Patient info

Maalox 175mg/200mg Oral Suspension – Summary of Product Characteristics (SmPC) for healthcare professionals

The Summary of Product Characteristics (SmPC) is written for healthcare professionals. Patients will find plain advice in the patient information leaflet: how to take, side effects, other medicines, pregnancy and breast-feeding.

Updated:
Key facts
Status:
No longer supplied
Medicine strength:
175 mg / 200 mg
Contains active substances:

Summary of Product Characteristics (SmPC) - Maalox 175 mg / 200 mg oral suspension

1 NAME OF THE MEDICINAL PRODUCT

Maalox 175mg/200mg Oral Suspension

2 QUALITATIVE AND QUANTITATIVE COMPOSITION

Each 5 ml of oral solution contains:

Aluminium hydroxide 175mg

Magnesium hydroxide 200mg

Excipients with known effect:

This medicinal product contains 0.0068 mmol (0.157 mg) of sodium and 50 mg of sorbitol per 5 ml dose.

For the full list of excipients, see section 6.1.

3 PHARMACEUTICAL FORM

Oral suspension

White oral suspension, homogenous after shaking

4 CLINICAL PARTICULARS

4.1 Therapeutic indications

Antacid therapy in gastric and duodenal ulcer, gastritis, heartburn and gastric hyperacidity.

4.2 Posology and method of administration

Posology

Adults (including the elderly):

10 – 20 ml taken 20 minutes to one hour after meals and at bedtime or as required. Maalox can be taken with water or milk if required.

Paediatric population:

Not recommended for children under 14 years.

Method of administration

For oral administration.

Shake before use.

4.3 Contraindications

Maalox should not be used in patients who are severely debilitated or suffering from renal insufficiency, or if there is severe abdominal pain and/or the possibility of bowel obstruction.

Hypersensitivity to the active substances or to any of the excipients listed in section 6.1.

4.4 Special warnings and precautions for use

Aluminium hydroxide may cause constipation and magnesium salts overdose may cause hypomotility of the bowel; large doses of this product may trigger or aggravate intestinal obstruction and ileus in patients at higher risk such as those with renal impairment, or the elderly.

Aluminium hydroxide is not well absorbed from the gastrointestinal tract, and systemic effects are therefore rare in patients with normal renal function. However, excessive doses or long-term use, or even normal doses in patients with low-phosphorus diets may lead to phosphate depletion (due to aluminium-phosphate binding) accompanied by increased bone resorption and hypercalciuria with the risk of osteomalacia. Medical advice is recommended in case of long-term use or in patients at risk of phosphate depletion.

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 dementia, microcytic anemia.

Aluminium hydroxide may be unsafe in patients with porphyria undergoing hemodialysis.

This product contains sorbitol (E420). Patients with rare hereditary problems of fructose intolerance should not take this medicine.

This medicinal product contains less than 1 mmol sodium (23mg) per dose, i.e. essentially “sodium free”.

4.5 Interaction with other medicinal products and other forms of interaction

Aluminium-containing antacids are known to interfere with the absorption of drugs notably H2 antagonists, atenolol, bisphosphonates, chloroquine, chlorpromazine, cefdinir, cefpodoxime, ciprofloxacin, cyclines, dasatinib monohydrate, diflunisal, digoxin, dexamethasone, eltrombopag olamine, elvitegravir, ethambutol, fluoroquinolones, glucocorticoids, hydroxychloroquine, indomethacin, iron salts, isoniazid, ketoconazole, levothyroxine, lincosamides, metoprolol, nilotinib, phenotiazine neuroleptics, penicillamine, propranolol, raltegravir potassium, rifampicin, rilpivirine, riociguat, rosuvastatin, sodium fluoride, antiviral treatment combination of tenofovir alafenamide fumarate/emtricitabine/bictegravir sodium, tetracyclines, and vitamins.

With the integrase inhibitors (dolutegravir, raltegravir, bictegravir) the combination should be avoided (please refer to their SmPC for dose recommendations).

As a precaution, staggering the administration times of any orally administered drug and the antacid by at least 2 hours (4 hours for the fluoroquinolones).

Polystyrene sulphonate

Caution is advised when used concomitantly with polystyrene sulphonate due to the potential risks of reduced effectiveness of the resin in binding potassium, of metabolic alkalosis in patients with renal failure (reported with aluminium hydroxide and magnesium hydroxide), and of intestinal obstruction (reported with aluminium hydroxide).

Aluminium hydroxide and citrates may result in increased aluminium levels, especially in patients with renal impairment.

Urine alkalinisation secondary to administration of magnesium hydroxide may modify excretion of some drugs; thus, increased excretion of salicylates has been seen.

4.6 Fertility, Pregnancy and lactation

Pregnancy

There are no or limited amount of data from the use of aluminium hydroxide and magnesium hydroxide in pregnant women. Animal studies are insufficient with respect to reproductive toxicity (see section 5.3). Maalox is not recommended during the first trimester of pregnancy and in women of childbearing potential not using contraception. Caution should be exercised when prescribing to pregnant and lactating women.

Breast-feeding

Because of the limited maternal absorption, when used as recommended, aluminium hydroxide and magnesium salt combinations are considered compatible with lactation.

No effects on the breastfed newborns/infant are anticipated since the systemic exposure of the breast-feeding woman to aluminium hydroxide and magnesium hydroxide is negligible.

Fertility

No fertility data is available.

4.7 Effects on ability to drive and use machines

None stated.

