METHODS

In March 2020 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that evaluated the effect of nutritional interventions on the healing of foot ulcers in people with diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors, working independently, assessed included RCTs for their risk of bias and rated the certainty of evidence using GRADE methodology, using pre-determined inclusion and quality criteria.

MAIN RESULTS

We identified nine RCTs (629 participants). Studies explored oral nutritional interventions as follows: a protein (20 g protein per 200 mL bottle), 1 kcal/mL ready-to-drink, nutritional supplement with added vitamins, minerals and trace elements; arginine, glutamine and β-hydroxy-β-methylbutyrate supplement; 220 mg zinc sulphate supplements; 250 mg magnesium oxide supplements; 1000 mg/day omega-3 fatty acid from flaxseed oil; 150,000 IU of vitamin D, versus 300,000 IU of vitamin D; 250 mg magnesium oxide plus 400 IU vitamin E and 50,000 IU vitamin D supplements. The comparator in eight studies was placebo, and in one study a different dose of vitamin D. Eight studies reported the primary outcome measure of ulcer healing; only two studies reported a measure of complete healing. Six further studies reported measures of change in ulcer dimension, these studies reported only individual parameters of ulcer dimensions (i.e. length, width and depth) and not change in ulcer volume. All of the evidence identified was very low certainty. We downgraded it for risks of bias, indirectness and imprecision. It is uncertain whether oral nutritional supplement with 20 g protein per 200 mL bottle, 1 kcal/mL, nutritional supplement with added vitamins, minerals and trace elements, increases the proportion of ulcers healed at six months more than placebo (risk ratio (RR) 0.80, 95% confidence interval (CI) 0.42 to 1.53). It is also uncertain whether arginine, glutamine and β-hydroxy-β-methylbutyrate supplement increases the proportion of ulcers healed at 16 weeks compared with placebo (RR 1.09, 95% CI 0.85 to 1.40). It is uncertain whether the following interventions change parameters of ulcer dimensions over time when compared with placebo; 220 mg zinc sulphate supplement containing 50 mg elemental zinc, 250 mg magnesium oxide supplement, 1000 mg/day omega-3 fatty acid from flaxseed oil supplement, magnesium and vitamin E co-supplementation and vitamin D supplementation. It is also uncertain whether 150,000 IU of vitamin D, impacts ulcer dimensions when compared with 300,000 IU of vitamin D. Two studies explored some of the secondary outcomes of interest for this review. It is uncertain whether oral nutritional supplement with 20 g protein per 200 mL bottle, 1 kcal/mL, nutritional supplement with added vitamins, minerals and trace elements, reduces the number of deaths (RR 0.96, 95% CI 0.06 to 14.60) or amputations (RR 4.82, 95% CI 0.24 to 95.88) more than placebo. It is uncertain whether arginine, glutamine and β-hydroxy-β-methylbutyrate supplement increases health-related quality of life at 16 weeks more than placebo (MD -0.03, 95% CI -0.09 to 0.03). It is also uncertain whether arginine, glutamine and β-hydroxy-β-methylbutyrate supplement reduces the numbers of new ulcers (RR 1.04, 95% CI 0.71 to 1.51), or amputations (RR 0.66, 95% CI 0.16 to 2.69) more than placebo. None of the included studies reported the secondary outcomes cost of intervention, acceptability of the intervention (or satisfaction) with respect to patient comfort, length of patient hospital stay, surgical interventions, or osteomyelitis incidence. One study exploring the impact of arginine, glutamine and β-hydroxy-β-methylbutyrate supplement versus placebo did not report on any relevant outcomes.

AUTHORS' CONCLUSIONS

Evidence for the impact of nutritional interventions on the healing of foot ulcers in people with diabetes compared with no nutritional supplementation, or compared with a different dose of nutritional supplementation, remains uncertain, with eight studies showing no clear benefit or harm. It is also uncertain whether there is a difference in rates of adverse events, amputation rate, development of new foot ulcers, or quality of life, between nutritional interventions and placebo. More research is needed to clarify the impact of nutritional interventions on the healing of foot ulcers in people with diabetes.

Effect of Magnesium Supplementation on Circulating Biomarkers of Cardiovascular Disease

(1) Background: Magnesium supplementation may be effective for the prevention of cardiometabolic diseases, but the mechanisms are unclear. Proteomic approaches can assist in identifying the underlying mechanisms. (2) Methods: We collected repeated blood samples from 52 individuals enrolled in a double-blind trial which randomized participants 1:1 to oral magnesium supplementation (400 mg magnesium/day in the form of magnesium oxide) or a matching placebo for 10 weeks. Plasma levels of 91 proteins were measured at baseline with follow-up samples using the Olink Cardiovascular Disease III proximity extension assay panel and were modeled as arbitrary units in a log₂ scale. We evaluated the effect of oral magnesium supplementation for changes in protein levels and the baseline association between serum magnesium and protein levels. The Holm procedure was used to adjust for multiple comparisons. (3) Results: Participants were 73% women, 94% white, and had a mean age of 62. Changes in proteins did not significantly differ between the two intervention groups after correction for multiple comparisons. The most statistically significant effects were on myoglobin [difference −0.319 log₂ units, 95% confidence interval (CI) (−0.550, −0.088), p = 0.008], tartrate-resistant acid phosphatase type 5 (−0.187, (−0.328, −0.045), p = 0.011), tumor necrosis factor ligand superfamily member 13B (−0.181, (−0.332, −0.031), p = 0.019), ST2 protein (−0.198, (−0.363, −0.032), p = 0.020), and interleukin-1 receptor type 1 (−0.144, (−0.273, −0.015), p = 0.029). Similarly, none of the associations of baseline serum magnesium with protein levels were significant after correction for multiple comparisons. (4) Conclusions: Although we did not identify statistically significant effects of oral magnesium supplementation in this relatively small study, this study demonstrates the value of proteomic approaches for the investigation of mechanisms underlying the beneficial effects of magnesium supplementation. Clinical Trials Registration: ClinicalTrials.gov NCT02837328.

Circulating Ionized Magnesium: Comparisons with Circulating Total Magnesium and the Response to Magnesium Supplementation in a Randomized Controlled Trial

Ionized Mg (iMg) is considered the biologically active fraction of circulating total Mg (tMg). It is possible that iMg may be a more physiologically relevant marker than tMg. Using data from a double-blind pilot randomized controlled trial, we tested (1) whether oral Mg supplementation will increase iMg concentrations compared with placebo and (2) the relationship between iMg and tMg at baseline. Additionally, we evaluated the agreement between iMg measured in fresh whole blood versus stored samples. A total of fifty-nine participants were randomized 1:1 to oral Mg supplementation (400 mg/day, Mg Oxide) or placebo for 10 weeks. Fasting blood samples were obtained at baseline and follow-up. The analysis used linear regression and an intent-to-treat approach. Participants were generally healthy, the mean age was 62, and 73% were female. The baseline iMg and tMg were modestly and positively associated (r = 0.50). The ratio of baseline iMg to tMg was 64%. The mean supplement effect on iMg was 0.03 mmol/L (95% CI:0.01, 0.05) for Mg supplementation versus placebo. The supplement effect on iMg was not statistically significantly different according to baseline iMg status (above/below median). Compared to fresh blood, iMg was consistently higher in refrigerated and frozen samples by 0.14 and 0.20 mmol/L, respectively. In this relatively healthy adult population, Mg supplementation over 10 weeks resulted in increased iMg concentrations. Whether iMg is a more appropriate measure of Mg status than tMg, and the public health or clinical utility of measuring iMg remains to be determined.

