Aluminium bioavailability

The oral aluminium bioavailability of a representative food containing food additive acidic sodium aluminium phosphate (SALP), a leavening agent in baked goods, has been studied by accelerator mass spectrometry. In the experiments, rats were fed a special diet (biscuit containing 1 % or 2% acidic SALP, synthesized to contain A1). A1, which was used as a biological tracer, can be ultrasensitively analyzed by AMS. The rats received concurrent Al infusion for comparison with oral ingestion. ... 

BETA-BLOCKERS ANTACIDS CONTAINING MAGNESIUM AND ALUMINIUM t bioavailability of metoprolol and 1 bioavailability of atenolol, which may produce mild variation in the response to metoprolol and atenolol Variations in absorption of the respective beta-blockers Clinical significance may be minimal but be aware monitor BP at least weekly until stable when initiating antacid therapy. Warn patients to report symptoms of hypotension (light-headedness, dizziness on standing, etc.)... 

Owen, L.M.W., Crews, H.M. and Massey, R.C., Aluminium in tea SEC-ICP-MS speciation studies of infusions and simulated gastro-intestinal digests. Chem. Spec. Bioavail., 4(3) (1992) 89-96. 

Chelation of ciprofloxacin (V) by aluminium hydroxide and calcium carbonate reduces bioavailability, as seen in Fig. 10.11. Other quinolones (VI-IX), undoubtedly suffer the same fate. 

Fiaten TP (2002) Aluminium in tea - concentrations, speciation and bioavailability. Coord Chem Rev 228 385-395. 

As with many elements, total aluminium determinations are of limited value for environmental toxicological purposes, owing to the different toxicology/ bioavailability patterns related to the various A1 species, which justifies A1 speciation measurements. 

Sequential extraction or chemical fractionation techniques have been widely used in the characterization of various phosphorus fractions in soils and sediments, with an emphasis on the more bioavailable or plant-available inorganic forms (Condron et al., 2005). Early extraction procedures (Chang and Jackson, 1957 Williams et al., 1976b) focused on inorganic phosphorus associated with iron, aluminium and calcium, using various acid, base or salt extraction steps. Organic phosphorus was considered to be the residual or refractory phosphorus-containing fraction that remained after all other extractions had been performed. 

Shang, C., Caldwell, D.E., Stewart, j.W.B., Tiessen, H. and Huang, P.M. (1996) Bioavailability of organic and inorganic phosphates adsorbed on short-range ordered aluminium precipitate. Microbial Ecology 31,2 9-3 9. 

Beyer J., Aas E., Borgenvik H. K., and Ravn R, Bioavailability of PAH in effluent water from an aluminium works evaluated by transplant caging and biliary fluorescence measurements of Atlantic cod (Gadus morhua). Mar. Environ. Res., 46(1-5), 233-236,... 

An aluminium/magnesium hydroxide antacid reduced the bioavailability of captopril by 40%, but this did not seem to be clinically important The bioavailability of fosinopril was reduced by about one-third by Mylanta. An antacid did not affect ramipril pharmacokinetics. 

Another study found that Mylanta [aluminium/magnesium hydroxide and simeticone ] reduced the bioavailability of fosinopril 20 mg by about one-third. ... 

The manufacturers say that antacids (unspecified) do not affect the pharmacokinetics of etoricoxib to a clinically relevant extent Aluminium/magnesium hydroxides had no clinicaify significant effect on the bioavailability of celecoxib, or lumiracoxib. ... 

About 10 mL of a 5.8% suspension of aluminium hydroxide had no effect on the bioavailability of a single 50-mg dose of diclofenac i n 7 healthy subjeets. In another study, 10 mL of magnesium hydroxide suspension (850 mg) was found to have no signifieant effect on the rate or extent of absorption of a single 50-mg dose of dielofenac in 6 healthy, fasted sub-jeets. However, there was a tendeney to an increased rate of absorption. Aluco Gel (aluminium/magnesium hydroxide) had no effect on the extent of absorption of enterie-eoated dielofenac, but may have reduced the rate of absorption. No partieular preeautions would seem to be needed if these antaeids are given with dielofenae. 

Sodium bicarbonate increased the rate of naproxen absorption, and aluminium hydroxide and magnesium oxide decreased it. Dimeticone did not affect ketoprofen bioavailability. 

Ismail FA, Khalafallah N, Khalil SA. Adsorption ofketoirofen and bum adizone calcium on aluminium-containii antacids and its effect on ketoi ofen bioavailability in man. IntJPharmaceutics ( 9Z7) 34, 189-96. 

