BNF Chapter 1: The GI System Flashcards
What are the two main classifications of antispasmodics?
Antimuscarinics
Smooth muscle relaxants
How do antimuscarinics work, and what drugs do they include?
Reduce intestinal motility and are used for gastro-intestinal smooth muscle spasm
Atropine sulfate, Dicycloverine hydrochloride, Propantheline bromide and hyoscine butylbromide
What are some examples of smooth muscle relaxant drugs?
Alverine citrate
Mebeverine hydrochloride
Peppermint oil
What is coeliac disease?
An autoimmune condition that is associated with chronic inflammation of the small intestine. Gluten activates an abnormal immune response in the intestinal mucosa, which can lead to malabsorption of nutrients.
What is the only effective treatment for coeliac disease?
Strict, life-long, gluten-free diet.
Which key nutrients are patients with coeliac disease at risk of malabsorption of?
Calcium
Vitamin D
They should NOT self-medicate OTC, need to discuss with a specialist.
When would new onset constipation require urgent investigation?
In patients over 50
Accompanying symptoms such as anaemia, abdominal pain, weight loss, blood in stool.
Non-Drug Treatment
-Increase dietary fibre, fluid intake and exercise
-Increase fibre intake gradually; fruits, vegetables and whole grains.
-Laxative abuse can lead to hypokalaemia
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What are the different types of laxatives?
Bulk-forming laxatives- fybogel (ispaghula husk)
Stimulant laxatives- bisacodyl
Faecal softeners- docusate sodium and glycerol suppositories
Osmotic laxatives- lactulose and macrogols
Management of Constipation
-Short-Term- start with a bulk-forming laxative, add or switch to an osmotic laxative if unsuccessful. Can add a stimulant laxative if no change.
-Opioid Induced- AVOID bulk-forming. Use an osmotic laxative and a stimulant laxative are recommended.
-Faecal impaction- high dose of oral macrogol.
-Chronic constipation- start with a bulk-forming laxative, add or change to an osmotic laxative if unsuccessful. Can add a stimulant laxative if no change.
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What laxatives should be used to treat short-term constipation?
-Bulk-forming initially, add or switch to an osmotic if no differnce. Stimulant can also be added.
Which laxatives are recommended for opioid-induced constipation?
Osmotic and stimulant
Constipation in Pregnancy and Breast-Feeding
-Fibre supplements
-Bulk-forming laxatives are first choice in pregnancy and BF if food supplementation fails. Lactulose can also be used.
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Constipation in Children
-Dietary modification AND laxative is first-line treatment.
-Macrogol is first-line, with dose adjustment according to symptoms and response.
-Stimulant laxative can be added or swapped to if response is inadequate, then lactulose or docusate can be added if still no response.
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What is crohn’s disease?
A chronic, inflammatory bowel disease that mainly affects the GI tract. Characterised by thickened areas of the GI wall with inflammation extending through all layers, deep ulceration and fissuring of the mucosa, and the presence of granulomas.
What are some potential complications of crohn’s disease?
Fistulae
Anaemia
Malnutrition
Colorectal and small bowel cancers
Delayed puberty
Drug Treatment for Acute Disease
-Corticosteroid (prednisolone or IV hydrocortisone) can be used to induce remission in patients with a first presentation or single exacerbation in 12-months.
-Budesonide can be used where a corticosteroid is CI,
Add on treatments include azathiprine or mercaptopurine if there are 2+ inflammatory exacerbations in a year. These drugs can also be used as monotherapy to maintain remission.
How long does acute diarrhoea last?
Less than 14 days
What is usually considered the standard treatment when rapid control of diarrhoea is required?
Loperamide hydrochloride
What is diverticulosis?
An asymptomatic condition characterised by the presence of diverticula (small pouches protruding from the walls of the large intestine).
What is diverticular disease?
Where diverticula are present with symptoms such as abdominal tenderness and/or mild, intermittent lower abdominal pain with constipation, diarrhoea, or occasional large rectal bleeds.
When would acute diverticulitis occur?
When diverticula suddenly become inflamed or infected.
Drug Treatment of Diverticular Disease
- Bulk-forming laxatives should be considered if dietary changes have not relieved constipation.