Oral Magnesium Supplementation Improved Lipid Profile but Increased Insulin Resistance in Patients with Diabetic Nephropathy: a Double-Blind Randomized Controlled Clinical Trial

Low serum magnesium concentrations were associated with development of renal failure. We aimed to determine whether magnesium supplementation improves renal function, insulin resistance, and metabolic profiles in patients with diabetic nephropathy. A total of 80 hypomagnesemic patients diagnosed with type 2 diabetes and early-stage nephropathy were recruited. Subjects received either daily magnesium oxide or placebo for 12 weeks. Biochemical and anthropometric variables were measured. Physical activity and dietary intakes were also recorded. This study was approved by the ethics committee of Isfahan University of Medical Sciences and was registered on the Iranian Registry of Clinical Trials website (IRCT registration no. IRCT201404271485N12). Serum magnesium levels were not changed significantly. Although the supplementation did not influence glycemic indices, patients in the magnesium group had greater insulin resistance compared with the placebo group after intervention (0.3 ± 2.3 μIU/mL vs. - 0.04 ± 2.05, P = 0.04). No significant changes were observed in serum total cholesterol, triglycerides, HDL, LDL, and total cholesterol/HDL cholesterol ratio. Furthermore, magnesium did not affect inflammation, serum levels of creatinine, and blood urine nitrogen. However, a marginal decrease in microalbuminuria (- 3.1 ± 2.2 mg/L vs. - 14 ± 9.9, P = 0.09) was observed. Oral magnesium supplementation slightly improved microalbuminuria but resulted in increased insulin resistance in patients with diabetic nephropathy.

A Pilot Randomized Trial of Oral Magnesium Supplementation on Supraventricular Arrhythmias

Low magnesium may increase the risk of atrial fibrillation. We conducted a double-blind pilot randomized trial to assess adherence to oral magnesium supplementation (400 mg of magnesium oxide daily) and a matching placebo, estimate the effect on circulating magnesium concentrations, and evaluate the feasibility of using an ambulatory heart rhythm monitoring device (ZioPatch) for assessing premature atrial contractions. A total of 59 participants were randomized; 73% were women, and the mean age was 62 years. A total of 98% of the participants completed the follow-up. In the magnesium supplement group, 75% of pills were taken, and in the placebo group, 83% were taken. The change in magnesium concentrations was significantly greater for those given the magnesium supplements than for those given the placebo (0.07; 95% confidence interval: 0.03, 0.12 mEq/L; p = 0.002). The ZioPatch wear time was approximately 13 of the requested 14 days at baseline and follow-up. There was no difference by intervention assignment in the change in log premature atrial contractions burden, glucose, or blood pressure. Gastrointestinal changes were more common among the participants assigned magnesium (50%) than among those assigned the placebo (7%), but only one person discontinued participation. In sum, compliance with the oral magnesium supplementation was very good, and acceptance of the ZioPatch monitoring was excellent. These findings support the feasibility of a larger trial for atrial fibrillation (AF) prevention with oral magnesium supplementation.

Unprecedented Synergistic Effects of Nanoscale Nutrients on Growth, Productivity of Sweet Sorghum [Sorghum bicolor (L.) Moench], and Nutrient Biofortification

Evidence-based synergistic effects of nanoscale materials (size of <100 nm in at least one dimension) were scantly documented in agriculture at field scale. Herein, we report for the first time on effects of nanoscale zinc oxide (n-ZnO), calcium oxide (n-CaO), and magnesium oxide (n-MgO) on growth and productivity of sweet sorghum [Sorghum bicolor (L.) Moench]. A modified sol-gel method was used to prepare nanoscale materials under study. Characterization was performed using transmission and scanning electron microscopies, X-ray diffraction, and dynamic light scattering. Average sizes (25, 53.7, and 53.5 nm) and ζ potentials (-10.9, -28.2, and -16.2 mV) of n-ZnO, n-CaO, and n-MgO were measured, respectively. The significant grain yield (17.8 and 14.2%), cane yield (7.2 and 8.0%), juice yield (10 and 12%), and higher sucrose yield (21.8 and 20.9%) were recorded with the application of nanoscale materials in the years 2014 and 2015, respectively. Nutrient uptake was significant with foliar application of nanoscale nutrients.

Magnesium oxide use and reduced risk of dementia: a retrospective, nationwide cohort study in Taiwan

OBJECTIVE

Dietary magnesium may be associated with a lower risk of dementia; however, the impact of magnesium oxide (MgO), a common laxative, on dementia has yet to be elucidated. This study aimed to investigate the association between the usage of MgO and the risk of developing dementia.

METHODS

We used a dataset from the National Health Research Institute Database (NHRID) of Taiwan containing one million randomly sampled subjects to identify patients aged ≥50 years with no history of MgO usage. A total of 1547 patients who had used MgO were enrolled, along with 4641 controls who had not used the MgO propensity score matched by age, gender and comorbidity, at a ratio of 1:3. After adjusting for confounding risk factors, a Cox proportional hazards model was used to compare the risk of developing dementia during a 10 year follow-up period.

RESULTS

Of the enrolled patients, 44 (2.84%) developed dementia, when compared to 199 (4.28%) in the control group. The Cox proportional hazards regression analysis revealed that the patients who had used MgO were less likely to develop dementia with a crude hazard ratio of 0.617 (95% CI, 0.445-0.856, p = .004). After adjusting for age, gender, comorbidity, geographical area and urbanization level of residence, and monthly income, the adjusted hazard ratio was 0.517 (95% CI, 0.412-0.793, p = .001).

CONCLUSIONS

The patients who used MgO had a decreased risk of developing dementia. Further studies on the effects of MgO in reducing the risk of dementia are therefore warranted.

Modulating effect of MgO-SiO2 nanoparticles on immunological and histopathological alterations induced by aflatoxicosis in rats

INTRODUCTION

AflatoxinB1 (AFB1) is well-known as a feed borne-hepatotoxic and immunosuppressive mycotoxin. This study was conducted to evaluate the efficacy of nanocomposite magnesium oxide and silicon oxide (MgO-SiO₂) in reducing the toxic effects of AFB1on the immunity and histological alterations in liver, spleen and intestine of adult male rats.

EXPERIMENTAL DESIGN

Animals were divided into a control (Gp1) and three experimental groups (Gps); Gp2 received feed contained 200 ppb AFB1, Gp3 received feed contained 200 ppb AFB1 and 0.5 g/kg MgO-SiO₂ nanocomposite. While, rats of Gp4 received feed contained 0.5 g/kg MgO-SiO₂ nano-composite.

METHODS

Cellular and humoral immune responses, as well as histopathological examination and caspase-3 expression in liver, spleen, and intestine, were all evaluated. Residual concentration of AFB1was determined in serum, liver and fecal samples. The obtained data were statistically analyzed.

RESULTS

AFB1markedly reduced body weight gain and food and water consumption. Cellular immune response (total and differential leukocytes count, neutrophils' phagocytic activity, lymphocyte transformation, macrophage activity and serum lysozyme activity), serum total protein, and humoral immune response (fractions of protein as estimated by SDS- PAGE electrophoresis) were all severely reduced by AFB1. Moreover, AFB1induced marked histological alterations and apoptosis in liver, spleen, and intestine.

CONCLUSION

These findings suggested that the nanocomposite MgO-SiO₂ has high affinity to adsorb AFB1 and can effectively modulate its toxicity in rats.

IMPACT STATEMENT

Nanocomposite MgO-SiO₂ may offer a novel effective and cheap approach for the preventive management of aflatoxicosis in animals.

