Antacids interactions

D Arcy PF and McElnay JC. Drug-antacid interactions Assessment of clinical importance. Drug In tell Clin Pharm 1987 21 607-17. 

Tetracyclines and Metals. Tetracyclines can combine with metal ions, such as calcium, magnesium, aluminum, and iron, in the GI tract to form complexes that are poorly absorbed. Thus, the simultaneous administration of certain drugs (e.g., antacids, iron preparations, products containing calcium salts) by patients on tetracycline therapy could result in a significant decrease in the amount of antibiotic absorbed. When two drugs are recognized as having a potential to interact, there is sometimes a tendency to believe that one of them should be discontinued. In the case of the tetracycline antacid interactions, problems can be... 

Arayne MS, Sultana N. Erythromycin-antacid interaction. Phar-mazie 1993 48 599-602. 

Hobbs DC, Twomey TM Piroxicam pharmacokinetics in man aspirin and antacid interaction studies. (1979) 19, 270-81. 

Magnesium trisilicate reduces the absorption of nitrofurantoin, but the cUnical significance of this is unknown. Aluminium hydroxide is reported not to interact with nitrofurantoin. Whether other antacids interact adversely is uncertain. 

Jaffe JM, Hamilton B, Jeffers S. Nitrofurantoin-antacid interaction. Drug Intell Clin Pharm (1976) 10,419-20. 

Gupta PR, Mehta YR, Gupta ML, Sharma TN, Jain D, Gupta RB, Rifampicin-aluminium antacid interaction, J Assoc Physicians India (1988) 36, 363-4,... 

Khalil SANaggar VF,ZaghloullA, Ismail AA. In vitro anticoagulant-antacid interactions. 7/it J Pharmaceutics (19Z4) 19,307-21. 

Information seems to be limited to these studies. The indication is that large doses of some antacids can reduce the bioavailability of corticosteroids, but small doses do not, although this needs confirmation. One manufacturer of dexamethasone suggests that the doses of antacid should be spaced as far as possible from the dexamethasone, while another suggests an interval of at least 2 hours. In other similar antacid interactions 2 to 3 hours is usually sufficient. The manufacturers of deflazacort also suggest an interval of at least 2 hours between administration of deflazacort and antacids. " Concurrent use should be monitored to confirm that the therapeutic response is adequate. Information about the interaction of other corticosteroids and antacids is lacking. 

Bismuth subcarbonate [5892-10 ] (basic bismuth carbonate) is a white or pale yellow powder that is prepared by interaction of bismuth nitrate and a water-soluble carbonate. The exact composition of this dmg depends on the conditions of precipitation it corresponds approximately to the formula (Bi0)2C02. It has been widely used as an antacid (183). 

The hypotensive effects of most antihypertensive dru are increased when administered with diuretics and other antihypertensives. Many dnigp can interact with the antihypertensive drugs and decrease their effectiveness (eg, antidepressants, monoamine oxidase inhibitors, antihistamines, and sympathomimetic bronchodilators). When the ACE inhibitors are administered with the NSAIDs, their antihypertensive effect may be decreased. Absorption of the ACE inhibitors may be decreased when administered with the antacids. Administration of potassium-sparing diuretics or potassium supplements concurrently with the ACE inhibitors may cause hyperkalemia. When the angiotensin II receptor agonists are administered with... 

Antacids also have clinically significant drug interactions with tetracycline, ferrous sulfate, isoniazid, quinidine, sul-fonylureas, and quinolone antibiotics. Antacid-drug interactions are influenced by antacid composition, dose, dosage schedule, and formulation. 

Most of the interactions with mycophenolate mofetil and enteric-coated MPA are due to reductions in intestinal absorption. Aluminum-, magnesium-, or calcium-containing antacids decrease the peak level and overall exposure of MPA from either of the preparations.11 If a patient requires liquid antacids, they should be administered at least 4 hours before... 

Adverse effects with the tetracyclines include gastrointestinal upset drug interactions with dairy products, antacids, and iron and phototoxicity. Minocycline can also cause vestibular complications (headache and dizziness) and skin discoloration that is not typical with tetracycline and doxycycline.16... 

Doxycycline 100 mg twice daily Avoid in children under 8 years Can cause photosensitivity, gastrointestinal problems, tooth staining in young children many drug-drug interactions (antacids, iron, calcium)... 

There are problems as well in the absorption of certain drugs in the presence of specific food components. L-Dopa absorption may be inhibited in the presence of certain amino acids formed from the digestion of proteins [43], The absorption of tetracycline is reduced by calcium salts present in dairy foods and by several other cations, including magnesium and aluminum [115-117], which are often present in antacid preparations. In addition, iron and zinc have been shown to reduce tetracycline absorption [118], Figure 17 illustrates several of these interactions. These cations react with tetracycline to form a water-in-soluble and nonabsorbable complex. Obviously, these offending materials should not be co-administered with tetracycline antibiotics. 

Chemical drug interactions result when two administered substances combine with each other chemically Tetracyclines complex with Ca (in milk), with aluminum (Al) and magnesium (Mg) (often components of antacids), and with Fe (in some multiple vitamins) to reduce the absorption of the tetracycline antibiotic. 

Interactions Antacids ciclosporin colestipol druas metabolized bv cytochrome P450 3A4 fibrates oral-contraceptiyes warfarin niacin erythromycin diaoxin azole-antifunaals... 

Interactions. Antacids inhibit iron absorption. Combination with ascorbic acid (Vitamin C), for protecting Fe + from oxidation to Fe +, is theoretically sound, but practically is not needed. 

Drugs that may interact include antacids, cimetidine, aspirin, digoxin, phenytoin, and theophylline. 

Drugs that may interact with laxatives include mineral oil, milk or antacids, H2 antagonists, proton pump inhibitors, lipid soluble vitamins (A, D, E, and K), and tetracycline. 

Agents that may interact with cephalosporins include ethanol, aminoglycosides, anticoagulants, polypeptide antibiotics, probenecid, antacids, H2antagonists, iron... 

Drugs that may interact with nalidixic acid include theophylline, caffeine, oral anticoagulants, bacteriostatic agents, probenecid, antacids (containing magnesium, aluminum, and calcium), sucralfate, iron salts, multivitamins containing zinc, didanosine, antiarrhythmic agents, and melphalan. 

Azithromycin Drugs that may interact with azithromycin include antacids, cyclosporine, HMG-CoA reductase inhibitors, pimozide, tacrolimus, theophyllines, and warfarin. Also consider all drug interactions with erythromycin. 

Drugs that may interact with ribavirin capsules/oral solution include antacids. Drugs... 

Drugs that may interact with zalcitabine include antacids, chloramphenicol, cisplatin, dapsone, didanosine, disulfiram, ethionamide, glutethimide, gold, hydralazine, iodoquinol, isoniazid, metronidazole, nitrofurantoin, phenytoin, ribavirin, vincristine, cimetidine, metoclopramide, amphotericin, aminoglycosides, foscarnet, antiretroviral nucleoside analogs, pentamidine, and probenecid. 

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