Laxatives

Question 1

Laxative license in IBS

Answer 1

Linaclotide

Question 2

Laxative first line in preg if dietary and lifestyle aren’t sufficient

Answer 2

Bulk forming - eg ispagula husk

Question 3

Useful definition of constipation

Answer 3

Passage of hard stools less frequently that the patient’s own normal pattern

Question 4

What electrolyte imbalance can result from laxative abuse

Answer 4

Hypokalaemia

Question 5

The 4 main classes of laxatives

Answer 5

Bulk forming
Softening
Stimulant
Osmotic

Question 6

Counselling for bulk forming laxatives

Answer 6

Adequate fluid intake must be maintained to avoid intestinal obstruction

Question 7

What is an effective bulk forming preparation that I can’t find in the BNF?

Answer 7

Unprocessed wheat bran taken with food or fruit juice

Question 8

What type of laxative is ispagula

Answer 8

Bulk forming

Question 9

What type of laxative is methycellulose

Answer 9

Bulk forming and faecal softener

Question 10

Name some bulk forming laxatives

Answer 10

Ispagula
Methycellulose
Stercula

Question 11

Powerful laxatives like cascara and castor oil are obsolete but what sort of laxatives are they

Answer 11

Stimulant

Question 12

What sort of laxative is docusate

Answer 12

Stimulant and softener

Question 13

What sort of laxative is Senna

Answer 13

Stimulant

Question 14

What sort of laxative is bisocodyl

Answer 14

Stimulant

Question 15

What type of laxative is picosulfate

Answer 15

Stimulant

Question 16

What sort of laxatives are co-danthramer and co-danthrusate

When can we use them

Answer 16

Stimulant

Palliative care - carcinogenic and genotoxic

Question 17

What is the actin of glycerol suppositories

Answer 17

Lubricant and mild irritant ( in the stimulant section )

Question 18

Disadvantage of stimulant laxatives

When to avoid

Answer 18

Often cause abdocramp

Avoid in obstruction

Question 19

What can excessive use of stimulant laxatives lead to (2)

Answer 19

Diarrhoea and hypokalaemia

Question 20

Why should we avoid unstandardised preparations of cascara, frangula, rhubarb and Senna?

Answer 20

Action is unpredictable

Question 21

Why should we avoid aloes, jalap, colocyth

Answer 21

DRASTIC PURGATIVE ACTION

Question 22

Parasympathomemeitcs are rarely used for their GI action as stimulants… Some examples of these include

Answer 22

Bethanechol
Neostigmine
Pyridostigmine

Question 23

Softener are useful in what conditions according to the BNF

Answer 23

Haemorrhoids

Anal fissure

Question 24

Liquid paraffin is what sort of laxative and what is the disadvantage

Answer 24

Softening

Leakageeeeeeeee

Question 25

how do osmotic laxatives work?

Answer 25

increase the amount of water in the large bowel by drawing in fluid or retaining the fluid they were administered with

Question 26

lactulose is what sort of laxative | what is it also used for? how does this work

Answer 26

osmotic - synthetic disacharide that is not absorbed from the GI - producing osmotic diarrhoea of low faecal pH thus discouraging ammonia producing organisms (treat hepatic encephalopathy)

Question 27

macrogols are what sort of laxative

Answer 27

osmotic

Question 28

what is the disadvantage of osmotic laxatives

Answer 28

dehydration - giving with fluid my reduce this

Question 29

why should sodium salts be avoided as a laxative? | what is the mode of action here anyway?

Answer 29

sodium and water retention (osmotic laxative)

Question 30

what type of laxative is magnesium salts | when is this used?

Answer 30

osmotic - often abused but ok for occasional use

Question 31

phosphate enemas are what sort of laxative? | when are they used?

Answer 31

osmotic | surgery

Question 32

what is licaclotide mode of action | what do we treat with it?

Answer 32

guanylate cyclase C receptor agonist that is used for IBS associated with constipation it increases intestinal fluid secretion and transit and decreases viceral pain (it's metabolised in the GI and therefore virtually undetectable in the plasma)

Question 33

what is lubipristone for? | mode of action?

Answer 33

chloride channel activator | idiopathic constipation that doesn't respond adequately to lifestlye chages

Question 34

what is prucalopride for? | mode of action?

Answer 34

treatment of chronic constipation in woment where other laxatives have failed selective seritonin 5HT4 receptor agnonist with prokinetic properties

Question 35

steps for constipation treatment in preg

Answer 35

-dietary and lifestyle 1st - bulk forming e.g. ispagula 2nd - osmotic e.g. lactulose 3rd - stimulant e.g. bisocodyl/ senna

Question 36

how many days without passing stools should be a concern in children

Answer 36

3

Question 37

should you sell laxatives for children

Answer 37

no - should be managed by a specilist

Question 38

in infants what home type remedy could you use for constipation?

Answer 38

increased intake of fluids - particularly juice containing sorbitol (prune, pear or apple) may be sufficient

Question 39

what laxatives are suitable for infants under 1 year

Answer 39

lactulose | oral prep containing macrogols or glycerol supositories can be used for faecal impaction

Question 40

what is the treatment of constipation for children over 1 year

Answer 40

``` review of diet then macrogol then lactulose then stimulant ```

Question 41

treatment of faecal impaction may initially ...

Answer 41

increase symptoms of soiling and abdo pain | use macrogols and if this doesnt work in two weeks use a stumulant

Question 42

when in the day should ispagula husk be had

Answer 42

not before bed | with plenty of fluid

Question 43

how should methycellulose be taken when being used for ostomy control

Answer 43

avoid fluid intake for 30 mins before admin

Question 44

what is a selective opioid antagonist used for opiod induced constipation

Answer 44

methylnaltrexone bromide (subcutaneous)

Question 45

how long does lactulose take to act

Answer 45

about 48 hours

Question 46

`codanthomer cautions

Answer 46

avoid prolonged exposure to skin | only for palliative care

Question 47

what colour can codanthromer change your urine

Answer 47

red

Question 48

senna is licensed from what age

Answer 48

2 years

Question 49

what time of day is senna usually taken

Answer 49

at night

Question 50

when in the day should sterculia be taken

Answer 50

NOT before going to bed - preparations that swell in contact with water shouldnt be then then

Question 51

how does loperamide work? who is it suitable for

Answer 51

opioid receptors in the gut but doesnt cross the BBB antimotility suitable for adults ONLY

Question 52

why dont we use antibiotics for diahorreah in the UK

Answer 52

usually a viral cuase

Question 53

what antibiotic might be given for prophylaxis of travelers diarrhoea - but prophylaxis is not usually recommended

Answer 53

cipro

Question 54

when can bulk forming laxative be used for diarrhoea?

Answer 54

ispagula etc are used for diarrhoea associated with diverticuar disease

Question 55

how does racecadotril work?

Answer 55

used for dihorreah, inhibits the breakdown of endogenous opioids thus increasing opioid stimulation in the GI

Question 56

age at which you can sell loperamide OTC

Answer 56

18