Gastro-intestinal system Flashcards
‘Ulcerative colitis increases your chances of developing venous thromboembolism and colorectal Ca’
True or False?
True
Name some aminosalicylates
Mesalazine, sulfasalazine, olsalazine, balsalazide
Why should mesalazine be prescribed by brand?
Oral preparations may have different delivery characteristics
How is a flare of UC usually treated?
- Topical/oral aminosalicylate
- Oral prednisolone
- Tacrolimus or budesonide multimatrix
How is diarrhoea in UC treated?
With loperamide/codeine during remission
This is CONTRA-INDICATED during active UC as there is a risk of toxic megacolon
What is usual maintenance treatment for Crohns disease?
- No treatment, patients must be aware of signs of relapse
OR - Azathioprine/mercaptorine monotherapy
- Methotrexate
Do not offer a steroid for maintenance treatment
Can loperamide/codeine be used to manage diarrhoea in Crohns?
Yes- if no colitis
What abx are used to treat fistulating Crohns?
Metronidazole/ ciprofloxacin
What lifestyle factors can reduce the risk of relapse in Crohns?
- Smoking cessation
- High fibre diet
What is first line treatment for an acute flare of Crohns?
Corticosteroids
Prednisolone, methylpred or IV hydrocortisone
How should patients on aminosalicylates be counselled?
Risk of blood disorders/dyscrasia
Report any unexplained bleeding, bruising, sore throat etc
What monitoring is required for patients on aminosalicylates?
- FBC if signs of blood disorders
- Renal function, risk of neprotoxicity
Why should aminosalicylates be avoided during breast feeding?
Risk of diarrhoea in the newborn
Which aminosalicylate can turn bodily fluids including contact lenses orange?
Sulfasalazine
Why should mesalazine not be given with lactulose?
Lactulose lowers pH of stools, can prevent sufficient release of MR/EC preparations of mesalazine
Which lifestyle advice can be offered to patients suffering with IBS?
- Increase exercise
- Eat regular meals
- Limit fresh fruit to 3 portions per day
- Increase fibre and fluid intake
- Reduce caffeine, alcohol and fizzy drinks
Why should lactulose not be recommended in IBS?
Can cause bloating
How does NICE define constipation?
Defecation less than 3 times per week
Differs for each person
Which ‘red flags’ would ean you referred a patient presenting with constipation?
- New onset constipation aged over 50
- Anaemia
- Abdo pain/vomiting/bloating
- Unintentional weight loss
- Blood/mucus in stools
- Painful defecation
- Secondary caused by drug, drug should be reviewed
Which patient would you NOT refer?
- Woman in her late 50s presenting with 3 weeks of constipation and this is the first time she has had these symptoms
- Man aged 23 with new constipation after being prescribed co-drydamol for an injury
- Man aged 47 with constipation and a 2 month history of weight loss
- Woman aged 75 with a 3 day history of constipation and she has bought lactulose for this in the past
- Woman aged 60 with constipation, abdominal pain and blood in stools
Woman aged 75 with a 3 day history of constipation and she has bought lactulose for this in the past - if no new/unusual bowel habits or other red flags
What is a sign of laxative abuse?
Hypokalaemia
What is the recommended first line treatment for constipation?
Bulk-forming laxatives
Name some bulk-forming laxatives?
Ispaghula husk, methylcellulose (also softener), sterculia
How long do bulk-forming laxatives take to work?
72 hours
What patient counsellign should be given with bulk-forming laxatives?
- Ensure adequate fluid intake
- Don’t take before bed to avoid obstruction
What laxative is recommended for pregnant women?
bulk-forming laxatives
Name some stimulant laxatives?
Bisacodyl, sodium picosulfate, senna, co-danthramer, co-danthrusate, docusate, glycerol suppositories
How long do stimulant laxatives take to work?
6-12 hours, take before bed for an effect the following morning
Suppositories take 15-30 mins
What can be caused by excess use of stimulant laxatives?
- lazy bowel
- diarrhoea
- hypokalaemia
- cramps
Which stimulant laxative also works as a faecal softener?
Docusate
How long should stimulant laxatives usually be used for?
Approx 7 days
Which stimulant laxatives should only be used in terminally ill patients?
Co-danthramer and co-danthrusate - potential carcinogens
Name some osmotic laxatives?
Macrogol 3350, lactulose, magnesium hydroxide
Why is lactulose also useful in hepatic encephalopathy?
Lowers faecal PH and stops proliferation of ammonia-producing bacteria
Which laxatives can be used for chronic constipation that is unresponsive to other laxatives for at least 6 - 12 months?
- Linaclotide (in IBS)
- Lubirprostone
- Prucalopride
How should opioid-induced constipation be treated?
- Osmotic laxative WITH stimulant laxative
- Naloxegol
- Methylnaltrexone
AVOID bulk-forming as can cause obstruction
Why should senna not be recommended in the third trimester / near term?
Can stimulate uterine contractions
First line for constipation in children?
Macrogol with diet/behaviour intervention
What are some ‘red-flags’ when to refer in diarrhoea?
- Unexplained weight loss
- Rectal bleeding
- Persistent diarrhoea
- Systemic illness
- Recent hospital treatment/abx
- Recent foreign travel
- Signs of dehydration
When would you refer these patients with diarrhoea?
- Baby under 1
- Elderly patient over 90
- Adult
- Child under 3
- Child aged 12
- Baby under 1 - over 1 day
- Elderly - over 2 days
- Adult - over 3 days
- Child under 3 - over 2 days
- Child aged 12 - over 3 days
What age can you sell loperamide OTC?