Dietary Supplementation of Magnesium Oxide (MgO) Nanoparticles for Better Survival and Growth of the Freshwater Prawn Macrobrachium rosenbergii Post-larvae

This study was performed to assess the growth-promoting potential of dietary magnesium oxide nanoparticles (MgO NPs) in Macrobrachium rosenbergii post-larvae (PL). MgO NPs were supplemented at 0, 100, 200, 300, 400 and 500 mg kg^-1 with the basal diet (containing 0.95 g Mg kg^-1); the concentrations of Mg in MgO NP-supplemented diets were increased correspondingly (1.07, 1.15, 1.24, 1.37 and 1.46 g Mg kg^-1 respectively). MgO NP-supplemented diets were fed to M. rosenbergii PL (initial weight 0.11 ± 0.04 g) for a period of 90 days. In the carcasses of experimental prawns, the content of Mg was found to be elevated significantly with respect to the individual diet (102.14, 183.29, 205.46, 221.03, 237.10 and 254.36 μg Mg g^-1 respectively) when compared with that of the control. The contents of Cu, Zn, Fe, Ca, Na and K levels were also found to be elevated in the carcasses of experimental prawns. Significant (P < 0.05) improvements were observed in nutritional indices [survival rate (SR), weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR) and protein efficiency ratio (PER)], activities of digestive enzymes (protease, amylase and lipase), concentrations of basic biochemical constituents (total protein, amino acid, carbohydrate, lipid, profiles of amino acids and fatty acids) and population of haemocytes [total and differential (hyalinocytes, semigranulocytes and granulocytes)] in all the test PL. Maximum performance was recorded in 500 mg kg^-1 MgO NP-supplemented-feed-fed PL. There were no significant elevations recorded in activities of antioxidant enzymes [superoxide dismutase (SOD) and catalase (CAT)], lipid peroxidation (LPO) and metabolic enzymes [glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT)] recorded in any of the MgO NP-supplemented-feed-fed PL when compared with the control. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed increases in the staining intensity of polypeptide bands resolved in 500 mg kg^-1 MgO NP-supplemented-feed-fed PL when compared with the control. Based on the gradual improvement in attaining survival, growth, FCR, biochemical constituents and haemocyte population, this study recommends MgO NP supplementation of 500 mg kg^-1 for sustainable maintenance of M. rosenbergii PL. As the studied highest concentration of MgO NPs showed the best performance, it is necessary to study with beyond 500 mg kg^-1 of MgO NPs to optimize the actual concentration.

Antacid attenuates the laxative action of magnesia in cancer patients receiving opioid analgesic

OBJECTIVE

This study was designed to investigate pharmacological interaction between magnesium laxative and antacid in patients receiving opioid analgesic.

METHODS

Data obtained from a total of 441 eligible patients receiving opioid analgesic for the first time were retrospectively analysed. The incidence of constipation, defined as stool-free interval of 3 days and more within the first week of opioid intake, was compared between patients who took laxative alone and those who received laxative in combination with antacid.

KEY FINDINGS

Laxatives were prescribed in 74% of patients, among them 61% received antacids such as proton pump inhibitor and H2 receptor blocker. Magnesia was the most commonly used laxative (89%). Constipation occurred in 21% and 55% of patients with and without laxatives, respectively. Antacids reversed the laxative action of lower doses (<2000 mg/day) but not higher doses (>2000 mg/day) of magnesia without affecting the effects of other laxatives. Therefore, it is suggested that both acid-dependent and acid-independent mechanisms may operate in the laxative action of magnesia, in which the former may be involved in the action of lower doses of magnesia.

CONCLUSION

Care should be taken to avoid the unfavourable pharmacological interaction between low doses of magnesia and antacid.

The effects of magnesium, L-carnitine, and concurrent magnesium-L-carnitine supplementation in migraine prophylaxis

Given the conflicting results about the positive effects of magnesium and L-carnitine and as there is no report concerning concurrent supplementation of magnesium and L-carnitine on migraine prophylaxis, the effects of magnesium, L-carnitine, and concurrent magnesium-L-carnitine supplementation on migraine indicators were assessed. In this clinical trial, 133 migrainous patients were randomly assigned into three intervention groups: magnesium oxide (500 mg/day), L-carnitine (500 mg/day), and Mg-L-carnitine (500 mg/day magnesium and 500 mg/day L-carnitine), and a control group. After 12 weeks of supplementation, the checklist of migraine indicators including migraine attacks/month, migraine days/month, and headache severity was completed, and serum concentrations of magnesium and L-carnitine were measured by atomic absorption spectrophotometry and enzymatic UV test, respectively. The results showed a significant reduction in all migraine indicators in all studied groups (p < 0.05). The ANOVA results showed a significant reduction in migraine frequency across various supplemented and control groups (p = 0.008). By separating the effects of magnesium supplementation from other confounding factors such as routine treatments using the repeated measures and nested model, it was clarified that magnesium supplementation had a significant effect on all migraine indicators. Oral supplementation with magnesium oxide and L-carnitine and concurrent supplementation of Mg-L-carnitine besides routine treatments could be effective in migraine prophylaxis; however, larger trials are needed to confirm these preliminary findings.

Magnesium supplementation through seaweed calcium extract rather than synthetic magnesium oxide improves femur bone mineral density and strength in ovariectomized rats

Commercially available seaweed calcium extract can supply high amounts of calcium as well as significant amounts of magnesium and other microminerals. The purpose of this study was to investigate the degree to which the high levels of magnesium in seaweed calcium extract affects the calcium balance and the bone status in ovariectomized rats in comparison to rats supplemented with calcium carbonate and magnesium oxide. A total of 40 Sprague-Dawley female rats (7 weeks) were divided into four groups and bred for 12 weeks: sham-operated group (Sham), ovariectomized group (OVX), ovariectomized with inorganic calcium and magnesium supplementation group (OVX-Mg), and ovariectomized with seaweed calcium and magnesium supplementation group (OVX-SCa). All experimental diets contained 0.5% calcium. The magnesium content in the experimental diet was 0.05% of the diet in the Sham and OVX groups and 0.1% of the diet in the OVX-Mg and OVX-SCa groups. In the calcium balance study, the OVX-Mg and OVX-SCa groups were not significantly different in calcium absorption compared to the OVX group. However, the femoral bone mineral density and strength of the OVX-SCa group were higher than those of the OVX-Mg and OVX groups. Seaweed calcium with magnesium supplementation or magnesium supplementation alone did not affect the serum ALP and CTx levels in ovariectomized rats. In summary, consumption of seaweed calcium extract or inorganic calcium carbonate with magnesium oxide demonstrated the same degree of intestinal calcium absorption, but only the consumption of seaweed calcium extract resulted in increased femoral bone mineral density and strength in ovariectomized rats. Our results suggest that seaweed calcium extract is an effective calcium and magnesium source for improving bone health compared to synthetic calcium and magnesium supplementation.

Calcium and Magnesium Supplementation Improves Serum OPG/RANKL in Calcium-Deficient Ovariectomized Rats

Magnesium (Mg) deficiency has been reported to result in increases in bone resorption through changes in the cytokine system, such as decreases in serum osteoprotegerin (OPG) concentrations and increases in receptor activator of NF-κB ligand (RANKL) concentrations. However, there are few data about the effects of Mg supplementation on OPG and RANKL. This study was carried out to investigate the effects of Mg supplementation on bone mineral density (BMD), bone mineral content (BMC), serum OPG, and RANKL in ovariectomized (OVX) rats relative to calcium (Ca) intake levels. Fifty-five Sprague-Dawley female rats were divided into the following five groups and fed for 12 weeks as indicated: sham-operated control group (sham), OVX Ca-deficient group (OLCa, 0.1% Ca and 0.05% Mg), OVX Ca-deficient and Mg-supplemented group (OLCaMg, 0.1% Ca and 0.1% Mg), OVX Ca-adequate group (OACa, 0.5% Ca and 0.05% Mg), and OVX Ca-adequate and Mg-supplemented group (OACaMg, 0.5% Ca and 0.1% Mg). The BMD of the lumbar spine, femur, and tibia in the OVX groups was significantly lower than that in the sham group. The OVX group with an adequate-Ca diet showed significantly higher BMC of the lumbar spine compared to the low Ca-diet group regardless of Mg supplementation. The OACaMg group had significantly higher levels of OPG and OPG/RANKL ratio than did the OLCa group. From the above results, it is still unclear whether Mg supplementation can improve bone mineral status, while Mg supplementation with an adequate-Ca diet resulted in a change in cytokines that may promote bone formation.

