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At least 19 recordsLinked to original sources
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↗
PubMed1991

[Magnesium hydroxide and aluminum hydroxide in the treatment of gastroesophageal reflux].

Fifteen children with gastro-esophageal reflux took part in a treatment trial with a regimen of magnesium hydroxide and aluminium hydroxide for 8 weeks period (700 mmol/1.73 mq/die). All children were evaluated clinically and underwent a 24-hour continuous esophageal pH-monitoring both at diagnosis and after 8 weeks of treatment. After therapy 12/15 children were cured and 3/15 improved. Moreover the total percentage of time during which pH was less than 4, the number of reflux episodes and the number of refluxes lasting than 5' recorded during 24-hour continuous esophageal pH-monitoring were significantly reduced after treatment. The Authors conclude that antacids in large quantities are effective in medical treatment of gastro-esophageal reflux.

Aluminum Hydroxide↗
PubMed1975

[Dynamic comparative study of the intraalveolar cell population after intratracheal injection of beryllium hydroxide and aluminum hydroxide in the rat].

A sequential quantitative analysis of free alveolar cells was performed on S.P.F. rats after intratracheal injection of Be (OH)2 and Al (OH)3. The induced lesions were entirely restored 20 days after the initial injection. Beryllium hydroxide inhibited DNA synthesis in the free alveolar macrophages and the transeptal cellular flow could be evidenced. Aluminium hydroxide increased the number of free cells without inhibiting DNA synthesis. Quantitative variations of polymorphonuclears, lymphocytes and macrophages were correlated with changes in the alveolar environment. A strong direct correlation between the number of lymphocytes and DNA synthetizing macrophages was shown out. This reaction was not observed in beryllium treated rats.

Aluminum↗
PubMed1990

Insights into the function of the zinc hydroxide-Thr199-Glu106 hydrogen bonding network in carbonic anhydrases.

The exact functional role of the zinc hydroxide (water)-Thr199-Glu106 hydrogen bond network in the carbonic anhydrases is unknown. However, from the results of molecular dynamics simulations (MD) we are able to better define its function. From computer graphics analysis and MD simulations on the zinc hydroxide form of human carbonic anhydrase II we find that this interaction forces the hydroxide hydrogen atom to be in a "down" position relative to the deep water-binding pocket. From previous work we have found that this pocket is a high-affinity binding site for CO2. We also note that during the timescale of our simulation (126 ps) the hydrogen bonds between the hydroxide hydrogen atom and Thr199 and the one between Thr199 and Glu106 are not fluxional. We propose that the role of the zinc hydroxide (water)-Thr199-Glu106 hydrogen bond network is to lock the hydrogen atom in the down position in order to expose the CO2 molecule bound in the deep water pocket to a lone pair of the hydroxide oxygen atom. This would allow for the rapid reaction of the CO2 molecule around the zinc ion. Furthermore, if the hydroxide hydrogen atom were not locked in the down position the binding of CO2 to the deep water pocket could be interfered with by the unrestrained hydroxide hydrogen atom (e.g. the N-Zn-O-H torsion could undergo rotational transitions that would partially block the deep water pocket). In summary, the roles we ascribe to this hydrogen bonding network are (1) to allow for facile access of CO2 to the deep water pocket and (2) to allow for maximal exposure of a hydroxide oxygen lone pair to the CO2 carbon atom.

Binding Sites↗
PubMed1991

Advantage of early initiation of aluminum hydroxide administration for the prevention of experimental progressive renal disease.

Aluminium hydroxide, a phosphate binder, is regarded as a strong candidate to halt the progression of chronic renal disease. In order to determine the most effective time to start treatment, aluminium hydroxide was administered either immediately (ADR-0w), or at 8 weeks (ADR-8w) or 16 weeks (ADR-16w) after repeated injection of Adriamycin (ADR) inducing glomerular sclerosis. In the aluminium hydroxide-untreated group the survival rate at the end of the experiment was 50%, while the early initiation of aluminium hydroxide (ADR-0w) resulted in a greater survival rate of 90%. Serum phosphate concentration and serum calcium-phosphate product were significantly less in the aluminium hydroxide groups (ADR-0w, 8w, 16w) than in the untreated group after week 20. Urinary protein excretion was significantly less in the ADR-0w and ADR-8w groups at week 12 or 16 compared to the aluminium hydroxide-untreated group. Blood urea nitrogen in the aluminium hydroxide groups was significantly less than that in the untreated group at week 34. Histological examination revealed that glomerular sclerosis was less severe in the ADR-0w and ADR-8w groups than in the aluminium hydroxide-untreated group, and glomerular hypertrophy was significantly decreased in the ADR-0w group. We conclude that early treatment with aluminium hydroxide was effective in preventing renal deterioration in focal glomerular sclerosis induced by Adriamycin.

Aluminum Hydroxide↗
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↗
PubMed1991

The solvent effects of calcium hydroxide irrigating solution on bovine pulp tissue.

The solvent effects of calcium hydroxide irrigating solution (used alone and in combination with sodium hypochlorite) on bovine pulp tissue were studied. Forty pieces of pulp tissue weighing 90 mg each were treated with calcium hydroxide solution alone, calcium hydroxide and sodium hypochlorite alternated, sodium hypochlorite alone, and saline alone. Each piece of tissue was treated for 32 min. Desiccated pretreatment and posttreatment weights were compared. There was no significant difference between the dissolution capability of calcium hydroxide solution used alone and of saline. No significant difference was noted between calcium hydroxide solution and sodium hypochlorite used alternately, and sodium hypochlorite used alone. However, both of these groups were significantly more effective at dissolving tissue than calcium hydroxide solution alone or saline. Calcium hydroxide solution was an ineffective solvent of pulpal tissue. If tissue dissolution is desired during root canal therapy, the use of calcium hydroxide solution as the sole irrigant is no more effective than saline.

