Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Magnesium Hydroxide”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1985

Action of hydrochloric acid on aluminum hydroxide-magnesium hydroxide gels and magaldrate: 27Al NMR and pH-stat studies.

Neutralization of mixtures of aluminum hydroxide-magnesium hydroxide gels and of magaldrate by hydrochloric acid were studied by 27Al NMR under conditions of both equilibrium and kinetic control. Under conditions where equilibrium has been attained, an aluminum NMR signal is detectable for suspensions of the mixed gels and magaldrate only after enough acid has been added to exhaust the acid-neutralizing capacity of the magnesium hydroxide. Mixed gels seem to form several soluble aluminum-containing species as neutralization proceeds. Under the conditions of the modified Beekman neutralization procedure, in which the species concentrations reflect neutralization kinetics, mixed gels show a sharp burst of the hexaaquoaluminum cation as acid is added followed by a slow loss of that cation from solution and an accompanying slow rise in pH. Magaldrate shows a steady increase in the hexaaquoaluminum cation with added acid. Differences between magaldrate and mixed gels are also apparent in pH-stat titrations in which magaldrate displays a biphasic response, contrasting to the two burst phases with an intervening lag phase observed for mixed gels. The results of the 27Al NMR and pH-stat titrations are consistent with the hypotheses that magaldrate is a homogeneous substance with a hydrotalcite-like structure and that mixed gels consist of a magnesium hydroxide core surrounded by aluminum hydroxide.

Aluminum↗
PubMed1986

Action of hydrochloric acid on aluminum hydroxide-magnesium hydroxide gels and magaldrate: quasi-elastic light scattering studies.

The effects of hydrochloric acid on mixed gels of aluminum and magnesium hydroxide and on magaldrate have been examined using quasi-elastic light scattering. Particles of magaldrate and mixed gels behave differently. The magaldrate particles initially decrease in size in response to increasing amounts of hydrochloric acid up to that sufficient to neutralize all the magnesium hydroxide present, then increase in size to approximately 2 microns. The composition of the mixed gels appears to be particularly important in determining the reaction with limited amounts of acid. For these particles, which are thought to consist of a magnesium hydroxide core surrounded by an aluminum hydroxide sheath, slow erosion of the aluminum hydroxide was apparently followed by complete disintegration of the particles. Particles which remain grow in size to approximately 3 microns.

Aluminum Hydroxide↗
PubMed1977

The bio-availability of beta-acetyldigoxine alone and combined with aluminum hydroxide and magnesium hydroxide (Alucol).

The bio-availability of Novodigal (beta-acetyldigoxine) alone and applied together with Alucol (aluminum hydroxide, magnesium hydroxide) was studied in six healthy probands. Bio-availability parameters were calculated from the areas under the plasma concentration curves and from the comparison of the blood levels after absorption during steady state. There was no significant difference between the bio-availability of beta-acetyldigoxine alone and that of the combination with Alucol. Thus, beta-acetyldigoxine combined with antacids of the aluminum hydroxide and magnesium hydroxide type can be applied in the same dosage as usual since no decrease of effect has to be apprehended.

Adult↗
PubMed1986

Preparation, characterization, and controlled release from coprecipitates of fluorescein and magnesium hydroxide.

Magnesium hydroxide was precipitated as a lyophobic sol in the presence of various concentrations of fluorescein sodium (3'6'-dihydroxyspiro[isobenzofuran-1(3H),9'-[9H]xanthen++ +]-3-one, disodium salt) ranging in molar equivalents between 0.1 and 2 times that of the hydroxide. Coprecipitates were washed and dried, and release of the dye and magnesium was determined (pH 7.4, 37 degrees C) from rotating disks. Release rates varied depending upon fluorescein content. The rate of dye release was retarded by less than or equal to 10(4) times that of fluorescein sodium alone, implying the existence of some form of solid association between the components of the coprecipitates. The presence of the dye in certain concentrations reduced magnesium hydroxide dissolution rates by a factor of three. Fluorescein dissolution rates, when expressed as percent release, passed through a minimum (coincident with the dye-induced reduction in Mg(OH)2 dissolution). Adsorption experiments revealed evidence for multiaffinity binding of fluorescein at the surface of freshly precipitated Mg(OH)2. Magnesium, fluorescein, and water contents of the coprecipitates were characterized by atomic absorption and UV spectroscopy and by thermogravimetric analysis. Fluorescein content increased in direct proportion to its initial concentration in solution. Controlled, but variable release of this easily assayed dye is possible by employing precipitates with different fluorescein contents.

Adsorption↗
PubMed1990

Adverse effect of orally administered magnesium hydroxide on serum magnesium concentration and systemic acid-base balance in adult cattle.