A multiple-dose study in 20 healthy subjects found that A/y/an/a (aluminium/magnesium hydroxide) aaAAmphojel (aluminium hydroxide) did not significantly affect the bioavailability of piroxicam 20 mg daily taken after food. Concurrent use need not be avoided. 

The bioavailability of tenoxicam 20 mg was found to be unaffected in 12 healthy subjects by aluminium hydroxide (Amphojel) or aluminium/magnesium hydroxide Mylanta) whether taken before, with, or after the tenoxicam, and in the fasted state or with food. No special precautions seem necessary. 

A study in 12 healthy subjects found thatMylanta (aluminium/magnesium hydroxide) 20 mL did not significantly affect the bioavailability of a single 200-mg dose of posaconazole, either when taken with food or when fasting. ... 

There is some inconclusive evidence that aluminium phosphate may possibiy cause a small reduction in the absorption of procainamide. Kaoiin-pectin appears to reduce the bioavailability of procainamide. 

No clinically significant interactions appear to occur between an aluminium/magnesium hydroxide antacid and cefaclor AF, ce-falexin, cefetamet pivoxil, cefixime or cefprozil between Alka-Seltzer and cefixime or between ceftibuten and Mylanta. In contrast, antacids reduce the bioavailability of cefpodoxime proxetil. 

A study in 10 healthy subjects found that 10 mL of an aluminium/magnesium hydroxide antacid (Maalox) reduced the bioavailability of cefpodoxime proxetil by about 40%. This was considered to be due to reduced dissolution at increased gastric pH values. These results confirm the findings of a previous study with sodium bicarbonate and aluminium hydroxide. It has been recommended that cefpodoxime is given at least 2 hours after antacids. ... 

An aluminium/magnesium hydroxide antacid (Maalox) does not affect the bioavailability of cefprozil. ... 

A study in 12 healthy subjects found that the bioavailability of a single 500-mg dose of cycloserine was not affected by 15 mL oiMylanta (aluminium hydroxide 400 mg, magnesium hydroxide 400 mg, simeticone 40 mg per 5 mL). Mylanta was given 9 hours before the eyeloserine, at the same time as the cycloserine, immediately after meals, and at bedtime on the dosing day and following day. ... 

Didanosine chewable tablets contain antacids (aluminium/magnesium hydroxide) in the formulation, but it has been shown that they do not affect the bioavailability of isoniazid. ... 

Aluminium/magnesiium hydroxide and aluminium hydroxide do not significantly affect the bioavailability of amoxicillin or amoxicillin with clavulanic acid (co-amoxiclav). Antacids may reduce the absorption of the hydrochloride salt of pivampicillin. 

Deppermam K-M, Lode H, Hoffken G, Tschink G, Kalz C, Koeppe P. Influence of ranitidine, pirenzepine, and aluminium m nesium hydroxide on die bioavailability of various antibacterials, includii amoxicillin, cep exin, dojq cycline, and amoxicillin-clavulanic acid. Antimi-crob Agents Chemother 9Z9)3> i, 1901-7. 

It is believed that eertain of the quinolone functional groups (3-carboxyl and 4-oxo) form insoluble chelates with aluminium and magnesium ions within the gut, which reduces their absorption. " The stability of the chelate formed seems to be an important factor in determining the degree of interaction. It has been suggested from animal studies that adsorption of quinolones by aluminium hydroxide re-precipitated in the small intestine may be a factor in the reduced bioavailability of quinolones. See also Quinolones + Iron or Zinc compounds , p.336. 

Table 10.3 , (p.329) shows that the aluminium/magnesium antacids can greatly reduce the bioavailabilities of the quinolones. Separating their administration to reduce the admixture of the two drugs in the gut minimises the interaction, a very broad rule-of-thumb being that the quinolones should be taken at least 2 hours before and not less than 4 to 6 hours after the antacid.The only obvious exception is fleroxacin, which appears to interact minimally. 

Information about the interactions with calcium carbonate is more limited than with the aluminium/magnesium antacids, but Table 10.3 , (p.329) shows that the bioavailabilities of ciprofloxacin and norfloxacin, and to a lesser extent gemifloxacin, can be reduced. These reductions are less than those seen with the aluminium/magnesium antacids, but using ciprofloxacin as a guide a very broad rule-of-thumb would be to separate the drug administration by about 2 hours to minimise this interaction. This is clearly not necessary with levofloxacin, lomefloxacin, moxifloxacin or ofloxacin, nor probably with some of the other qui-... 

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