laxatives

Question 1

name the key laxative

Answer 1

senna

Question 2

used to treat what?

Answer 2

constipation (orally)

as suppositories for faecal impaction (rectally)

Question 3

MOA

Answer 3

increases water and electrolyte secretion from the colonic mucosa
increase content of colon and volumne which stimulates perstialsis and therefore movement

Question 4

disadvantage of suppositories

Answer 4

localised effect to rectal region

Question 5

side effects

Answer 5

abdominal pain or cramping

diarrhoea

Question 6

prolonged use can cause what ?

Answer 6

melanonsis coli - reversible pigment of intestinal wall

Question 7

contraindications what may it induce

Answer 7

patients with intestinal obstruction may induce perforation
anal fissures and haemorrhoids

Question 8

what should be avoided in these patients

Answer 8

rectal preparations

Question 9

drug reactions

Answer 9

none clinically significant

Question 10

patient information for constipation

Answer 10

drinking plenty
fibre intake
need only afew doses before results are seen
dose can be adjusted
cramps and flatulence are normal - likely to get better over time

Question 11

what are the other laxatives ?

Answer 11

isphagula husk
lactulose
macrogol
phosplate enemas

Question 12

what is isphagula husk used for

Answer 12

constipation and faecal impaction where fibre cannot be increased
mild chronic diarrhoea associated with IBD/diverticular disease

Question 13

MOA

Answer 13

hydrophilic substance such as cellulose which cannot be absorbed or broken down
this attracts water into the stool and increases it mass
adequate fluid is therefore essential
increasing stool bulk -> peristalsis and aids relief of constipation

Question 14

adverse events

Answer 14

well tolerated - may cause abdominal distention
flatulence
GI obstruction -rarely

Question 15

warning/contraindications

Answer 15

not in patients with intestinal obstruction

faecal impaction

Question 16

drug interactions

Answer 16

no clinically significant adverse drug interactions

Question 17

PI

Answer 17

lots of water
acts as fibre supplement
dose can be adjusted

Question 18

indication of lactulose and macrogol

Answer 18

constipation
bowel prep prior to surgery/endoscopy
HE

Question 19

MOA

Answer 19

osmotically active substance
not digestions or absorbed and remain in gut lumen
hold water ijn the stool
stimulates peristalsis

Question 20

MOA in HE

Answer 20

reduces ammonia absorption by increasing gut transit rate

Question 21

SE of lactulose

Answer 21

cramping
farting
nausea
diarrhoea electrolyte disturbances

Question 22

warning

Answer 22

contraindicated in obstruction - risk of perforation

in caution with Heart failure and ascitres

Question 23

drug interactions

Answer 23

may increase warfarin effects

Question 24

doses

Answer 24

15ml x2 daily but 30-50ml in HE 3x a day

enema once daily

Question 25

which of the three causes nausea?

Answer 25

lactulose

Question 26

which should not be used in heart failure?

Answer 26

lactulose

Question 27

outline difference between 3

Answer 27

[1] increase in water and eleclytoe secretions from colonic musoca

[2] relies on non-digestable bulk- draws water in

(£) osmotlyitcal active substance not digested drawing water in

Question 28

which can be used for bowel prep?

Answer 28

lactulose

Question 29

which can cause melaonosis coli

Answer 29

senna

Question 30

which replaces fibre?

Answer 30

isphagula husk