Two cows, 1 with diarrhea and 1 with signs of forestomach outflow obstruction, were treated in part with repeated doses of a commercially available antacid/cathartic preparation containing magnesium hydroxide. Both cows subsequently were determined to have hypermagnesemia, along with severe metabolic alkalosis. In addition, each cow was comatose at the time of death. A clinical study was initiated to investigate the causal relationship between the ingestion of magnesium hydroxide and the generation of hypermagnesemia and metabolic alkalosis in adult cows. Twelve healthy mature cross bred beef cows were allotted at random to a fed or fasted (simulated anorexia) group, with 2 untreated and 4 treated cows in each group. A single dose of magnesium hydroxide (1.5 g/kg of body weight, suspended in 3.8 L of warm water) was administered per os to each treated cow, whereas each control cow was given only water. Individual determinations of selected venous blood gas values (plasma bicarbonate ion [HCO3-] concentration, and base excess [BE]), serum magnesium (Mg) concentration, and urine magnesium fractional clearance ratio (Mg-FCR) were made immediately before drug administration, and at 2, 4, 8, 12, 24, and 36 hours after treatment. Compared with control values at the conclusion of the study, mean serum Mg concentration, urine Mg-FCR, plasma HCO3- concentration, and BE were significantly higher (P = 0.0001, P = 0.0015, P = 0.028, and P = 0.021, respectively) in treated cows.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗
PubMed1986

Use of magnesium hydroxide and low magnesium dialysate does not permit reduction of aluminum hydroxide during continuous ambulatory peritoneal dialysis.

In an effort to reduce the ingestion of aluminum in phosphate-binding antacids, we treated seven patients on continuous ambulatory peritoneal dialysis (CAPD) with low magnesium dialysate and phosphate binders containing both aluminum and magnesium hydroxide. The total amount of phosphate binders prescribed was adjusted to maintain the serum phosphorus at normal levels. The dose of magnesium hydroxide was limited by intolerable gastrointestinal side effects in six of the seven patients. One patient also developed symptomatic hypermagnesemia. When magnesium hydroxide was prescribed in tolerable doses, the mean aluminum dose was not significantly decreased compared with the dose when taking aluminum hydroxide alone. We conclude that substitution of magnesium hydroxide for aluminum hydroxide as a phosphate binder fails to reduce the dose of aluminum in most patients on CAPD.

Adult↗
PubMed1991

Enhancement of absorption and effect of glipizide by magnesium hydroxide.

The effects of magnesium hydroxide on the pharmacokinetics and pharmacodynamics of glipizide were studied in eight healthy volunteers in a randomized crossover trial. After an overnight fast, 5 mg glipizide was given with either 150 ml water or water containing 850 mg magnesium hydroxide. Magnesium hydroxide increased the areas under the plasma glipizide concentration-time curves (AUC) from 0 to 1/2 hour and from 0 to 1 hour by 180% (p less than 0.05) and 69% (p less than 0.05), respectively. The peak plasma concentration, time to peak, total AUC, elimination half-life, and mean residence time of glipizide remained unchanged. The incremental plasma insulin area from 0 to 1/2 hour increased by 85% (p less than 0.05), and the time to maximal insulin response was reduced (p less than 0.05) during the magnesium hydroxide phase. The corresponding decremental plasma glucose area increased fourfold (p less than 0.05), and the maximal glucose decrease was 35% greater (p less than 0.05) than during the control phase. We conclude that the concomitant ingestion of magnesium hydroxide and glipizide may result in accelerated absorption of glipizide and increased early insulin and glucose responses.

Adult↗
PubMed1989

[Drug interactions during storage of mixtures of the antacid group. III. Effect of relative humidity on structural changes in mixtures aluminum hydroxide gel and magnesium hydroxide in the solid phase].

Mixtures of A1(OH)3 gel and Mg(OH)2 were stored for 14 months in the solid phase in chambers with relative air humidity of 35%, 55%, 76% and 92%. IR spectra of the stored mixtures were measured. In mixtures stored at relative air humidity of 35% there were found no changes in IR spectra, while the mixtures stored at relative air humidity of 92% proved to exhibit IR spectra characteristic for hydrotalcite.

Aluminum Hydroxide↗
PubMed1986

The effect of sodium bicarbonate versus aluminum-magnesium hydroxide on postprandial gastric acid in duodenal ulcer patients.