12 plus
For diagnosed IBS over 18s only
What is the maximum dose of loperamide?
16mg
What is the MHRA warning associated with loperamide?
- Risk of cardiac adverse reactions at high doses
- Can cause QT prolongation, torsades de point, cardiac arrest
- Remind patients not to take over recommended dose
How can loperamide overdose be reversed?
Naloxone - acts on opioid receptors in GI tract
What antibiotic is occasionally given as prophylaxis for travellers diarrhoea?
Ciprofloxacin
Contra-indications for loperamide?
- Active UC
- Antibiotic associated colitis
‘Red flags’ that mean an urgent endoscopic referral is needed in acid reflux/dyspepsia?
A - Anaemia L - Loss of weight A - Anorexia R - Recently changes symptoms/new symptoms if >55 M - Malaena, dysphagia, heamotemesis
What are the 2 main causes of peptic ulcer?
NSAIDs + H. pylori
What is the treatment for H. Pylori?
Twice daily PPI + Clarithromycin + Amoxicillin OR metronidazole for one week
How long should PPI therapy be given for H. Pylori?
Usually just for one week
Can be given for 4 weeks if ulcer is large or complicated (eg, haemorrhage)
How is H. Pylori tested for?
C-Urea breath test
Which patients are at high risk for developing an NSAID-associated ulcer?
- Over 65s
- History of peptic ulcers/GI complications
- Other meds with GI side effects
- Those with serious co-morbidities
What is sucralfate used for and what is the associated risk?
Prophylaxis of gastric ulceration
Risk of bezoar formation esp, in seriously ill patients
Name some H2 receptor antagonists?
Ranitidine, cimetidine, nizatidine, famotidine
Caution to remember with H2 antagonists?
Can mask the symptoms of gastric cancer
If patients have alarm features then must rule out malignancy
What side effect is associated with H2 antagonists?
Psychiatric reactions - confusion, depression, dizziness and hallucinations esp in the elderly
GI side effects - nausea, diarrhoea, constipation
Erectile dysfunciton
Tachycardia
Who can buy ranitidine OTC?
- Over 16s
- Max 2 weeks treatment
- 75mg per dose/ max daily dose 300mg
Which H2 receptor antagonist is considered safest in pregnancy?
Ranitidine
What is misoprostol used for?
Treatment/prophylaxis of ulcer
Why should misoprostol be avoided in pregnancy?
Teratogenic
Can induce uterine contractions and is associated with abortion
How do PPIs work?
Inhibit gastric acid secretion by blocking the ‘proton pump’ of the gastric parietal cell
‘PPIs are associated with a low risk of subacute cutaneous lupus eythematosus’
True or false?
True - If a patient develops lesions consider this diagnosis and advise them to keep skin protected from sunlight
3 cautions with PPIs?
- Mask symptoms of gastric Ca
- Risk of osteoporosis/fractures, advise patients to have adequate calcium and vitamin D intake
- Can increase the risk of GI infections including C. Diff
What monitoring is required with PPIs?
- Serum magnesium - risk of hypomagnesaemia and more common if over 1 year of treatment.
- Sodium - can cause hyponatraemia
Why should a patient taking omeprazole + digoxin be monitored?
PPIs can cause hypomagnesaemia
Low magnesium increases the risk of digoxin toxicity
Important interactions with omeprazole?
- Methotrexate - omeprazole is an enzyme inhibitor and can decrease methotrexate clearance
- Clopidogrel - omeprazole can decrease the anti-platelet effect
Which PPIs can be sold OTC?
Esomeprazole (nexium) 20mg - GSL
Omeprazole 10mg - maximum treatment 20mg OD for 4 weeks
Pantoprazole 20mg OD for 4 weeks
Can only be sold to 18+
Which drugs can interact with antacids so must be taken after a 2 hour gap?
- Tetracyclines
- Quinolones
- Bisphosphonates
Antacids can impair absorption
‘Antacids can lower gastric PH’
True or false?
False - they increase gastric pH and therefore can damage medicines with enteric coating
In what conditions should antacids with high sodium content be used with caution?
- Hypertension
- Heart, liver and kidney failure
- Patients on lithium - monitor levels
What are anti-muscarinic side effects?
Fight/fight
Can’t see, can’t wee, can’t shit, can’t spit
Also tachycardia, pupils dilate, confusion (elderly)
Which antimuscarinics can be used to treat gastro-intestinal spasm?
Hyoscine butylbromide
Dicycloverine
Propantheline
When are anti-muscarinics contraindicated?
- Enlarged prostate/urinary retention
- GI obstruction
- Myasthenia gravis
- Glaucoma
What is the MHRA warning associated with hyoscine butylbromide?
Risk of serious adverse effects in patients with underlying cardiac disease
Can cause tachycardia, hypotension + anaphylaxis
When can you sell buscopan (hyoscine butylbromide) OTC?
- Over 6s
- Medically confirmed IBS
- Max single dose 20mg
Which BMI is classed as obese?
Over 30
When can orlistat be sold OTC?
- Over 18s
- P medicine
- Treatment can only be continued past 12 weeks if 5% reduction in body weight
Which vitamins can orlistat impair the absorption of?
Fat soluble
D, E, A, K
‘Olistat may decrease the plasma concs of some drugs’
True or false?
True - eg, anticoagulants, amiodarone, ciclosporin
What advice should be given to patients receiving Creon (pancreatin)?
- Take with meals and snacks as inactivated by gastric acid
- Inactivated by heat, don’t take with hot food/drinks
- Ensure adequate hydration
- Avoid reduced fat diets and food that is hard to digest
