Macrogol compound
Indications and Dose
Notes
- Time to effect: 2-3 days
- Each sachet should be dissolved in 125ml water
- May cause electrolyte disturbances and some patients find it difficult to drink the prescribed volume. Caution in elderly and fluid restricted patients
- Courses should not normally exceed 2 weeks
- Paediatric sachets are unlicensed for faecal impaction in children under 5 and for chronic constipation in children under 2 years of age
- MHRA Drug Safety Update (April 2021): Polyethylene glycol (PEG) laxatives and starch-based thickeners: potential interactive effect when mixed, leading to an increased risk of aspiration
- Addition of a PEG laxative to a liquid that has been thickened with a starch-based thickener may counteract the thickening action and result in a thin watery liquid. Avoid directly mixing together PEG laxatives and starch-based thickeners
- Where a preferred brand is recommended for a particular presentation, prescribing by brand helps ensure cost-efficient use of local NHS resources (see preferred brand link above)
Lactulose
- Oral solution 3.1-3.7g/5ml (£3.25 = 500ml)
Indications and dose
- Constipation in adults
- Initially 15ml twice daily, adjusted according to response
- Constipation in children
- 1 – 11 months: 2.5ml twice daily, adjusted according to response.
- 1 - 4 years: 2.5–10ml twice daily, adjusted according to response
- 5 - 17 years: 5–20ml twice daily, adjusted according to response
- Hepatic encephalopathy
- Adult: Adjusted according to response to 30–50 ml three times a day, subsequently adjusted to produce 2–3 soft stools per day.
Notes
- Lactulose takes up to 48 hours to work therefore, should be taken regularly rather than "when required"
- Some patients find it unpleasant to take and compliance may be a problem.
- Its main clinical benefit is in the management of hepatic encephalopathy.
- Fluid needs to be increased whilst taking lactulose
- Avoid lactulose in patients with IBS as it may increase gas production and therefore exacerbate symptoms
Phosphate (rectal)
Indication and dose
- Relief of constipation
- The contents of one single dose enema
- Perioperative use
- The contents of one single dose enema
Notes
- Time to effect: 5 minutes
- Useful to remove hard, impacted stools.
- Correct administration important to prevent damage to rectal mucosa.
- Long tube phosphate enemas are licensed for self-administration. The longer tube is to allow easier self-administration not to allow enemas to be given higher in the rectum.
- Licensed for occasional use only.
- Use of phosphate enemas are contraindicated in people who have signs of dehydration or significant renal impairment, as there is an increased risk of hypernatraemia, hyperphosphataemia, hypocalcaemia, and hypokalaemia.
- Risk of rectal gangrene in people who are systemically unwell with a history of haemorrhoids.
- Contra-indications acute gastro-intestinal conditions (including gastro-intestinal obstruction, inflammatory bowel disease, and conditions associated with increased colonic absorption)
- Conditions pre-disposing the patient to retention of the enema can make the use of the product hazardous
- Where a preferred brand is recommended for a particular presentation, prescribing by brand helps ensure cost-efficient use of local NHS resources (see preferred brand link above)
Sodium citrate
- Micro-enema 450mg in 5ml (£0.67 = 5ml enema)
Indication and dose
Notes
- Time to effect: 5-15 minutes
- Smaller volume than a phosphate enema
- Useful to remove hard, impacted stools
- Licensed for occasional use only.
- Correct administration important to prevent damage to rectal mucosa
- Use with caution in the elderly or people at risk of sodium and water retention.
Different brands may have different licensed use and dosage recommendations – refer to SPC of individual brands.