Laxatives

Question 1

Bulk forming laxatives:
- examples
- mech action
- SE

Answer 1

Bulk forming laxatives:
- examples: ispaghula husk (fybogel)
- mech action: soluble fibre inc faecal mass and stimulates peristalsis. Takes 72 hours to work. Need to inc fluid intake
- SE: wind, bloating, cramping

Question 2

Osmotic laxatives:
- examples
- mech
- SE

Answer 2

• examples: lactulose, macrogols (movicol, laxido)
• mech: draw in water by osmosis softening stool so easier to pass
• SE: abdo cramps, diarrhea, N+V

Question 3

Stimulant laxatives:
- examples
- mech

Answer 3

• examples: senna, bisacodyl
• mech: stimulate nerves of digestive tract to cause peristalsis

Question 4

Stool softening laxatives:
- examples
- mech

Answer 4

• examples: docusate
• mech: decrease surface tensions of faecal mass and inc intestinal fluid in stool

Question 5

Short term constipation mx
Opioid induced
impaction
chronic
-preg/breast feeding

Answer 5

Short term constipation mx: bulk forming, add osmotic, add stimulant
Opioid induced: osmotic + stimulant, add softener
impaction: depends on stool consistency but either stimulant or osmotic
chronic: same as short term
-preg/breast feeding: bulk forming laxatives

Question 6

Ferrous sulfate
- se

Answer 6

• continue to take 3 months after replenished levels
• se: nausea, abdo pain, constip, diarr, black stool