Effects of oral magnesium supplementation on insulin sensitivity and blood pressure in normo-magnesemic nondiabetic overweight Korean adults

BACKGROUND AND AIM

Little is known about the effect of magnesium on insulin sensitivity and BP in healthy individuals. Therefore, we investigated whether magnesium could improve insulin sensitivity and blood pressure (BP) in normo-magnesemic nondiabetic overweight adults.

METHODS AND RESULTS

In a double-blinded, placebo-controlled, randomized trial, a total of 155 participants (BMI > or = 23 kg/m(2)) received either 12.3 mmol (300 mg) of elemental magnesium in the form of magnesium oxide (n=75) or placebo (n=80) each day for 12 weeks, constituting the intent-to-treat population. A repeated-measures ANOVA was used to evaluate the between-group changes in variables during the study. The baseline characteristics between the intervention and control groups were similar. There were no significant differences between the groups in the pattern of change of the homeostasis model assessment insulin resistance index, BP over time during the 12-week study. In subgroup analysis, magnesium supplementation (n=8, 27, and 24, respectively) lowered BP much more than placebo (n=16, 29, and 25, respectively) in those subjects whose systolic BP > or = 140 mmHg, diastolic BP 80-90 mmHg, and diastolic BP > or = 90 mmHg at the start of the study (P=0.016, 0.043, and 0.023, respectively); in comparison, those subjects whose initial BP reading was low at baseline did not show a change in BP. No significant adverse events related to magnesium supplementation were recorded.

CONCLUSIONS

These results suggested that magnesium supplementation does not reduce BP and enhance insulin sensitivity in normo-magnesemic nondiabetic overweight people. However, it appears that magnesium supplementation may lower BP in healthy adults with higher BP.

Hypomagnesaemia due to use of proton pump inhibitors--a review

Magnesium homeostasis is essential for many intracellular processes and depends on the balance of intestinal absorption and renal excretion. Hypomagnesaemia may arise from various disorders. We review the literature on hypomagnesaemia due to the use of proton pump inhibitors, as illustrated by a case of a 76-year-old woman with muscle cramps and lethargy caused by hypomagnesaemia and hypocalcaemia with a low parathyroid hormone level while using esomeprazole, a proton pump inhibitor (PPI). After oral magnesium repletion both abnormalities resolved. Fractional magnesium excretion was low, excluding excessive renal loss. A causal relation with PPI use was supported by the recurrence of hypomagnesaemia after rechallenge. In the past decade our understanding of transcellular magnesium transport was enhanced by the discovery of several gene mutations i.e. transient receptor potential melastin (TR PM) 6 and 7. In this light we discuss the possible aetiology of proton pump inhibitor related hypomagnesaemia.

Effects of source and level of magnesium on catalase activity and its gene expression in livers of broiler chickens

The effects of dietary supplemental magnesium oxide (MgO), magnesium-L-aspartate (MgAsp) and monomagnesium-di-L-aspartate (MgdiAsp) on hepatic catalase (CAT) activity and its mRNA expression were investigated. A total of 360 one-day-old male Abor Acre broiler chickens were allocated to ten treatments, i.e. control plus 9 treatments from 3 x 3 factorial arrangement (Mg source, Mg level), each treatment with six replicates of 6 chickens. The birds were fed with the basal diet alone or supplemented with magnesium (Mg) at 0.9, 1.8, 2.7 g/kg of the diet from MgO, MgAsp or MgdiAsp. Results showed that hepatic Mg concentration increased quadratically as MgO or MgAsp supplementation increased (p < 0.01). Hepatic CAT activity increased linearly in birds fed with MgAsp or MgdiAsp (p < 0.01) and quadratically in birds fed with MgO (p < 0.05) as dietary Mg supplementation level increased. Hepatic CAT mRNA was linearly correlated with the dietary Mg supplementation level (p < 0.01). There were positive correlations among hepatic CAT activity, its mRNA expression level and hepatic Mg concentration (p < 0.01). No effect of Mg2+ on the purified CAT activity was detected in vitro enzymatic reaction system (p > 0.05). Supplemental MgAsp or MgdiAsp was more efficient to increase hepatic Mg concentrations, enhance hepatic CAT activity and its mRNA expression than MgO (p < 0.01). It can be concluded that dietary Mg supplementation could increase hepatic Mg concentration, enhance CAT mRNA expression and consequently enhance CAT activity, and the organic Mg (MgAsp or MgdiAsp) is much more efficient than the inorganic form (MgO).

[Causes and treatment of hypomagnesemia]

Plasma magnesium (Mg) is known to be maintained within a normal range through its gastrointestinal absorption as well as renal excretion, and disturbances at these sites might cause hypomagnesemia. Mg balance is most susceptible to the malfunction of the thick ascending limb of renal tubules, because 70% of urinary Mg excretion is reabsorbed from this site. Investigation of hypomagnesemia-exhibiting inherited diseases revealed molecular mechanisms of Mg transport pathways; paracellin-1 as a passive paracellular transport and TRPM6 as an active transcellular transport. Mild and severe hypomagnesemia are treated with oral replacement such as magnesium oxide, as well as intravenous administration of magnesium sulfate.

A randomized controlled study of effects of dietary magnesium oxide supplementation on bone mineral content in healthy girls

CONTEXT

The role of magnesium (Mg) as a determinant of bone mass has not been extensively explored. Limited studies suggest that dietary Mg intake and bone mineral density are correlated in adults, but no data from interventional studies in children and adolescents are available.

OBJECTIVE

We sought to determine whether Mg supplementation in periadolescent girls enhances accrual of bone mass.

DESIGN

We carried out a prospective, placebo-controlled, randomized, one-year double-blind trial of Mg supplementation.

SETTING

The study was conducted in the Clinical Research Centers at Yale University School of Medicine.

PATIENTS OR OTHER PARTICIPANTS

Healthy 8- to 14-yr-old Caucasian girls were recruited from community pediatricians' offices. Dietary diaries from over 120 volunteers were analyzed, and those with dietary Mg intake of less than 220 mg/d were invited to participate in the intervention.

INTERVENTION

Magnesium (300 mg elemental Mg per day in two divided doses) or placebo was given orally for 12 months.

MAIN OUTCOME MEASURE

The primary outcome measure was interval change in bone mineral content (BMC) of the total hip, femoral neck, Ward's area, and lumbar spine (L1-L4) after 12 months of Mg supplementation.

RESULTS

Significantly increased accrual (P = 0.05) in integrated hip BMC occurred in the Mg-supplemented vs. placebo group. Trends for a positive Mg effect were evident in the pre- and early puberty and in mid-late puberty. Lumbar spinal BMC accrual was slightly (but not significantly) greater in the Mg-treated group. Compliance was excellent; 73% of capsules were ingested as inferred by pill counts. Serum mineral levels, calciotropic hormones, and bone markers were similar between groups.