4.8 Undesirable effects

The following CIOMS frequency rating is used, when applicable: Very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100), rare (≥1/10,000 to <1/1,000), very rare (<1/10,000), not known (cannot be estimated from available data)

Immune system disorders

Not known: hypersensitivity reactions, such as pruritus, urticaria, angioedema and anaphylactic reactions

Gastrointestinal disorders

Gastrointestinal side effects are uncommon.

Uncommon: diarrhoea or constipation (see section 4.4)

Frequency not known: Abdominal pain

Metabolism and nutrition disorders

Very rare: Hypermagnesemia, including observations after prolonged administration of magnesium hydroxide to patients with renal impairment.

Frequency not known:

Hyperaluminemia.

Hypophosphatemia, in prolonged use or at high doses or even normal doses of the product in patients with low-phosphorus diets, which may result in increased bone resorption, hypercalciuria, osteomalacia (see section 4.4).

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

4.9 Overdose

Serious symptoms are unlikely following overdose. Discontinue medication and correct fluid deficiency if necessary.

Reported symptoms of acute overdose with aluminium hydroxide and magnesium salts combination include diarrhoea, abdominal pain, vomiting.

Large doses of this product may trigger or aggravate intestinal obstruction and ileus in patients at risk (see section 4.4).

Aluminium and magnesium are eliminated through urinary route; treatment of acute overdose consists of administration of IV Calcium Gluconate, rehydration and forced diuresis. In case of renal function deficiency, haemodialysis or peritoneal dialysis is necessary.

5 PHARMACOLOGICAL PROPERTIES

5.1 Pharmacodynamic properties

Pharmacotherapeutic group: Antacids; aluminium compound combinations ATC code: A02AB10

Maalox is a balanced mixture of two antacids; aluminium hydroxide is a slow-acting antacid and magnesium hydroxide is a quick-acting one. The two are frequently combined in antacid mixtures. Aluminium hydroxide on its own is an 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. Gastro-intestinal side effects are thus rare with Maalox and this makes it especially suitable when long term therapy is necessary.

5.2 Pharmacokinetic properties

The absorption of aluminium and magnesium from antacids is small. Aluminium hydroxide is slowly converted to aluminium chloride in the stomach. Some absorption of soluble aluminium salts occurs in the gastro-intestinal tract with urinary excretion. Any absorbed magnesium is likewise excreted in the urine. Aluminium containing antacids should not be administered to patients with renal impairment where increased plasma concentration may occur.

5.3 Preclinical safety data

Non-clinical data are limited and are considered insufficient with respect to repeated dose toxicity, genotoxicity and toxicity to reproduction and development.

6 PHARMACEUTICAL PARTICULARS

6.1 List of excipients

Hydrochloric acid (10%)

Citric acid (monohydrate)

Peppermint oil

Mannitol (E421)

Domiphen bromide

Saccharin sodium

Sorbitol liquid 70% (not crystallising) (E420)

Hydrogen peroxide solution 30%

Purified water

6.2 Incompatibilities

None stated.

6.3 Shelf life

3 years

After first opening: 6 months

6.4 Special precautions for storage

Do not store above 25°C.

6.5 Nature and contents of container

Polyethylene terephthalate (PET) bottle with polypropylene (PP) closure and polyethylene (PE/LDPE) liner: 250ml

6.6 Special precautions for disposal

No special requirements.

7 MARKETING AUTHORISATION HOLDER

Opella Healthcare UK Limited, trading as Sanofi 410 Thames Valley Park Drive,

Reading,

Berkshire,

RG6 1PT,

United Kingdom.

8 MARKETING AUTHORISATION NUMBER(S)

PL 53886/0039

9 DATE OF FIRST AUTHORISATION/RENEWAL OF THE

AUTHORISATION

31/01/2025

10 DATE OF REVISION OF THE TEXT

31/01/2025

About this document

Source: MHRA - Medicines and Healthcare products Regulatory Agency (products.mhra.gov.uk) · Marketing authorisation: PL 53886/0039

Last revision stated in the text: 31 January 2025 · MHRA data as of 13 October 2026

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The information on this site does not replace the advice of a doctor or pharmacist.

Facts about Maalox 175 mg / 200 mg oral suspension

Active substances Aluminium hydroxide, Magnesium hydroxide
Strength 175 mg / 200 mg
Pharmaceutical form Oral suspension
White oral suspension, homogenous after shaking
How is it taken Oral
Excipients Hydrochloric acid (10%), Citric acid (monohydrate), Peppermint oil, Mannitol (E421), Domiphen bromide, Saccharin sodium, Sorbitol liquid 70% (not crystallising) (E420), Hydrogen peroxide solution 30%, Purified water
Is it available? No, all its packs are listed as discontinued (NHS Dictionary of Medicines and Devices – not a record of current supplies)
Shelf life 3 years
After first opening: 6 months
Storage Do not store above 25°C.
Drug group (ATC) Antacids; aluminium compound combinations
  1. A Alimentary tract and metabolism drugs
    1. A02 Drugs for acid related disorders
      1. A02A Antacids
        1. A02AD Antacids containing combinations and complexes of aluminium, calcium and magnesium compounds
          1. A02AD01 ordinary salt combinations
Marketing authorisation PL 53886/0039 (first authorised 31 January 2025)
Marketing authorisation holder Opella Healthcare UK Limited, trading as Sanofi 410 Thames Valley Park Drive
Codes BNF 01010100

Sources: the MHRA product information (products.mhra.gov.uk) and the NHS Dictionary of Medicines and Devices (dm+d), release 10.2.0 of 19 October 2026, NHS Business Services Authority. Contains public sector information licensed under the Open Government Licence v3.0.