-Analgesia such as paracetamol, or antispasmodics for abdominal cramps. NSAIDs not recommended.
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What is dyspepsia?
A range of upper-GI symptoms, which are typically present for 4 or more weeks.
Symptoms include upper abdominal pain, heart burn, gastric reflux, bloating, nausea/vomiting.
Non-Drug Treatment of Dyspepsia
-Healthy eating
-Weight loss (if obese)
-Avoiding trigger foods
-Smaller meals
-Smoking cessation
-Reducing alcohol consumption
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What are some drugs that can cause dyspepsia?
-Alpha-blockers
-Anti-muscarinics
-Aspirin
-Benzodiazepines
-Beta-blockers
-Bisphosphonates
-Calcium-channel blockers
-Corticosteroids
-Nitrates
-NSAIDs
-Theophyllines
-TCAs
Lowest effective dose should be prescribed, and stopped if possible.
Drug Management of Dyspepsia
-Uninvestigated dyspepsia: PPI should be prescribed for 4 weeks and tested for H.Pylori infection- treat if positive.
-Functional dyspepsia: Test for H. Pylori and treat if positive. If negative, prescribe a PPI or H2-receptor antagonist for 4 weeks.
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What is acute diverticulitis?
Where small pouches protruding from the walls of the large intestine (diverticula) suddenly become inflamed and infected
Acute Diverticulitis Treatment
-Systemically unwell patients, or patients with comorbidities or are immunocompromised should be offered antibacterial therapy.
First-line Oral:
-Co-amoxiclav
-Penicillin allergy: cefalexin with metronidazole OR trimethoprim with metronidazole
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C.Difficile Infection Treatment
Oral:
-First line: Vancomycin
-Second line: Fidaxomicin
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What is gastro-oesophageal reflux disease (GORD)?
A chronic condition where there is reflux of gastric contents (particularly acid, bile and pepsin) back into the oesophagus, causing symptoms of heart burn and acid regurgitation
Drug Treatment of GORD
-Stop all drugs that may cause or exacerbate GORD, or at least use lowest-effective dose: alpha-blockers, anticholinergics, benzodiazepines, beta-blockers, bisphosphonates, CCBs, corticosteroids, NSAIDs, nitrates, theophyllines and TCAs.
-PPI can be used for 4-8 weeks in diagnosed GORD.
H.Pylori
-Main cause of peptic ulcer disease
Treated with triple therapy: PPI + two antibacterials:
-First-line, 7 day course: PPI + amoxicillin + clarithromycin or metronidazole
-If penicillin allergy, 7 day course: PPI + clarithromycin + metronidazole
What drugs can play a role in inflammatory bowel disease?
Azathioprine
Ciclosporin
Mercaptopurine
Methotrexate
What is irritable bowel syndrome?
A common, chronic, relapsing and often life-long condition- symptoms include abdominal pain, constipation, diarrhoea, mucus and bloating
Treatment of IBS
-Dietary and lifestyle changes- increased fibe, regular meals
-Antispasmodic drugs (alverine, mebeverine and peppermint oil) can be taken in addition to lifestyle changes.
-A laxative (not lactulose) can be used for constipation
-Diarrhoea can be relieved by loperamide.
What is peptic ulcer disease, and what are some symptoms?
Gastric or duodenal ulceration, which is a breach in the epithelium of the gastric or duodenal mucosa.
-Nausea, indigestion, heartburn, loss of appetite, weight loss and a bloated feeling
Management of Peptic Ulcer Disease
-Stop drugs that induce peptic ulcers: NSAIDs, aspirin, bisphosphonates. corticosteroids, potassium chloride, SSRIs and recreational drugs.
-Can use antacids short-term to control symptoms
-Determine if the patient is H. Pylori positive- need to eradicate if so
What is a stoma?
An artificial opening on the abdomen to divert flow of faeces or urine into an external pouch located outside the body. Can be temporary or permanent.
Colostomy and ileostomy are most common forms of stoma, but can also get a gastrostomy, jejunostomy, duodenostomy or caeocostomy.
Prescribing in Patients with Stoma
-Enteric-coated and MR preparations should be avoided- may be insufficient release of the active ingredient. Instead use preparations with quick dissolution and absorption (liquids, capsules, and uncoated or soluble tablets are typically okay).
