Gaviscon

What is Gaviscon?

Gaviscon is an over-the-counter medication widely used for the symptomatic relief of gastro-oesophageal reflux, heartburn, and acid indigestion. It serves as a rapid-acting reflux suppressant designed to alleviate discomfort caused by gastric acid backing up into the esophagus.

Unlike simple antacids that purely neutralize stomach acid, Gaviscon utilizes a unique mechanism known as raft formation. When the sodium alginate reacts with gastric acid, it synthesizes into a thick, neutral gel that traps carbon dioxide bubbles. This physical barrier floats on top of the stomach contents, acting like a plug at the esophageal sphincter to prevent acid from rising.

Generic Names:

• Sodium Alginate / Sodium Bicarbonate / Calcium Carbonate: Widely used globally as the standard combination for alginate-based reflux suppressants.

Global Brand Names:

Gaviscon is marketed under several specific formulations in Hong Kong and internationally.

• Gaviscon (嘉胃斯康): Widely available in Hong Kong pharmacies and supermarkets in liquid, tablet, and sachet forms.
• Gaviscon Advance (嘉胃斯康加强版): Features a higher concentration of sodium alginate for more persistent reflux symptoms in the Hong Kong market.
• Gaviscon Dual Action (嘉胃斯康雙重效能): Combines an antacid and alginate for both acid neutralization and raft formation, readily available in Hong Kong.

These names all refer to the same medication. It's important to note that while the active ingredients are the same, different countries may have different regulations and available medication formulations.

What is Gaviscon used for?

Gaviscon is used to relieve:

• Heartburn and burning sensations in the chest or throat.
• Acid regurgitation and sour taste in the mouth.
• Indigestion and dyspepsia related to reflux.
• Symptoms associated with a hiatus hernia.

How do you use Gaviscon?

Availability:

• Liquid suspensions.
• Chewable tablets.
• Powder sachets.

Dosage Information:

• Adults and children over 12 years: 10–20 ml or 2–4 chewable tablets after meals and at bedtime.
• Children 6–12 years: 5–10 ml after meals and at bedtime.
• Infants: Only use specialized infant powder formulations under direct medical supervision.

Suitability:

• Adults and elderly: Yes.
• Pregnant or breastfeeding women: Yes.
• Children over 12: Yes.
• Children under 12: Yes, with adjusted doses.
• Infants under 1 year: No, unless explicitly prescribed by a doctor.

Who cannot take Gaviscon?

Allergies and unsuitability:

• Rare, but possible allergic reactions.

Conditions where the drug should not be used:

• Severe renal impairment.
• Strictly restricted sodium diets, such as those with severe congestive heart failure.
• Hypercalcaemia or recurrent calcium-containing kidney stones.

Gaviscon is generally well-tolerated when taken at the recommended doses, and side effects are uncommon. Mild issues can include slight constipation, diarrhea, or temporary bloating and belching as the active carbonates release trapped gas in the stomach.

Severe side effects are highly unusual but can manifest as allergic reactions, such as hives, bronchospasm, or anaphylaxis, which require immediate medical attention. Overuse should be avoided, as chronic reliance on the medication can mask symptoms of more severe underlying conditions like peptic ulcers or esophageal issues.

• Leave a two-hour gap before taking antibiotics, iron supplements, or antifungals to prevent interference with their absorption.
• Monitor sodium intake if you are on a restricted salt diet, as Gaviscon contains significant amounts of sodium.
• Do not exceed the recommended dose to avoid masking serious underlying gastric conditions.
• Check with a doctor if you have phenylketonuria, as some chewable tablets may contain aspartame.

Storage information:

• Keep in a cool, dry place below 30°C.
• Do not freeze liquid suspensions.
• Keep out of reach of children.

Handling instructions:

• Shake liquid suspensions vigorously before measuring the dose.
• Use the measuring device or cup that comes with the medication for the correct dose.
• Chew tablets thoroughly before swallowing to ensure the protective raft forms correctly in the stomach.

Where is Gaviscon available in Hong Kong?

In Hong Kong, Gaviscon is classified as an "Over-the-Counter" medication. This means it can be sold freely to the public without a prescription.

Patients can legally obtain this medication at general chain drug stores like Mannings and Watsons, local supermarkets, and registered pharmacies across the city.