CONCLUSIONS

Oral Mg oxide capsules are safe and well tolerated. A positive effect of Mg supplementation on integrated hip BMC was evident in this small cohort.

Effect of a metabolically created systemic acidosis on calcium homeostasis and the diurnal variation in urine pH in the non-lactating pregnant dairy cow

Reducing the dietary cation-anion difference (DCAD) has been shown to be an effective means of preventing parturient paresis in confinement systems where cows are offered a total mixed ration containing DCAD-reducing mineral compounds (anionic salts). Such a supplementation strategy is not possible in cows being group fed forages precalving, and little is known about the effect of supplementing these cows with large amounts of anionic salts twice daily.

Eight non-lactating, pregnant Holstein-Friesian cows were allocated to two levels of DCAD (−20 and +18 meq/100 g DM) for 24 d, with an intensive Ca balance undertaken in metabolism stalls following a 2-week acclimatization to diet. The basal diet was 3 kg DM of crushed barley and 7 kg DM of pasture-hay. Urine and faeces were collected separately, weighed daily for 5 d and analysed for Ca content. Urinary Ca, creatinine and hydroxyproline concentration and plasma Ca concentration were determined during the period of the balance study. The diurnal pattern in urine and rumen pH was determined over 2 d. Decreasing DCAD reduced (P<0·001) the pH of urine, and increased (P<0·05) Ca absorption. Plasma Ca concentration was not affected by DCAD, and DCAD did not affect the output of urinary hydroxyproline, a marker of bone resorption. Twice-daily supplementation of anionic salts was sufficient to reduce the pH of blood and increase gastrointestinal Ca absorption. There was no diurnal variation in the pH of urine, suggesting that time of sampling to determine efficacy of DCAD in reducing systemic pH was not important.

A randomized, prospective, comparison study of polyethylene glycol 3350 without electrolytes and milk of magnesia for children with constipation and fecal incontinence

OBJECTIVE

Our aim was to compare 2 laxatives, namely, polyethylene glycol 3350 without electrolytes and milk of magnesia, evaluating the efficacy, safety, acceptance, and 1-year outcomes.

METHODS

Seventy-nine children with chronic constipation and fecal incontinence were assigned randomly to receive polyethylene glycol or milk of magnesia and were treated for 12 months in tertiary care pediatric clinics. Children were counted as improved or recovered depending on resolution of constipation, fecal incontinence, and abdominal pain after 1, 3, 6, and 12 months. An intent-to-treat analysis was used. Safety was assessed with evaluation of clinical adverse effects and blood tests.

RESULTS

Thirty-nine children were assigned randomly to receive polyethylene glycol and 40 to receive milk of magnesia. At each follow-up visit, significant improvement was seen in both groups, with significant increases in the frequency of bowel movements, decreases in the frequency of incontinence episodes, and resolution of abdominal pain. Compliance rates were 95% for polyethylene glycol and 65% for milk of magnesia. After 12 months, 62% of polyethylene glycol-treated children and 43% of milk of magnesia-treated children exhibited improvement, and 33% of polyethylene glycol-treated children and 23% of milk of magnesia-treated children had recovered. Polyethylene glycol and milk of magnesia did not cause clinically significant side effects or blood abnormalities, except that 1 child was allergic to polyethylene glycol.

CONCLUSIONS

In this randomized study, polyethylene glycol and milk of magnesia were equally effective in the long-term treatment of children with constipation and fecal incontinence. Polyethylene glycol was safe for the long-term treatment of these children and was better accepted by the children than milk of magnesia.

A phase I/II trial of irinotecan-cisplatin combined with an anti-late-diarrhoeal programme to evaluate the safety and antitumour response of this combination therapy in patients with advanced non-small-cell lung cancer

We conducted a phase I/II study in patients with advanced non-small-cell lung cancer (NSCLC) to increase the therapeutic index of the cisplatin–irinotecan combination by institution of an anti-late-diarrhoeal program (ADP). A total of 77 chemotherapy-naive patients with advanced NSCLC were enrolled. The cisplatin dose was fixed at 60 mg m⁻² (Day 1). Irinotecan was escalated in 5 mg m⁻² increments, starting from 60 mg m⁻² (Days 1 and 8). ADP consisted of oral sodium bicarbonate, magnesium oxide, basic water, and ursodeoxycholic acid, and was administered orally for 4 days with each dose of irinotecan. In the phase I portion, irinotecan pharmacokinetics was also examined. After the recommended dose of irinotecan with ADP was determined, a phase II study was conducted to evaluate the response. Maximum tolerated dose was reached at an irinotecan dose of 80 mg m⁻² (Grade 4 diarrhoea and neutropenia). Pharmacokinetic studies show that the maximum concentration and the area under the curve of both irinotecan and SN38 (active metabolite of irinotecan) tend to increase in the dose-dependent manner of irinotecan. The phase II portion of the study included 48 patients, who were treated with 75 mg m⁻² of irinotecan. Grade 3/4 toxicities included neutropenia in 65%, leucopenia in 33%, and late diarrhoea in 6% of the patients. During this treatment, PS did not change in 65% of patients. At the end of the chemotherapy, PS did not decline in 90% of patients. In the phase II portion, a response occurred in 63% (95% confidential interval (CI), 47–76%) of patients. Median time to progression was 19 weeks (95% CI, 15–22 weeks), and median survival was 52 weeks (95% CI, 39–64 weeks). This regimen of irinotecan and cisplatin with ADP resulted in promising efficacy with acceptable toxicity for patients with advanced NSCLC. This regimen is a candidate for the experimental arm towards future phase III studies.

[The results of application of magnesium-bearing medications and different load doses of vitamins B1 and B2 in volunteers]

Presently is no consensus of opinion of the size of human optimal daily allowance as for thiamine and riboflavin, so for magnesium, what their content in polyvitamin and mineral preparations testify to. The study was conducted in 60 volunteers, who once took oral dosing of magnesium -bearing preparation "Magnerot" (500 mg of magnesium orotat converting to Mg2+ 32,8 Mg) and "Centrum" (100 mg of magnesium oxide converting to Mg2+ - 60,3 Vg) or vitamins B1 and B2 in 10, 20 and 30 mg doses. The received data testify that during the application of both of these preparations, equal concentration of this element takes place, though in case of magnesium oxide it happens later. As for the used vitamin B1 and B2 doses, it is determined that 10 mg is the optimal dose for treating their hypoavitaminosis.

Grass tetany in a herd of beef cows

Five cows in a herd of 15 cattle that had just been turned out onto lush pasture after having over-wintered on poor quality hay died suddenly. Biochemical profiles collected from the cadavers revealed reduced serum levels of magnesium, urea, and beta-hydroxybutycate. Classical grass tetany (hypomagnesemia) was diagnosed on postmortem examination.

Magnesium proteinate is more protective than magnesium oxide in heat-stressed quail

We evaluated the effects of dietary supplementation with Mg-oxide and Mg-proteinate on performance; nutrient digestibilities; malondialdehyde (MDA) concentrations in serum, liver, and thigh meat; and serum cholesterol and triacylglycerol concentrations in Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature. The birds (n = 360; 10 d old) were randomly assigned to 12 treatment groups consisting of 6 replicates of 5 birds each in a 2 x 2 x 3 factorial arrangement (temperature, Mg source, Mg level). Birds were maintained in temperature-controlled rooms at 22 degrees C for 24 h/d or 34 degrees C for 8 h/d (0900-1700 h) and fed a basal diet or that diet supplemented with 1 or 2 g Mg-oxide or Mg-proteinate/kg of diet. Heat exposure decreased (P = 0.0001) live weight gain, feed intake, feed efficiency, and carcass weight in quail fed the basal diet. A linear increase in feed intake (P = 0.008) and body weight (P = 0.001), and improvements in feed efficiency (P = 0.001), carcass weight (P < 0.0001), digestibility of dry matter, organic matter, crude protein, and ether extract were found in Mg-supplemented, heat-stressed quail. The effects of Mg-proteinate were greater than those of Mg-oxide (P < or = 0.0001). Serum Mg (P = 0.001) concentration increased, whereas the concentration of MDA in serum (P = 0.0001), liver (P = 0.04), and thigh meat (P = 0.0001) and serum triglyceride and cholesterol concentrations decreased linearly (P = 0.001) with the level of Mg in the diet. Interactions between dietary Mg source, temperature, and level of supplementation (P < or = 0.05) were found for several variables. Results of the present study suggest that supplementation with Mg-proteinate is more protective than Mg-oxide in reducing the negative effects of heat stress in quail.

