CHOICE OF LAXATIVES

Laxatives should be prescribed on a regular basis as soon as weak or strong opioids are prescribed (except those with ileostomy or diarrhoea), with full explanation to the patient.

Many ill patients will not tolerate high fibre diet or bulk forming laxatives and these are not usually recommended in palliative care. Many patients become expert at adjusting their own laxatives. However a regular regime will be essential for those on opioids

A combination of stimulant laxative with a softening/ osmotic agent is a good first choice.

25% of patients on oral laxatives may still need rectal measures at times.

ORAL PREPARATIONS

The information below includes commonly used laxatives – higher than licensed doses may be recommended for opioid induced constipation and for more resistant cases (seek specialist advice).

Stimulants

Increase intestinal motility. Often cause abdominal cramp / colic. Do not use if patient has complete bowel obstruction.

Senna

Onset of action: 6–12 hours

Starting dose: 15mg OD – BD

Formulations: Tablets, syrup, and granules

Bisacodyl

Onset of action: 10–12 hours

Starting dose: 5mg–20mg nocte

Formulations: Tablets

Sodium picosulphate

Onset of action: 6–14 hours

Starting dose: 5mg–10mg nocte. Stimulant laxative indicated where other stimulant laxatives have failed.

Formulations: Capsules and elixir.

Softeners

Faecal softening by acting as a surface wetting agent.

Docusate sodium

(also stimulant action in higher doses)

Onset of action: 1–3 days

Starting dose: 100mg-200mg bd

Formulations: Capsules and elixir

Combined softeners and stimulants

Combines faecal softening and increased intestinal motility. Do not use if patient has complete bowel obstruction.

Dantron stains urine red (warn patient) and can also cause perianal skin irritation, especially in incontinent patients. It may be prudent to avoid dantron-containing products in dying patients or those who are faecally incontinent or have a colostomy.

Co-danthrusate

Co-danthrusate (dantron 50mg, docusate 60mg)

Onset of action: 6–12 hours

Starting dose: 1–2 capsules at bedtime

Formulations: Capsules 50/60

Osmotic agents - oral

Increase the amount of water in the large bowel. Avoid if patient is dehydrated or has electrolyte disturbances. Avoid if patient has complete bowel obstruction.

Macrogol

Macrogol preparations may be preferable to lactulose if additional softener is required.
Up to 8 sachets a day may be used in faecal impaction.

Onset of action: 1–2 days

Starting dose: 1 sachet dissolved in 125ml. Water or Concentrated oral liquid 25mL dissolved in 100ml water

Formulations: Macrogol oral powders (brands include Movicol®, Dulco-balance®, Laxido® , Molaxole®)

Lactulose

Lactulose alone in usual recommended doses is not effective for opioid induced constipation and should not be used in patients with inadequate fluid intake.

Lactulose can cause flatulence and abdominal cramps.

Onset of action: 1–2 days

Starting dose: 15ml bd

Formulations: Solution

RECTAL PREPARATIONS

Stimulants

Local stimulation of intestine. Do not use if patient has complete bowel obstruction.

Bisacodyl suppositories

Onset of action: 20–60 minutes

Starting dose: 10mg suppository

Glycerol suppositories

Onset of action: 1–6 hours

Starting dose: 4g suppository

Softeners

Lubricate and soften faeces.

Arachis oil enemas

DO NOT USE IN PATIENTS WITH PEANUT ALLERGY

Onset of action: Normally administered at night (retention enema)

Starting dose: 130ml (warm before use)

Docusate sodium enema

Onset of action: 15–60 minutes. Normally administered at night (retention enema).

Starting dose: Dose 120mg in 10g pack.

Osmotic agents - oral

Increase the amount of water in the large bowel.

Phosphate enemas

Ensure the patient is hydrated and that recent U and Es have been taken.

Onset of action: 15–60 minutes

Starting dose: 1 enema

Sodium citrate enema

Onset of action: 15–60 minutes

Starting dose: 5ml enema

Spinal cord compression:

If normal sphincter sensation and function is present, titrate laxatives as normal, avoid excessive softening.

If normal sphincter sensation and function is absent, bisacodyl suppositories or other rectal interventions should be prescribed, aiming for a planned bowel action every two to three days.

If standard measures fail

In patients recognised to have significant and on going constipation as a result of opioid use despite measures above, specialist advice may be sought regarding the use of drugs such as the Oxycodone/Naloxone combination (Targinact®) and the opioid antagonists methylnaltrexone injection (Relistor®) and oral Naloxegol (Moventig®) .

DISCLAIMER

This Guide is intended for use by healthcare professionals and the expectation is that they will use clinical judgement, medical, and nursing knowledge in applying the general principles and recommendations contained within. They are not meant to replace the many available texts on the subject of palliative care.
Some of the management strategies describe the use of drugs outside their licensed indications. They are, however, established and accepted good practice. Please refer to the current BNF for further guidance.
While WMPCPS takes every care to compile accurate information , we cannot guarantee its correctness and completeness and it is subject to change. We do not accept responsibility for any loss, damage or expense resulting from the use of this information.