Movicol (Sodium Hydrogen Carbonate, Potassium Chloride, Sodium Chloride, Macrogol 3350)

Movicol, an osmotic laxative, is indicated for conditions that impair normal bowel function by reducing stool hardness and promoting regular evacuation.

• Constipation: softens and increases the volume of stool, helping patients achieve regular bowel movements and relieve abdominal discomfort.
• Chronic constipation: provides ongoing stool hydration and bulk, supporting long‑term bowel regularity in individuals with persistent evacuation difficulties.
• Fecal impaction: hydrates hardened stool, facilitating safe disimpaction and restoration of normal bowel transit.

• Macrogol 3350, a high‑molecular‑weight polyethylene glycol, is not absorbed from the gut; it creates an osmotic gradient that draws water into the intestinal lumen. The added electrolytes (sodium hydrogen carbonate, potassium chloride, sodium chloride) help maintain electrolyte balance while the increased water content softens stool, expands its volume, and stimulates peristalsis, thereby promoting bowel movements.

Movicol may cause a range of adverse reactions, most of which are mild and transient.

Common Side Effects

• Abdominal bloating: feeling of fullness or swelling in the abdomen.
• Nausea: mild sensation of wanting to vomit.
• Diarrhoea: loose, watery stools occurring more frequently.
• Flatulence: increased gas production leading to passing gas.

Serious or Rare Side Effects

• Severe dehydration: significant loss of body fluids requiring medical attention.
• Electrolyte imbalance: abnormal levels of sodium, potassium or chloride.
• Allergic reaction: rash, itching, swelling, or difficulty breathing.

Before initiating Movicol, consider several safety measures to minimise risks.

• Assess renal function: evaluate kidney health prior to therapy.
• Monitor electrolyte status: check sodium and potassium levels during prolonged use.
• Adjust dose in elderly: start with a lower dose due to slower gastrointestinal transit.
• Avoid concurrent strong laxatives: may increase risk of diarrhoea and dehydration.
• Pregnancy and breastfeeding: use only if clearly needed after risk‑benefit assessment.
• Store at ambient temperature: keep in original container, protect from moisture and heat.

Movicol can interact with other medicines, requiring attention to avoid complications.

Major Interactions (Avoid)

• Loop diuretics: may exacerbate electrolyte loss leading to hypokalaemia.
• Other osmotic laxatives (e.g., lactulose): combined effect can cause severe diarrhoea and dehydration.

Moderate Interactions (Monitor Closely)

• Antacids containing magnesium or aluminium: may affect electrolyte absorption.
• NSAIDs: may increase risk of renal impairment when combined with fluid loss.
• Oral rehydration solutions: monitor electrolyte balance if used concurrently.