When ingested 1 hour after a meal, conventional liquid antacids have a buffering effect of approximately 2 hours, while in the fasting state their effect is brief, lasting less than 1 hour. We tested the hypothesis that equal doses of antacid, one water soluble (sodium bicarbonate) and the other water insoluble (aluminum hydroxide plus magnesium hydroxide, MaaloxR), would have similar durations of postprandial buffering if the water soluble antacid regenerates the particulate protein buffer of the meal that leaves the stomach more slowly than liquids. Tests were conducted in random order on three separate days in 10 patients with duodenal ulcer. The effects of 30 ml of 2.39 M sodium bicarbonate (6.17 g, about 1 teaspoonful), the aluminum-magnesium antacid, each equivalent to 71.7 mmol of in vitro buffer, and water as a control on pH, hydrogen ion activity, and titratable acidity were compared. Thirty milliliters of each was swallowed 1 and 3 hours after ingestion of a standard solid plus liquid. Compared to the water control each dose of sodium bicarbonate significantly increased intragastric pH and decreased hydrogen ion activity and titratable acidity for only 1 hour. Each dose of the aluminum-magnesium antacid significantly buffered intragastric contents for 2 hours. These findings indicate that sodium bicarbonate transiently buffers postprandial intragastric contents. Therefore, sodium bicarbonate fails to reconstitute the protein buffer of the meal effectively, and the observations suggest that it leaves the stomach rapidly with the liquid phase of the meal. However, the water insoluble, aluminum-magnesium antacid has a longer duration of buffering, probably because it leaves the stomach more slowly, largely with the solid portion of the meal.

Adult↗
PubMed1992

Effect of magnesium hydroxide on the absorption and efficacy of tolbutamide and chlorpropamide.

The effect of magnesium hydroxide on the absorption and efficacy of tolbutamide and chlorpropamide was examined in a total of 32 healthy volunteers in two separate, randomized parallel-group studies, with 16 subjects in each study. After an overnight fast, the first group of 8 volunteers ingested 500 mg tolbutamide or 250 mg chlorpropamide with 150 ml water, and the second group the same doses of the active drugs with 150 ml water containing 850 mg magnesium hydroxide. Magnesium hydroxide increased the area under the plasma tolbutamide concentration-time curve (AUC) from 0 to 1 h and from 0 to 2 h by 5-fold and 2.5-fold, respectively. The peak plasma concentration, peak time and total AUC were not significantly altered. The incremental insulin area and the decremental glucose area from 0 to 1.5 h were significantly larger in the magnesium hydroxide group than in the controls. The maximum insulin response to tolbutamide was increased fourfold by coadministration of magnesium hydroxide, and it occurred about 1 h earlier than in the control group. In addition, the maximum fall in plasma glucose concentration was attained about 1 h earlier in the antacid group. A tendency to an increased rate of chlorpropamide absorption was observed after magnesium hydroxide, but it did not appear to affect the insulin and glucose responses to chlorpropamide. It is concluded that magnesium hydroxide increased the early bioavailability of tolbutamide, resulting in enhanced insulin and glucose responses. A tendency toward accelerated chlorpropamide absorption by magnesium hydroxide was also observed, but the efficacy of chlorpropamide was unaffected.

Adult↗
PubMed1988

Chlorthalidone reduces calcium oxalate calculous recurrence but magnesium hydroxide does not.

We examined the effectiveness of chlorthalidone or magnesium hydroxide in the prevention of recurrent calcium oxalate kidney calculi. In a double-blind random allocation design daily dosages of 25 or 50 mg. chlorthalidone, 650 or 1,300 mg. magnesium hydroxide, or an identical placebo were administered. All groups showed significantly decreased calculous events compared to the pretreatment rates. During the trial 56.1 per cent fewer calculi than predicted developed in the placebo group (p less than 0.01), whereas the groups receiving low and high dosage magnesium hydroxide showed 73.9 and 62.3 per cent fewer calculi, respectively (p less than 0.001 and less than 0.01, respectively). Chlorthalidone treatment resulted in a 90.1 per cent decrease from predicted rates and both dosages yielded similar results. When the treatments were compared chlorthalidone was significantly better than the placebo or magnesium hydroxide (p less than 0.01). The large decreases in calculous events seen when placebo or ineffective therapy was given underscore the positive treatment bias that occurs when historical controls are used and they demonstrate the need for proper experimental design.

Calcium Oxalate↗
PubMed1988

Oral administration of magnesium hydroxide to subjects with insulin-dependent diabetes mellitus: effects on magnesium and potassium levels and on insulin requirements.

Intra- and extracellular levels of magnesium and potassium were determined in 16 subjects with insulin-dependent type I diabetes mellitus (IDDM) and 30 healthy controls. Subjects with IDDM had lower levels of magnesium in muscle biopsies (p less than 0.001), plasma (p less than 0.001), and mononuclear cells (p less than 0.05), and higher urinary excretions of magnesium (p less than 0.01), and lower levels of potassium in muscle biopsies (p less than 0.001), and erythrocytes (p less than 0.05), as compared with those in controls. Magnesium hydroxide (500 mg/day) was administered orally to the diabetics. The levels of magnesium and potassium in muscle biopsies increased (p less than 0.001; p less than 0.001), while the plasma levels of magnesium and the urinary excretions of magnesium increased only temporarily, during 21 weeks of treatment. The requirements of insulin were reduced (p less than 0.001) during the course of the study, whereas the levels of glycosylated hemoglobin (HbA1c) and glucose were not changed. The findings indicate that administration of magnesium hydroxide is useful to treat muscular magnesium and potassium deficiency in diabetics.

