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Results for “MAGNESIUM OXIDE”

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PubMed1996

[Role of mass transfer processes in drug formulation].

Authors call attention on the possibilities that drug release from solid preparations can be influenced by solubility and dissolution rate according to the clinical requirements regarding the duration of action. The therapeutic time interval may be modulated influencing the rate of absorption by controlling dissolution rate and changing the transport through the membranes. The results obtained from dissolution, absorption and efficacy studies of the evaluated active substances (magnesium oxide, metoprolol, nitrofurantoin) demonstrate the significance of mass transfer processes in the drug formulation.

Dosage Forms↗

PubMed2000

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.

Administration, Oral↗

PubMed2003

[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.

Calcium Compounds↗

PubMedDate not supplied

Direct-response ultraviolet thermoluminescent dosimeter.

An integrating solid-state dosimeter has been developed to detect ultraviolet radiation using the process of "direct" ultraviolet stimulation. This process yields a thermoluminescent signal after an exposure to ultraviolet radiation, without prior exposure to ionizing radiation. Magnesium oxide crystals were found to show a directly stimulated thermoluminescent glow peak at 145 degrees C which can be utilized as a linear, energy-independent ultraviolet dosimeter.

Magnesium Oxide↗

PubMed1987

Urinary mucoprotein in pediatric urolithiasis.

Primary bladder stone is a common pediatric surgical problem in developing countries. Many theories are prevalent. The stone matrix theory is based on increased excretion of its precursor, the uromucoid (the urinary mucoprotein). Uromucoid, studied in urine and stones by the electroimmunodiffusion technique in 49 cases with controls, showed significantly increased excretion in stone cases. Family income and serum protein were the only important influencing factors (negative). Causal relationship between uromucoid excretion, stone matrix, and pediatric bladder stones is discussed. Methylene blue decreased uromucoid excretion but not magnesium oxide, vitamin C or B6 (four common therapeutic drugs for prevention/dissolution of urolithiasis).

Ascorbic Acid↗

PubMed1978

Interference by tannic acid with the effectiveness of activated charcoal in "universal antidote".

Evidence is presented to show that tannic acid is responsible for the reduced effectiveness of "universal antidote" as compared with activated charcoal alone. Adsorption isotherm data indicate that tannic acid binds strongly to charcoal and hence uses up part of the adsorption capacity that would otherwise be available for binding of a drug or poison. Data on sodium salicylate adsorption from simulated gastric fluid, both with and without the presence of tannic acid, are presented that illustrate clearly that tannic acid interferes significantly with the adsorption of salicylate. Magnesium oxide, another component of "universal antidote," was found to offer no interference to salicylate adsorption, presumably because it does not adsorb to charcoal to any significant extent.

Adsorption↗

PubMed2000

Fatal hypermagnesemia in a child treated with megavitamin/megamineral therapy.

We report a case of fatal hypermagnesemia resulting from the unsupervised use of high doses of magnesium oxide administered as part of a regimen of megavitamin and megamineral therapy to a child with mental retardation, spastic quadriplegia, and seizures. The treatment regimen was given at the recommendation of a dietician working as a private nutritional consultant without the involvement or notification of the child's pediatrician. Hypermagnesemia is an uncommon but serious side effect of the use of magnesium containing compounds. These compounds are widely used as laxatives and dietary supplements, and serious side effects are uncommon when used in appropriate dosages and with adequate supervision. The use of alternative medical therapies, including megavitamin/megamineral therapy, is widespread. Many patients use alternative medicine or seek care from alternative medicine practitioners without the recommendation or knowledge of their primary physicians. Despite unproved benefit, many alternative therapies may be safe. However, unsupervised use of generally safe treatments can result in serious side effects. This case report serves to illustrate the characteristic pathophysiologic changes of severe hypermagnesemia, an entity rarely seen in pediatric practice, and more importantly, it alerts primary care and subspecialty pediatricians to be aware of and monitor the use of alternative medical therapies in their patients.

Complementary Therapies↗

PubMedDate not supplied

[Studying the anti-ulcer activity of gastrobiol].

Gastrobiol--a new preparation comprising a mixture of lyophilized sea-buckthorn oil, vitamin U, and magnesium oxide, produces a pronounced antiulcerous action on the mucous membrane of the stomach and duodenum. The regenerative effect of gastrobiol is more pronounced than that of pure sea-buckthorn oil and methyluracil.

Animals↗

PubMed1987

Computerized laser Doppler interferometric scanning of the vibrating tympanic membrane.

The vibrational movements of the tympanic membrane (TM) of in vitro human specimens were studied by computerized laser Doppler interferometry. The versatility of the method for measuring the velocity of the vibrating TM was demonstrated by point measurements, horizontal sweeps, and three-dimensional scans of the entire TM. Single phases of the TM vibration were examined and plotted three-dimensionally. All information was stored digitally, making it possible to recreate the movements as in slow motion on the oscilloscope. The effect of coating the TM with a thin layer of magnesium oxide was studied. The repeatability of the method was demonstrated. TM vibrational patterns at different sound pressure levels and frequencies are displayed and discussed as also are the results of scanning the specimen in different positions.