Management of constipation in residents with dementia: sorbitol effectiveness and cost

OBJECTIVE

The objective of this report is to describe a cost-effective strategy for management of constipation in nursing home residents with dementia.

DESIGN

We conducted a prospective observational quality improvement study of 41 residents with chronic constipation and receiving an osmotic laxative. Sorbitol was substituted for lactulose.

SETTING

The study was conducted at a dementia special care unit at a Veterans Administration hospital.

MEASUREMENT

We measured the number and amount of laxative use over a period of 4 weeks that were required to maintain regular bowel function.

RESULTS

There was no difference in efficacy of lactulose and sorbitol. Use of additional laxatives was infrequent: Milk of Magnesia on approximately 10% of days/patient, bisacodyl suppository on 2% to 4% of days/patient, and Fleet enema only on 3 occasions. The cost of constipation management using routine administration of sorbitol and as-needed use of other laxatives was 27% to 55% lower than the cost of other constipation management strategies reported in the literature.

CONCLUSION

Substitution of sorbitol for lactulose does not change efficacy of the treatment and decreases cost. Regular use of an osmotic laxative avoids the costs and discomforts of rectal laxatives.

Weekly administration of irinotecan (CPT-11) plus cisplatin for refractory or relapsed small cell lung cancer

PURPOSE

Weekly administrations of CPT-11 plus cisplatin together with an anti-diarrheal program, the Oral Alkalization and Control of Defecation [Int J Cancer 1999;83:491; Int J Cancer 2001;92:269; Cancer Res 2002;62:179], were evaluated in this phase II study for patients with refractory or relapsed small cell lung cancer.

METHODS

Patients were treated by weekly administrations of 60 mg/m(2) CPT-11 plus 30 mg/m(2) cisplatin on Days 1, 8 and 15 over 4 weeks. Coinciding with the infusions and for 4 days thereafter, the anti-diarrheal program was practiced using orally administered sodium bicarbonate, magnesium oxide and basic water.

RESULTS

Twenty-five patients who had prior treatments of etoposide and platinum containing regimens (16 refractory patients and nine relapsed patients) were entered. The mean dose-intensities of CPT-11 and cisplatin were 154.8 and 77.4 mg/m(2) per course, respectively. Therefore, 86% of the planned dose was delivered. There were 20 partial responses and an overall response rate of 80% (95% confidence interval, 62-96%) was obtained. The median time to progression and the median survival after starting this regimen were 3.6 and 7.9 months, respectively. The major toxicity was myelosuppression. Grades 3 and 4 neutropenia occurred in 24 and 12% of patients, respectively. One patient with febrile neutropenia was experienced, and Grade 3 diarrhea was observed in 8%. But there was no treatment death.

CONCLUSION

Weekly administrations of CPT-11 plus cisplatin together with Oral Alkalization and Control of Defecation provide a practical and well tolerated regimen that was active for refractory or relapsed small cell lung cancer.

Changes in urinary parameters after oral administration of potassium-sodium citrate and magnesium oxide to prevent urolithiasis

OBJECTIVES

To examine urinary parameters among normal individuals and patients with calcium oxalate (CaOx) stones after oral administration of potassium-sodium citrate (KNa-Cit) and magnesium oxide (MgO). Urinary citrate and magnesium have been known as the inhibitors of CaOx stone formation. Supplementation with potassium-magnesium citrate prevents the recurrence of CaOx stones.

METHODS

Twenty-five male volunteers aged 21 to 42 years without a history of urinary stones were given either KNa-Cit or MgO, or both. Fourteen patients with recurrent CaOx stones were also given both supplements, and 24-hour urine samples were collected to determine the urinary parameters.

RESULTS

The administration of both KNa-Cit and MgO to the normal individuals increased the excretion of citrate, magnesium, and potassium by 70.0%, 44.2%, and 50.0%, respectively. These parameters increased less when KNa-Cit or MgO was administered individually. After administration of both supplements to the patients with stones, the citrate, magnesium, and potassium levels increased by 62.1%, 63.3%, and 25.3%, respectively, and oxalate decreased by 66.5%. In both normal individuals and patients, the ion activity product index of CaOx decreased significantly more after administration of the combination than with either compound alone or before administration.

CONCLUSION

The combination of KNa-Cit and MgO is more effective than either supplement alone in inhibiting the crystallization of CaOx stones. The combination may improve the urinary parameters of patients with stones accompanied by hypocitraturia and/or hypomagnesuria.

[Two cases of encrusted cystitis]

Encrusted cystitis is a type of severe cystitis, which progresses chronically and is characterized by excessively alkaline urine and calcifications within the bladder wall. We report two cases of encrusted cystitis. Both cases were high aged and had severe anemia with chronic cystitis. They complained of gross hematuria, voiding frequency and pain upon urination. Urine pH was 8-9, and urine cytology was negative. Urine culture contained Corynebacterium Group D2. Abdominal computed tomography and transurethral resection revealed wall bladder wall calcification and inflammatory change. We diagnosed it as encrusted cystitis. The patients underwent excision of plaques of calcified encrustation, adapted antibiotic therapy and acidification of urine. It is essential to diagnose encrusted cystitis early and to provide adequate treatment promptly.

Oral magnesium oxide prophylaxis of frequent migrainous headache in children: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To assess whether, in children, oral magnesium oxide reduces migrainous headache frequency, severity, and associated features compared to placebo.

BACKGROUND

There is no single, safe, widely well-tolerated, and effective prophylactic treatment for all children and adolescents with frequent migrainous headache.

DESIGN

Randomized, double-blind, placebo-controlled, parallel-group trial.

METHODS

This study was conducted between June 1997 and January 2000 using 7 selected Northern California Kaiser Permanente sites. We recruited children of ages 3 to 17 years who reported a 4-week history of at least weekly, moderate-to-severe headache with a throbbing or pulsatile quality, associated anorexia/nausea, vomiting, photophobia, sonophobia, or relief with sleep, but no fever or evidence of infection. Subjects were randomly assigned to receive either magnesium oxide (9 mg/kg per day by mouth divided 3 times a day with food) (n = 58) or matching placebo (n = 60) for 16 weeks. The number of headache days (days with at least one headache) during each of eight 2-week intervals was chosen to be the primary outcome variable.

RESULTS

Of those enrolled, 86 (73%) completed the study (42 received magnesium oxide and 44 placebo); 74 of 192 eligible subjects declined to participate. Baseline information on demographic factors, health status, and headache history was similar comparing the 2 groups. By intention-to-treat analysis, we found a statistically significant decrease over time in headache frequency in the magnesium oxide group (P =.0037) but not in the placebo group (P =.086), although the slopes of these 2 lines were not statistically significantly different from each other (P =.88). The group treated with magnesium oxide had significantly lower headache severity (P =.0029) relative to the placebo group.

