- magnesium hydroxide
GSL: General Sales List
This information is intended for use by health professionals
Magnesium Hydroxide Mixture
Magnesium Hydroxide Paste Concentrated 1.325g/5ml
Excipient(s) with known effect:
Sodium benzoate 2.5mg/5ml
For a full list of excipients see section 6.1
1. For relief of the symptoms of flatulence, heartburn, dyspepsia and indigestion
2. As a laxative for relief of occasional constipation
Recommended doses and dosage schedule
1. As an antacid
Adults, the elderly and children over 12 years: one to two 5ml spoonfuls in a little water when required. Children under 12 years: not suitable.
2. As a laxative
Adults, the elderly and children over 12 years: 25 - 50ml (five to ten 5ml spoonfuls) in a glass of water at bedtime.
Children under 12 years: not suitable.
Directions for use: Shake the bottle.
Contraindicated in severe renal failure, acute gastrointestinal conditions and in hypersensitivity to magnesium salts or any of the other ingredients.
Use with caution in the elderly and debilitated and in patients with impaired liver function. Also in patients with impaired kidney function as hypermagnesaemia may result.
Keep all medicines away from children.
If constipation persists consult your doctor.
Not suitable for children under 12.
Discard any unused mixture 3 months after opening.
In young children the use of magnesium hydroxide can produce a hypermagnesemia, especially if they present renal impairment or dehydration.
Excipient warnings :
This medicine contains less than 1mmol sodium (23mg) per 5ml dose, that is to say essentially 'sodium-free'.
This medicine contains 2.5mg sodium benzoate in each 5ml dose, which is equivalent to 0.05% w/v.
As a precaution for antacids, in order to minimise the risk of interactions affecting pharmacokinetics of concomitantly administered products, drug administrations should be separated by approximately 2 to 3 hours.
Magnesium salts reduce the absorption of a number of other drugs taken concomitantly. These include ACE inhibitors (captopril, enalapril, and fosinapril), antibacterials and antifungals (azithromycin, cefaclor, cefpodoxime, isoniazid, itraconazole, nitrofurantoin, rifampicin, tetracyclines, ketoconazole and the quinolone group of antibacterials); antivirals (atazanavir, fosamprenavir, tipranavir); antihistamines (fexofenadine); bisphosponates, corticosteroids (deflazacort); digoxin, dipyridamole, diflunisal, antiepileptics (gabapentin and phenytoin), ulcer healing drugs (lansoprazole); levothyroxine, mycophenolate, iron preparations, lipid regulating drugs (rosuvastatin); antipsychotics (sulpiride, phenothiazines), chloroquine, hydrochloroquine, proguanil, and penicillamine. Concomitant use with sodium polystyrene sulphonate may produce metabolic alkalosis. Alkaline urine due to some antacids increases excretion of aspirin. Antacids should be avoided with nilotinib.
Antacids possibly reduce absorption of bile acids.
Urine alkalinisation secondary to administration of magnesium hydroxide may modify excretion of some drugs; thus, increased excretion of salicylates has been seen.
As with all other medicines, use of this product should be avoided in the above conditions unless recommended by a doctor.
System Organ Class
Very Rare (<1/10,000)
Not known (cannot be estimated from the available data)
Metabolism and nutrition disorders
Hypermagnesmia. Observed after prolonged administration of magnesium hydroxide to patients with renal impairment.
Abdominal pain, Diarrhoea (a dose-dependent effect), Colic.
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 the Yellow Card Scheme at www.mhra.gov.uk/yellowcard or search for 'MHRA Yellow Card' in the Google Play or Apple App Store.
Excessive use of magnesium containing antacids has rarely resulted in hypermagnesaemia, symptoms of which include flushing of the skin, thirst, respiratory depression, cardiac arrhythmias, coma and cardiac arrest.
Treatment should consist of the administration of calcium gluconate injection 10% intravenously at a dose of 10 - 20ml, to counteract respiratory depression or heart block. If renal function is normal, sufficient fluids should be given to aid removal of magnesium from the body. Dialysis may be necessary in patients with impaired renal function or severe hypermagnesaemia.
Magnesium hydroxide is an antacid with slow neutralising action and a mild laxative action.
Magnesium salts are poorly absorbed following oral administration. Approximately one third of magnesium is absorbed from the small intestine, and excreted mainly in the urine with small amounts in breast milk and saliva.
Sodium Benzoate (E211)
12 months unopened, 3 months after first opening.
Do not freeze
Do not store above 25°C
500ml: Glass bottle with white plastic child resistant cap with EPE/Saranex liner.
Thornton & Ross Ltd
27/09/88 / 24/09/2001