-Opioid analgesics may cause constipation
What is ulcerative colitis?
A chronic inflammatory condition, characterised by diffuse mucosal inflammation: it has a relapsing-remitting pattern. Associated with significant morbidity.
Treatment of Acute Mild-Moderate Ulcerative Colitis
-Topical aminosalicylate is firs-line- if remission is not achieved within 4 weeks, add an oral aminosalicylate. If still inadequate, consider addition of a topical or oral corticosteroid for 4-8 weeks.
Maintenance therapy with an aminosalicylate is recommended for most patients- corticosteroid is not recommended.
What are examples of stimulant laxatives?
Glycerol
Senna
Bisacodyl
What are some examples of osmotic laxatives?
Lactulose
Macrogol
What are some examples of bulk-forming laxatives?
Methylcellulose
Isphagula husk
What are some examples of stool softener laxatives?
Docusate
Arachis oil
Loperamide
- Usual dose is 4mg, maximum 16mg per day
-Under 12s must see a GP before taking it
-Only packs of 6 if GSL
Sulfasalazine
-Treats UC and active Crohn’s
-Can cause yellow discolouration of body fluids
-Renal function should be monitored
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What does simeticone treat?
An antifoaming agent
Bought by parents to help babies with colic
Uncertain evidence of benefit
What is a standard pantoprazole dose?
40mg
What is first-line to induce remission in mild-moderate ulcerative colitis? What is second-line?
A topical aminosalicylate, e.g. mesalazine eneme (Salofalk foam enemas).
Add an oral aminosalicylate if this does not induce remission in 4 weeks.
These are the same options for maintaining remission
What should be done to induce remission in severe ulcerative colitis?
IV corticosteroids, and assess the likelihood that the patient will need surgery.
What is first-line to induce remission in Crohn’s disease for first presentation or the only inflammatory exacerbation in a 12-month period?
Monotherapy with a conventional glucocorticoid, such as prednisolone, IV hydrocortisone
What drug category, and examples, are used first-line to treat IBS?
Antispasmodics:
- Hyoscine
-Mebeverine
-Alverine
-Peppermint oil
Which laxative should be avoided in IBS?
Lactulose
Loperamide is first-line to stop diarrhoea in IBS.
True or False?
True
Laxative: Co-danthramer is a stimulant laxative used in terminally ill patients due to potential cardiogenicity.
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What are the standard dosing recommendations for glycerin suppositories in children?
1g prn
Which two laxatives are carcinogenic, and should therefore only be used in terminally ill patients?
Dantron
Co-danthramer
What is the onset of action length for lactulose?
24-48 hours- not best for acute constipation
Ispaghula husk can take a few days to work.
True or False?
True
When would be the time when naloxogol would be recommended to treat opioid induced constipation?
If no other options have worked
REMEMBER: Azathioprine, Mercaptopurine, Methotrexate and Sulfasalazine should not be used to induce remission in Crohn’s. Prednisolone is first choice, but _ can be used second-line.
Budesonide
TPMT levels must be assessed prior to which drug type?
‘Thioprine’ drugs, e.g. mercaptopurine, azathioprine
Aminosalicylate drugs can cause blood disorders. Report fever, sore throat, flu-like symptoms etc
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Maintaining Remission in Ulcerative Colitis
-Topical (rectal) aminosalicylate alone (daily or intermittent) OR
-Oral aminosalicylate plus a topical OR
-Oral amingosalicylate alone (not as effective)
Following a severe relapse or 2 or more exacerbations in a year:
-Oral azathioprine or _
Methotrexate is not recommended for the management of UC, unlike with Crohn’s.
Mercaptopurine
Why is the use of loperamide in ulcerative colitis contraindicated?
Can increase the risk of toxic megacolon.
(it is fine in Crohn’s)
Which laxative is indicated for use in hepatic encephalopathy?
Lactulose
What are some symptoms of Crohn’s disease?
Diarrhoea
Abdominal pain
Elevated C-reactive protein levels
Elevated erythromycin sedementation rate
What should be monitored with patients taking mesalazine?
Renal function should be monitored before starting mesalazine, at 3 months and then annually after that
What is the onset of action of senna tablets?
8-12 hours