CONCLUSIONS

This study does not unequivocally determine whether oral magnesium oxide is or is not superior to placebo in preventing frequent migrainous headache in children, but treatment with the active agent did lead to a significant reduction in headache days. Larger trials involving this safe, appealing complementary therapy are needed.

The incidence and control of hypocalcaemia in pasture-based systems

A large emphasis on precalving magnesium supplementation has substantially reduced the incidence of clinical hypocalaemia in pasture-based systems. Survey data in the major pasture-based systems suggest a 2 to 4% incidence of parturient paresis, although this can vary considerably between farms. Detailed blood measurements under research conditions suggests that approximately 5% of cows are clinically hypocalcaemic (blood calcium < 1.4 mmol/l) and between 30 and 40% of cows are subclinically hypocalcaemic (plasma calcium < 2.0 mmol/l). Systems of control have traditionally been based on preventing the paretic cow, with more emphasis of late being placed on preventing hypocalcaemia. Preventative measures vary, but largely involve either supplementation with magnesium oxide pre-calving, supplementation with calcium carbonate during the colostrum period or a combination of magnesium supplementation precalving and calcium supplementation post-calving. In New Zealand, the use of commercial products that bind calcium is increasing precalving, but is still only practiced by a small percentage of farmers. The dietary cation-anion difference (DCAD) of pasture is so high and so variable that changes in DCAD sufficient to change blood pH are not practical and very difficult to achieve with consistency. The use of magnesium chloride and magnesium sulphate in preference to magnesium oxide, as precalving magnesium supplements, is increasing.

[A case of urolithiasis associated with short bowel syndrome]

We report a case of urolithiasis associated with short bowel syndrome. A 56-year-old woman was admitted to our hospital for asymptomatic bilateral renal stones. She had received extensive resection of small intestine due to strangulating obstructive ileus 7 years ago (residual intestine, only 20 cm). Subsequently, she was in a state of short bowel syndrome. Plain film of kidney, uteter, bladder and computed tomography revealed bilateral renal stones (right 4 mm, left 10 mm). The left renal stone was successfully treated by extracorporeal shock wave lithotripsy. Since the right renal stone was small, no treatment was performed. The stone fragments were composed of calcium oxalate and calcium phosphate, and excessive urinary excretion of oxalate (103.8 mg/day) was observed. In this patient, urolithiasis was diagnosed to be due to enteric hyperoxaluria caused by short bowel syndrome. To prevent the recurrence of stone formation, she was treated with oral administration of calcium lactate, sodium/potassium citrate and magnesium oxide. We review the Japanese literatures on urolithiasis with short bowel syndrome.

[A case-control study of prevention of irinotecan-induced diarrhea: the reducing side effects of irinotecan by oral alkalization combined with control of defecation]

Irinotecan and its active metabolite, SN-38, were reported to have the absorption characteristics of weakly basic drugs. Moreover, stasis of these compounds is thought to induce damage to the intestinal mucous membrane. The purpose of this report was to examine whether oral alkalization (OA) combined with control of defecation (CD) might prevent irinotecan-induced side effects. From day one of irinotecan infusion to day four, OA & CD were practiced using orally administered sodium bicarbonate, magnesium oxide, basic water, and ursodeoxycholic acid. Thirty-two lung cancer patients were treated with irinotecan in combination with cisplatin in the absence of OA & CD (Group A). Thirty-seven patients matched for background characteristics were treated with the same regimen in the presence of OA & CD (Group B). Group B had a reduced incidence of delayed diarrhea (Grade 2 < or = Group A 32.3% vs. Group B 9.4%), nausea, vomiting, and myelotoxicity, especially granulocytopenia compared with Group A. In addition, dose intensification was well-tolerated in Group B. Tumor response rates for non-small cell lung cancer were 59.3% (16/27 patients) in Group B against 38.5% (10/26 patients) in Group A. OA & CD appears to reduce the irinotecan-induced side effects, especially delayed diarrhea. Risk factors statistically associated with delayed diarrhea include advanced age and the use of irinotecan without OA & CD.

Use of cisapride with magnesium oxide in chronic pediatric constipation

Functional constipation in children is a common problem in daily practice, however there is currently no accepted optimal treatment of choice. This study investigated the effect of cisapride in the treatment of pediatric constipation when combined with magnesium oxide (MgO). This prospective study enrolled children with chronic constipation. They were randomly assigned to either MgO (125 mg three times a day for patients weighing less than 20 kg or 250 mg three times a day for those weighing more than 20 kg), or cisapride 0.2 mg/kg (max 5mg/dose) plus MgO for 4 weeks. Twenty-one doctors in 19 major medical centers or hospitals in Taiwan with well- established pediatric departments participated in this study from October 1999 to March 2000. 84 children (51 males, 33 females, 1-7 years of age) with fewer than 2 spontaneous bowel movements per week for at least one month completed the study. After 1 week of therapy, a good response, defined as 3 or more bowel movements per week, was achieved in 30 (68.2%) of children treated with cisapride and MgO compared with 23 (57.5%) children treated with MgO alone (p=n.s.). At the end of the 4-week treatment period, 90.9% of the children in cisapride group compared with 67.5% of the children in MgO group achieved a good response (p=0.013). There was no statistical difference between the two groups in terms of the side effects and stool characteristics. In conclusion, it appears that cisapride in combination with MgO may have a synergistic effect and improves the frequency of stool passage in pediatric functional constipation.

Physicochemical characterization and evaluation of buccal adhesive tablets containing omeprazole

The objective of this study was to develop an effective omeprazole buccal adhesive tablet with excellent bioadhesive force and good drug stability in human saliva. The omeprazole buccal adhesive tablets were prepared with various bioadhesive polymers, alkali materials, and croscarmellose sodium. Their physicochemical properties, such as bioadhesive force and drug stability in human saliva, were investigated. The release and bioavailability of omeprazole delivered by the buccal adhesive tablets were studied. As bioadhesive additives for the omeprazole tablet, a mixture of sodium alginate and hydroxypropylmethylcellulose (HPMC) was selected. The omeprazole tablets prepared with bioadhesive polymers alone had bioadhesive forces suitable for a buccal adhesive tablet, but the stability of omeprazole in human saliva was not satisfactory. Among alkali materials, only magnesium oxide could be an alkali stabilizerfor omeprazole buccal adhesive tablets due to its strong waterproofing effect. Croscarmellose sodium enhanced the release of omeprazole from the tablets; however, it decreased the bioadhesive forces and stability of omeprazole tablets in human saliva. The tablet composed of omeprazole/sodium alginate/HPMC/magnesium oxide/croscarmellose sodium (20/24/6/50/10 mg) could be attached on the human cheek without disintegration, and it enhanced the stability of omeprazole in human saliva for at least 4 h and gave fast release of omeprazole. The plasma concentration of omeprazole in hamsters increased to a maximum of 370 ng/ml at 45 min after buccal administration and continuously maintained a high level of 146-366 ng/ml until 6 h. The buccal bioavailability of omeprazole in hamsters was 13.7% +/- 3.2%. These results demonstrate that the omeprazole buccal adhesive tablet would be useful for delivery of an omeprazole that degrades very rapidly in acidic aqueous medium and undergoes hepatic first-pass metabolism after oral administration.