Computers↗

PubMed2006

Cusums to measure chronic daily headache.

OBJECTIVE: To investigate whether cumulated summed differences (cusums) can be used as a method for detecting effective interventions in chronic daily headache (CDH). If so, then can such interventions be detected sooner than 28 days? BACKGROUND: CDH probably represents the greatest current challenge in the field of headache treatment. Clinical trial methodologies for its study are not standardized but usually use fixed 28-day observation periods. Similarly, 28-day observation periods are common review intervals for stepped-care patient management strategies. METHODS: A theoretical patient was modeled, with daily headache scores that had maximal variation for 28 consecutive daily measures. The cusums for this "norm" or control data set were plotted and correlated with time using a simple spreadsheet. Departure of a postintervention cusum from the 95% confidence interval of the control data set was chosen as an indicator of sensitivity to various model perturbations that had clinical correlates. RESULTS: When 1 to 17 randomly distributed headache-free days were used to perturb the 28-day model, cusums consistently diverged from the norm. If at least 3 headache-free days occurred, then the cusum detected the intervention in less than 28 days of observation. Reanalysis of a previously published study of magnesium oxide suggests that its negative conclusions should be reconsidered. CONCLUSION: Cusums can be useful tools for detecting change in CDH, whether at the level of the clinical trial or when managing patients using stepped-care treatment algorithms.

Clinical Trials as Topic↗

PubMed1996

Small bowel obstruction caused by a medication bezoar: report of a case.

We report herein the rare case of a 26-year-old woman who developed a small-bowel obstruction caused by a medication "bezoar" or enterolith, following the long-term ingestion of magnesium oxide cathartics for constipation. Medication bezoars resulting from laxatives or cathartics have rarely been reported and we were only able to find two other such cases in the literature.

Abdomen, Acute↗

PubMed1999

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.

Aged↗

PubMed2000

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.

Administration, Oral↗

PubMed1991

[Magnesium poisoning in an infant].

We present the case of a girl aged 3 weeks with extreme hypermagnesaemia (7.94 mmol/l) due to an overdose of magnesium oxide, prescribed as a laxative. We treated her successfully with a combination of hyperhydration, forced diuresis and natriuresis, and additional intravenous calcium and insulin. We also performed an exchange transfusion which, however, had a questionable effect on the final outcome.

Combined Modality Therapy↗

PubMed2003

[Simultaneous photometric determination of covalently bound fluorine and fluoride ion contamination adsorbed on drugs in the low ppm range after alkaline pulping].

The simultaneous determination of fluorine resulting from inorganic fluoride as well as fluorine-containing solvents adsorbed to drugs was achieved in the 0.1-30 ppm range by a combination of decomposition with magnesium oxide at 800 degrees C and steam distillation of the resulting fluoride followed by photometric measurement of the aminomethylalizarindiacetic acid-cerium(III) complex at 620 nm. The inevitable loss of fluoride occurring during the decomposition and distillation processes was corrected using factors derived from authorized calibrations. The method was validated using glucose contaminated with dexamethasone which contains 4.84% fluorine per molecule.

Alkalies↗

PubMed1997

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.

Adolescent↗

PubMed1988

Spectral processing for parallel recording of elemental maps.

Seven different one-, two-, or three-parameter analytic expressions were tested for their applicability to electron energy-loss spectral processing for mapping of atomic distributions in images of magnesium oxide crystals. Two-point two-parameter fits all provided indistinguishable results. Fine structure in the spectrum produced major quantitative inconsistencies for any given expression. This effect was exacerbated with the use of three-parameter expressions. Mass-thickness effects on the oxygen map of Mg0 were inconsequential up to a crystal thickness of 30 nm, but became dominant and unacceptable at a 50% increase in thickness above this. This observation can be explained by a specific single inelastic scatter coupled with any number of elastic scattering events.

Crystallization↗

PubMed2002

[Investigation of actual use of laxatives and application to the active drug information offer in drug control guidance].

On the therapy of constipation, there are few reports that surveyed the actual circumstance of patients taking laxatives and the effectiveness of the drug. In this study, we investigated the contents in prescription, the actual conditions of administration of laxatives, and the subjective symptoms of inpatients in all wards of Kanazawa University hospital (2000. 12.1-2000. 12. 10). As a result of the investigation, the percentage of patients prescribed some laxatives was found to be about 31.5% (274) of all hospitalized patients (871), and among them about 16% (43) of the patients had some problems in defecation control. One of the causes leading to the problems for some patients (11) among them seemed to be due to the lesser amount of magnesium oxide taken per day. Then, in the ophthalmology ward we further investigated the proper use of laxatives and the defecation condition of the patient using a questionnaire paper and a record paper (20 cases). Patients became constipated by hospitalization, and although being administered some laxatives, they were often insufficient to control the defecation. Some patients (7) with changeable defecation control could be improved by change or addition of prescription. Pharmacist concerned 5 cases of patients with change or addition of prescription. This study indicates that pharmacists should actively offer information and rational usage of laxatives to doctors and patients.

Cathartics↗