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Stimulant Laxative / Bowel Preparation Agent Pregnancy: Caution — avoid in first trimester; limited data. Short-term use acceptable in second/third trimester for severe constipation.

Sodium Picosulfate

Brand names: Dulcolax Pico, Laxoberal, Picolax (with magnesium citrate)

Adult dose

Dose: Constipation: 5–10mg at night (liquid drops: 5–10mg = 10–20 drops). Bowel preparation (Picolax sachet): 1 sachet dissolved in cold water in the morning and 1 sachet 6 hours later (day before procedure).
Route: Oral
Frequency: Once daily at night (constipation); as directed (bowel preparation)
Max: 10mg/day (constipation)
Bowel preparation: Picolax contains sodium picosulfate + magnesium oxide + citric acid — releases magnesium citrate in situ. Ensure adequate hydration during bowel preparation. Caution in renal impairment (magnesium accumulation from Picolax component).

Paediatric dose

Route: Oral
Frequency: Once daily at night
Max: 5mg/day
BNF for Children: 1 month–4 years (off-label): 2.5mg/day; 4–10 years: 2.5–5mg/day; >10 years: 5–10mg/day. Liquid drops: 1 drop = 0.5mg sodium picosulfate. Source: BNF for Children 2024.

Dose adjustments

Renal

Avoid Picolax (bowel preparation) if eGFR <30 — risk of hypermagnesaemia from magnesium citrate component.

Hepatic

No dose adjustment required.

Clinical pearls

  • Picolax bowel preparation: produces watery diarrhoea starting 2–4 hours after first sachet. Patient must drink at least 2 litres of clear fluid throughout the day.
  • Liquid drops (Laxoberal): useful for patients who cannot swallow tablets — each drop = 0.5mg sodium picosulfate.
  • Renal caution with Picolax: magnesium citrate component causes severe hypermagnesaemia in eGFR <30 — use macrogol-based preparation (Moviprep) instead.
  • Effective laxative at lower doses (2.5–5mg) with less cramping than bisacodyl — preferred by some patients for constipation.

Contraindications

  • Intestinal obstruction
  • Severe dehydration
  • Severe renal impairment (for Picolax preparation — magnesium toxicity)
  • Acute inflammatory bowel disease (active)

Side effects

  • Abdominal cramping
  • Diarrhoea (dose-dependent)
  • Nausea
  • Electrolyte disturbance (bowel preparation — dehydration, hyponatraemia, hypokalaemia)
  • Hypermagnesaemia (Picolax in renal impairment)

Interactions

  • Broad-spectrum antibiotics: may reduce efficacy (alter colonic bacterial conversion of picosulfate to active form)

Monitoring

  • Hydration status
  • Electrolytes (bowel preparation)
  • Renal function (if Picolax used)

Reference: BNFc; BNF 90; BSG Bowel Preparation Guidelines; SPC Picolax; SPC Laxoberal. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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