Beneficial antithrombotic effects of the association of pharmacological oral magnesium therapy with aspirin in coronary heart disease patients

The use of magnesium in the treatment of acute myocardial infarction remains controversial despite preliminary experimental evidence that magnesium plays a beneficial role as a regulator of thrombosis. The aim of our study was to determine whether oral magnesium treatment inhibits platelet-dependent thrombosis (PDT) in stable patients with coronary artery disease (CAD). In a randomized prospective, double-blind, cross-over and placebo controlled study, 42 patients with stable CAD (37 men, 5 women, mean age 68 +/- 9 years) on aspirin received either magnesium oxide tablets (800-1,200 mg/day) or placebo for 3 months (Phase 1) followed by a 4-week washout period, and the cross-over treatment for 3 months (Phase 2). PDT, platelet aggregation, platelet P-selectin flow-cytometry, monocyte tissue factor procoagulant activity (TF-PCA) and adhesion molecules density were assessed before and after each phase. PDT was evaluated by an ex-vivo perfusion model using the Badimon chamber. Median PDT was significantly reduced by 35 percent in patients who received magnesium versus placebo (D change from baseline: -24 vs. 26 microm2/mm; p = 0.02, respectively). There was no significant effect of magnesium treatment on platelet aggregation, P-selectin expression, monocyte TF-PCA or adhesion molecules. Oral magnesium treatment inhibits PDT in patients with stable CAD. This effect appears to be independent of platelet aggregation or P-selectin expression, and is evident despite aspirin therapy. These findings suggest a potential mechanism whereby magnesium may beneficially alter outcomes in patients with CAD.

Effect of oral magnesium supplementation on blood pressure, platelet aggregation and calcium handling in deoxycorticosterone acetate induced hypertension in rats

OBJECTIVE

To study the effect of oral magnesium supplementation on blood pressure, platelet aggregation and platelet calcium handling in deoxycorticosterone acetate (DOCA)-induced hypertension in rats.

DESIGN AND METHODS

Rats were divided into four groups of 20 each. Drug treatments were given for a 6-week period. Control rats were vehicle treated. In the second group, DOCA, 15 mg/kg, was injected subcutaneously twice weekly with 1% NaCl used instead of drinking water. The third group was given magnesium oxide (MgO), 1 g/kg daily, orally by gavage. The fourth group was given MgO along with DOCA and 1% NaCl. Blood pressure and heart rate were measured weekly. Platelet aggregation, intracellular calcium, calcium uptake and calcium efflux studies were performed at the end of sixth week. Serum magnesium concentration, plasma levels of reactive nitrogen intermediates (RNI) and citrulline were also measured

RESULTS

There was a significant rise in blood pressure in the DOCA-treated rats. Magnesium prevented the gradual rise in blood pressure when given along with DOCA, but had no effect in normotensive rats. Heart rate did not show any significant change. Platelet aggregation was significantly reduced in all the treatment groups compared to the control group. DOCA treatment produced a significant increase in the intracellular calcium concentration as well as the calcium uptake compared to the control group. Magnesium supplementation inhibited the increased intracellular calcium concentration and calcium uptake in DOCA-treated rats. RNI and citrulline levels were elevated in all the treatment groups. Serum magnesium levels were significantly higher in the magnesium-treated and DOCA plus magnesium-treated rats.

CONCLUSIONS

Magnesium supplementation prevents blood pressure elevation in DOCA hypertensive rats. These effects are associated with inhibition of platelet calcium uptake and decreased intracellular free calcium concentration.

Oral magnesium supplementation inhibits platelet-dependent thrombosis in patients with coronary artery disease

The use of magnesium in the treatment of acute myocardial infarction remains controversial despite preliminary experimental evidence that magnesium plays a beneficial role as a regulator of thrombosis. This study examines whether oral magnesium treatment inhibits platelet-dependent thrombosis (PDT) in patients with coronary artery disease (CAD). In a randomized prospective, double-blind, crossover, and placebo-controlled study, 42 patients with CAD (37 men, 5 women, mean age 68 +/- 9 years) on aspirin received either magnesium oxide tablets (800 to 1,200 mg/day) or placebo for 3 months (phase 1) followed by a 4-week wash-out period, and the crossover treatment for 3 months (phase 2). PDT, platelet aggregation, platelet P-selectin flow cytometry, monocyte tissue factor procoagulant activity (TF-PCA), and adhesion molecule density were assessed before and after each phase. PDT was evaluated by an ex vivo perfusion model using the Badimon chamber. Median PDT was significantly reduced by 35% in patients who received magnesium versus placebo (delta change from baseline -24 vs 26 mm2/mm; p = 0.02, respectively). There was no significant effect of magnesium treatment on platelet aggregation, P-selectin expression, monocyte TF-PCA, or adhesion molecules. Oral magnesium treatment inhibited PDT in patients with stable CAD. This effect appears to be independent of platelet aggregation or P-selectin expression, and is evident despite aspirin therapy. These findings suggest a potential mechanism whereby magnesium may beneficially alter outcomes in patients with CAD.

Percutaneous chemolysis--an important tool in the treatment of urolithiasis

Persistent residual calculi after therapy, i.e. extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolitholapaxy (PNL), as well as pyelo- and nephrolithotomy are big problems in the treatment of urolithiasis. Furthermore, the therapy of stones is problematic in patients with inadequate drainage, impaired kidney function, or with high risks against anaesthetics. Between 1991 and 1997 percutaneous antegrade chemolysis was carried out in eleven patients. In nine of them complete dissolution of stones was achieved. In two further cases, in which calcium oxalate was the main component of the stones, chemolysis was unsuccessful. Through our own cases and under consideration of the literature, we will show that percutaneous chemolysis in these cases is useful and effective in the treatment of urolithiasis.

Primary hypomagnesemia caused by isolated magnesium malabsorption: atypical case in adult

Isolated magnesium malabsorption is a rare disorder, which bas been described in no more than 30 patients worldwide. Patients with this disorder typically present with convulsion and diarrhea in early infancy. Hypomagnesemia and hypocalcemia were found in a 35-year-old man with muscle cramps, who bad been diagnosed as primary hypoparathyroidism. Oral magnesium therapy corrected the low serum calcium, magnesium and parathyroid hormone levels. We report an atypical case of isolated magnesium malabsorption in an adult.

[Antitoxic features of magnesium oxide under combined radiation and thermal injury]

Male Wistar rats were exposed to 7.5 Gy total body gamma radiation followed to the additional full-thickness thermal bum. It was shown, that single administration of magnesium oxide in 1 hour after combined injury significantly corrected the early signs of endogenous intoxication. The level of bacterial endotoxemia decreased as well as serum concentration of toxic oligopeptides; general blood serum toxicity has been reduced too. Four-fold magnesium oxide's using as an enterosorbent in combination with antibiotics (doxycyclini, gentamicini or ciprofloxacin) has ensured 73-100% rats survival. All untreated animals dead within 30 days after combined injury.

High-dose pyridoxine and magnesium administration in children with autistic disorder: an absence of salutary effects in a double-blind, placebo-controlled study

Several reports have described salutary effects such as decreased physical aggression and improved social responsiveness being associated with the administration of high doses of pyridoxine and magnesium (HDPM) in open-labeled and controlled studies of patients with autism. Despite this fact, this intervention remains controversial. A 10-week double-blind, placebo-controlled trial was undertaken to examine both the efficacy and safety of HDPM in autism. Twelve patients were enrolled, and 10 patients (mean age 6 years 3 months) were able to complete the study. HDPM at an average dose of 638.9 mg of pyridoxine and 216.3 mg of magnesium oxide was ineffective in ameliorating autistic behaviors as assessed by the Children's Psychiatric Rating Scale (CPRS), the Clinical Global Impression Scale, and the NIMH Global Obsessive Compulsive Scale. Furthermore, no clinically significant side effects were noted during HDPM administration. A trend for a transient change on the CPRS was found that was possibly due to a placebo response. This study raises doubts about the clinical effectiveness of HDPM in autistic disorder.