Analysis of Variance↗
PubMed1991

Calcium citrate markedly enhances aluminum absorption from aluminum hydroxide.

The effect of calcium citrate on intestinal aluminum absorption, assessed by the increment in urinary aluminum excretion, was evaluated in eight normal men. Baseline urinary aluminum excretion was determined for 2 days; thereafter, subjects ingested aluminum hydroxide for 3 days. In a cross-over study, subjects were given either calcium citrate, 950 mg four times a day, or placebo during the 3 days of aluminum hydroxide ingestion (2.4 g/d). Plasma aluminum levels were measured on the second control day and the third day of aluminum hydroxide ingestion. Baseline urinary aluminum excretion was 0.02 +/- 0.004 (6.5 +/- 1.1 micrograms/g creatinine) and 0.03 +/- 0.005 mumol/mmol creatinine (7.4 +/- 1.3 micrograms/g creatinine). These values increased during aluminum hydroxide therapy, but values were much greater when calcium citrate was ingested with aluminum hydroxide. On 3 consecutive days, urinary aluminum excretion levels were 11.1 +/- 3.23, 8.8 +/- 2.9, and 5.3 +/- 0.7 times greater during the administration of calcium citrate with aluminum hydroxide than with aluminum hydroxide alone. Plasma aluminum levels did not differ in the two treatment groups. Thus, calcium citrate markedly enhances the absorption of aluminum from aluminum hydroxide and the two must not be prescribed together in patients with renal failure.

Adult↗
PubMed1977

Relationship between zero point of charge and solubility product for hydroxides of polyvalent cations.

The zero point of charge (ZPC) of slightly soluble compounds is the pH at which their particles suspended in water have zero charge. The ZPC values of slightly soluble hydroxides were compared with their solubility product in the form of its negative logarithm, pKSP, and with th pH of their suspensions in pure water, pHSP, which is a function of pKSP. The ZPC-pKSP relation was nonlinear while the ZPC-pHSP relation was linear. Either equation can used to estimate the ZPC value of a hydroxide from its solubility product. The ZPC of a given hydroxide was higher than its pHSP because polyvalent cations are more extensively adsorbed and less extensively desorbed from the particle surface than the monovalent hydroxide ion. At the pHSP, there are equivalent amounts of the cation and of the hydroxide anion in solution, but the surface layer of the hydroxide particle contains an excess cation on an equivalent basis. This imbalance confers a positive charge to the particle. The solubility product of aluminum hydroxide, redetermined at 25 degrees by means of pH measurements, was 8 X 10(-33). Its ZPC, redetermined by microelectrophoresis, was 8.5 +/- 0.1.

Chemical Phenomena↗
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

Aluminum accumulation during treatment with aluminum hydroxide and dialysis in children and young adults with chronic renal disease.

BACKGROUND: The control of hyperphosphatemia is a major clinical problem in patients with chronic renal failure receiving regular dialysis treatment. Despite continuing concern about aluminum toxicity, aluminum-containing antacids are still used in many of these patients as phosphate-binding agents. Although maximal acceptable doses of aluminum hydroxide have been recommended, the safety and efficacy of these guidelines have not been evaluated. METHODS: Seventeen children and young adults (mean [+/- SD] age, 14.1 +/- 3.7 years) undergoing regular peritoneal dialysis were randomly assigned to treatment with either aluminum hydroxide (n = 7; maximal dose, 30 mg per kilogram of body weight per day) or calcium carbonate (n = 10; dose range, 2.5 to 12 g per day, according to serum phosphorus levels). Aluminum retention was assessed by serial measurements of plasma aluminum, deferoxamine-infusion tests, and measurements of bone aluminum content during a mean (+/- SD) follow-up of 13 +/- 2 months. The evolution of bone disease was also evaluated. RESULTS: Plasma aluminum levels and the increment in plasma aluminum after infusion of deferoxamine increased from base-line values in the patients treated with aluminum hydroxide, and aluminum-related bone disease developed in one patient. Serum phosphorus levels remained higher and serum calcium levels lower in the patients receiving aluminum hydroxide than in those receiving calcium carbonate. The skeletal lesions of secondary hyperparathyroidism improved in 7 of 10 patients receiving calcium carbonate but persisted or progressed in 6 of 7 patients given aluminum hydroxide (P less than 0.025). CONCLUSIONS: Aluminum hydroxide is less effective than calcium carbonate as a phosphate-binding agent for the control of hyperphosphatemia and is associated with aluminum retention in children and young adults with chronic renal failure who are receiving dialysis therapy.

Adolescent↗
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↗
PubMed1977

Aluminium hydroxide in bile-salt diarrhoea.

The treatment of choleraic diarrhoea remains a problem. Cholestyramine is effective but long-term treatment is often impracticable. In-vitro studies have shown that aluminium hydroxide has bile-acid-binding properties comparable with those of cholestyramine. The bile-acid-binding properties of aluminium hydroxide have now been investigated in vivo and applied to the treatment of patients with choleraic diarrhoea. Aluminium hydroxide increased the faecal bile-salt concentration of patients with a normal bowel habit whereas magnesium hydroxide had no effect. Eight patients with severe choleraic diarrhoea were treated with aluminium-hydroxide suspension: bowel motion became less frequent and daily faecal weight fell.

Adult↗