Irish Medicines Board
Summary of Product Characteristics
1 NAME OF THE MEDICINAL PRODUCT
Maalox 400mg/400mg Chewable Tablets
2 QUALITATIVE AND QUANTITATIVE COMPOSITION
Each tablet contains:
400 mg of Aluminium oxide, hydrated
400 mg of Magnesium Hydroxide.
Excipients: Each tablet contains 192mg confectioners sugar (containing no less than 97% sucrose), 125mg sorbitol
(E420) and 59.2 mg sucrose
For a full list of excipients, see section 6.1.
3 PHARMACEUTICAL FORM
Flat, circular, bevel-edged white chewable tablet of diameter 1.4 cm with 'Mx' engraved on both sides and having an
odour of peppermint.
4 CLINICAL PARTICULARS
4.1 Therapeutic Indications
For the relief of the symptoms of dyspepsia.
4.2 Posology and method of administration
The route of administration is oral.
Adults: 1-2 tablets chewed 4 times daily, taken 20 minutes to 1 hour after meals and at bedtime, or as directed by the
physician. A maximum of 8 tablets in a 24 hour period should not be exceeded, nor should the maximum dose continue
for more than 2 weeks except under the direction of the physician.
Use in severely debilitated patients or in those suffering from kidney failure.
Use in patients who are allergic to any of the ingredients in Maalox Chewable Tablets.
4.4 Special warnings and precautions for use
Aluminium hydroxide may cause constipation due to its astringent action, this effect may be balanced by the cathartic
effect of the magnesium salts.
Aluminium hydroxide may lead to a phosphate depletion syndrome, particularly in patients on a low phosphate diet e.g.
Magnesium salts may cause central nervous depression in the presence of renal insufficiency and should be used with
caution in patients with advanced renal disease.
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Irish Medicines Board
In patients with renal impairment, plasma levels of both aluminium and magnesium increase. In these patients, a long-
term exposure to high doses of aluminium and magnesium salts may lead to encephalopathy, dementia microcytis
anemia or worsen dialysis-induced osteomalacia.
The prolonged use of antacids in patients with renal failure should be avoided.
Care should be observed if used by diabetics because of the sugar content in the tablet.
Aluminium hydroxide may be unsafe in patients with porphyria undergoing hemodialysis because it has been shown
that aluminium may be involved in porphyrin metabolism normalities.
Patients with rare hereditary problems of fructose intolerance, glucosegalactose malabsorption or sucrase-isomaltase
insufficiency should not take this medicine.
4.5 Interaction with other medicinal products and other forms of interaction
This product may form complexes with certain drugs, e.g. tetracyclines, digoxin and vitamins, resulting in decreased
absorption. This should be borne in mind when concomitant administration is considered.
Concomitant use with quinidines may increase the serum levels of quinidine and lead to quinidine overdosage.
Aluminium-containing antacids may prevent the proper absorption of H2 antagonists, atenolol, chloroquine, cyclines,
diflunisal, digoxin, diphosphonates, ethambutol, fluoroquinolones, sodium fluorure, glucocorticoids, indometacine,
isoniazide, kayexalate, ketoconazole, lincosamides, metoprolol, neuroleptics phenothiazines, penicillamine,
propranolol, iron salts. Staggering the administration times of the interacting drug and the antacid by at least 2 hours (4
hours for the fluoroquinolones) will often help avoid undesirable drug interactions.
Aluminium hydroxide and sitrates may result in increased aluminium levels, especially in patients with renal
4.6 Fertility, pregnancy and lactation
The product should not be used during pregnancy unless considered essential by the physician.
4.7 Effects on ability to drive and use machines
4.8 Undesirable effects
Gastrointestinal side-effects are uncommon.
Occasionally high doses of antacids may cause diarrhoea or constipation.
Serious symptoms are unlikely following overdosage.
5 PHARMACOLOGICAL PROPERTIES
5.1 Pharmacodynamic properties
Maalox is a balanced mixture of two antacids: aluminium hydroxide is a slow acting antacid and magnesium
hydroxide is a fast acting one. The two are frequently combined in antacid mixtures. Aluminium hydroxide on its own
is astringent and may cause constipation. This effect is balanced by the effect of magnesium hydroxide, which, in
common with other magnesium salts, may cause diarrhoea.
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