Adult↗
PubMed1991

The effects of magnesium hydroxide on the absorption and efficacy of two glibenclamide preparations.

1. The effect of magnesium hydroxide on the absorption and efficacy of two glibenclamide preparations was investigated in healthy volunteers in two separate studies, using a randomized cross-over design with two phases. 2. A single dose of magnesium hydroxide (850 mg) or water only (150 ml) was given immediately after the ingestion of a micronised (1.75 mg, seven subjects) or a non-micronised (2.5 mg, six subjects) preparation of glibenclamide. Plasma concentrations of glibenclamide, insulin and glucose were measured. 3. Magnesium hydroxide accelerated (P less than 0.05) the absorption of glibenclamide from the micronised preparation to a small extent but the extent of absorption and the insulin and glucose responses were unaltered. 4. Coadministration of magnesium hydroxide with the non-micronised glibenclamide preparation increased the area under the plasma glibenclamide concentration-time curve from 0 to 3 h, five-fold (P less than 0.05), the total area three-fold (P less than 0.05) and the peak drug concentration three-fold (P less than 0.05). The incremental insulin area from 0 to 3 h was increased 35-fold (P less than 0.05) and the maximum insulin response 10-fold (P less than 0.05) by magnesium hydroxide. 5. Concomitant ingestion of magnesium hydroxide and non-micronised glibenclamide may greatly enhance the absorption and efficacy of glibenclamide. The absorption of micronised glibenclamide appears to be only slightly influenced by magnesium hydroxide.

Adult↗
PubMed1991

The effect of magnesium hydroxide on the oral absorption of ibuprofen, ketoprofen and diclofenac.

1. The effect of magnesium hydroxide on the oral absorption of ibuprofen, ketoprofen and diclofenac was investigated in two randomized cross-over studies, both consisting of two phases. 2. Single doses of magnesium hydroxide (850 mg) or of water (150 ml) only were given to six healthy volunteers immediately after the ingestion of ibuprofen (400 mg, Study 1), ketoprofen (50 mg, Study 2) or diclofenac (50 mg, Study 2). Plasma drug concentrations were measured up to 24 h. 3. Magnesium hydroxide increased the area under the plasma ibuprofen concentration-time curve between 0 and 1 h by 65% (P less than 0.05) and the peak concentration of ibuprofen in plasma by 31% (P less than 0.01). The time to peak was shortened by about 0.5 h. The extent of bioavailability of ibuprofen was not increased by magnesium hydroxide. 4. Neither the rate nor the extent of absorption of ketoprofen or diclofenac was changed significantly by magnesium hydroxide. 5. When rapid onset of the analgesic effect of ibuprofen is required, concomitant ingestion of an antacid, which contains magnesium hydroxide without aluminium, is recommended.

Adult↗
PubMed1979

Effect of interaction of aluminum hydroxycarbonate gel and magnesium hydroxide gel on acid neutralization.

Acid neutralization by mixtures of aluminum hydroxycarbonate gel and magnesium hydroxide gel differs from the sum of the acid neutralization of each gel. Acid neutralization by magnesium hydroxide gel in the mixture is not observed until after a substantial portion of the aluminum hydroxycarbonate gel has reacted with acid, even though magnesium hydroxide gel is the faster reacting of the two gels. It is hypothesized that amorphous aluminum hydroxycarbonate forms a coating on the crystalline magnesium hydroxide particles due to electrostatic attraction. This coating prevents protons from reaching the highly reactive magnesium hydroxide until the coating is dissolved by the acid neutralization of aluminum hydroxycarbonate.

Acids↗
PubMed1989

Inhibitory effect of magnesium hydroxide on methylazoxymethanol acetate-induced large bowel carcinogenesis in male F344 rats.

The effect of dietary magnesium hydroxide on colon carcinogenesis induced by methylazoxymethanol (MAM) acetate was examined in male F344 rats. MAM acetate was administered by i.p. injection to rats at 25 mg/kg body wt once per week for 3 weeks. Starting 2 weeks after the final MAM acetate exposure, the diet containing 500 or 1000 p.p.m. magnesium hydroxide was fed for 227 days. In the groups receiving magnesium hydroxide and MAM acetate, the incidence of colon neoplasms was decreased when compared with that in the group given MAM acetate alone. The inhibitory effect of dietary magnesium hydroxide on MAM acetate-induced colon carcinogenesis was greater at the lower dose than that at the higher dose of magnesium hydroxide in the diet. Neoplasms in other organs were rare and were not affected by the dietary magnesium hydroxide.

Animals↗