Constipation Flashcards
(24 cards)
Name three examples of bulk-forming laxatives.
Ispaghula husk, methylcellulose, sterculia.
What is the onset of action for bulk-forming laxatives?
2-3 days.
What is the mechanism of action of bulk-forming laxatives?
They increase faecal mass, which stimulates peristalsis.
What are two common side effects of bulk-forming laxatives?
Flatulence and abdominal distension.
Why is it important to drink adequate fluids when taking bulk-forming laxatives?
To avoid intestinal obstruction.
When should bulk-forming laxatives not be taken?
Before bedtime.
Name five examples of stimulant laxatives.
Bisacodyl, docusate sodium, glycerol, senna, sodium picosulfate.
What is the onset of action for oral stimulant laxatives?
6-12 hours.
What is the onset of action for stimulant laxative suppositories?
15-60 minutes.
How do stimulant laxatives work?
They increase intestinal motility by directly stimulating colonic nerves.
What additional action does docusate sodium have?
It acts as both a stimulant and a softening agent.
What additional action does glycerol have?
It acts as a rectal stimulant.
What is a common side effect of stimulant laxatives?
Abdominal pain.
When is the best time to take stimulant laxatives for an optimal effect?
At bedtime, to produce an effect the next morning.
Name two examples of faecal softeners.
Liquid paraffin and docusate sodium.
What is the onset of action for faecal softeners?
1-2 days.
How does docusate sodium work as a faecal softener?
It lowers the surface tension of stool, allowing fluid to penetrate and soften it.
Why is liquid paraffin not recommended?
It can cause anal seepage, irritation, granulomatous reactions, lipoid pneumonia, and malabsorption of fat-soluble vitamins.
Name three examples of osmotic laxatives.
Lactulose, macrogols, magnesium salts.
What is the onset of action for osmotic laxatives?
1-3 days.
What is the onset of action for magnesium salts?
A few hours.
How do osmotic laxatives work?
They retain fluid in the bowel by osmosis or alter the pattern of water distribution in the faeces.
Name three common side effects of osmotic laxatives.
Flatulence, bloating, abdominal cramps.
Why is it important to drink adequate fluids when taking osmotic laxatives?
To prevent dehydration and ensure effectiveness.
