Cancer Care - Laxatives

Question 1

Give some examples of stimulant laxatives

Answer 1

• Bisacodyl
• Sodium picosulfate
• Senna
• Co-danthramer
• Co-danthrusate

Question 2

What is co-danthramer?

Answer 2

Stimulant laxative
-combined stimulant softener laxative that words to increase peristalsis and mucous secretion. Agent reserved for treatment of terminally ill patients, as rodent studies indicate potentially carcinogenic risk

Question 3

What is Senna?

Answer 3

• Stimulant laxative:
• natural plant extra that leads to increased colonic motility, reduced intestinal fluid absorption and increased mucous excretion
• Senocot (brand name)
• Takes 6-12 hours to work

Question 4

What is bisacodyl? What class of laxative does this belong to and what is the MoA? Give the brand name

Answer 4

• Stimulant laxative: increase intestinal motility
• SEs: cause abdominal cramp - CI in obstruction
• Takes 6-12h to work
• Brand name of bisacodyl: dulcolax

Question 5

What are bulk forming laxatives? Give some side effects, indication and names

Answer 5

• Work by increasing bulk/weight of stools, stimulating bowels
• Good for adults with small hard stools in which fibre cannot be easily added to diet
• Take 2-3 days to work
• May exacerbate flatulence, bloating and cramping and must maintain adequate fluids to present bowel obstruction

Names

• Fybogel: ispaghula husk
• Methycellulose

Question 6

What are glycerine suppositories? How do these work?

Answer 6

• Faecal softener laxative

- hyperosmotic agent commonly presented as a suppository. Can cause local irrigation of the colon to exert effect

Question 7

What is docusate?

Answer 7

• Faecal softener laxative
• Stool softener with mild stimulant effect that acts to decrease surface tension at the oil-water interface of the stool, resulting in incorporation of the water in the stool

Question 8

What is macrogol? What are the brand names found in hospital?

Answer 8

• Osmotic laxative
• iso-osmotic suspension, that adds bulk, increase stool water content to soften and stimulates colonic propulsion and lubrication
• Laxido, movicol

Question 9

What is lactulose? Explain MoA and give another example of laxative in this category

Answer 9

• Osmotic laxative: disaccharide that cannot be systemically absorbed from the GI tract (draws in water from bowel), leading to stool softening by osmosis
• Take 2-3 days to work
• Polyethylene glycol

Question 10

How do you manage constipation of short duration?

Answer 10

In the management of short-duration constipation (where dietary measures are ineffective)

1. bulk-forming laxative, ensuring adequate fluid intake.
2. If stools remain hard, add or switch to an osmotic laxative.
3. If stools are soft but difficult to pass or the person complains of inadequate emptying, a stimulant laxative should be added.

Question 11

How do you manage opioid induced constipation?

Answer 11

• Osmotic laxative + stimulant laxative

- Bulk forming laxatives should be avoided

Question 12

How do you manage faecal impaction?

Answer 12

Based on stool consistency:

• Hard stools: high dose of oral macrogol
• Soft stools or have been on high dose macrogol for a few days: start/add oral stimulant laxative

Question 13

How do you manage chronic constipation?

Answer 13

• Bulk forming laxative + good hydration
• If stool remains hard, change or add an osmotic laxative (eg macrogol) or lactulose if osmotic doesn’t work/isn’t tolerated