gastrointestinal system Flashcards
Dyspepsia signs n symptoms
Nausea
abdominal pain
bloating
acid reflux
vomiting
loss of appetite
heartburn regurgitation
serious dyspepsia symptoms
ALARM
Anaemia
loss of weight
anorexia
recent onset of progressive symptoms
melena, dysphagia, hematemesis
may require referral for upper GI endoscopy.
mucosal protectant
example moa counselling point
Drug: Misoprostol
Mechanism: Inhibits gastric acid secretion by stimulating prostaglandin E1 receptors on parietal cells, reducing acid production.
Counselling: Can cause uterine contractions, commonly used for pregnancy termination.
H2 receptor antagonists
example, moa, counselling
Drug: H2RAs (e.g., Ranitidine, Famotidine)
Mechanism: Block histamine H2 receptors on parietal cells, inhibiting the secretion of stomach acid.
Counselling: Take as directed.
May cause dizziness or drowsiness. Use cautiously in patients with liver or kidney disease.
PPIs
example, moa, counselling
Drug: e.g., Omeprazole, Lansoprazole
Mechanism: Inhibit the proton pump (H+/K+ ATPase) in the stomach lining, effectively reducing the production of gastric acid for long-term relief.
Counselling: Take 30 minutes before meals. Long-term use may increase the risk of fractures, vitamin B12 deficiency, and hypomagnesaemia.
Alginates
example
Gaviscon
Mechanism: Form a gel-like barrier on top of stomach contents, preventing acid reflux into the oesophagus, providing relief from heartburn.
counselling: take after meals
avoid lying down after taking
bloating, flatulence
Non-pharmacological advice for GI tract conditions (UC, GORD, chrons, IBS)
- wight loss
- avoid datty foods
- eat smaller meals regularly
- extra pillow hen sleeping
- avoid choco, mint, alch, coffee
- avoid spicy food
GORD
reflux of gastric acid contents into oesophagus causing heart burn and acid regurgitation
cause: weakened gullet
GORD complications
- oesophagitis
- ulcers
- haemorrhage
- stricture formation
- anaemia
- aspiration pneumonia
- Barret’s oesophagus- erosion of oesophagus, and causes metaplasia.
sings and symptoms of Barret’s oesophagus
- frequent heart burn
- dysphagia
- vomiting blood
- stomach pain
- weight loss as eating is painful.
2 types of hiatus hernia
1) sliding
2) rolling
h pylori diagnosis test
carbon-13 urea breath test
upper endoscopy
Pharmalogical treatment of peptic ulcer disease (h pylori)
first line: triple therapy of
PPI + amoxicillin + clarithromycin/metronidazole
for 1 week
NSAID induced peptic ulcer treatment
stop nsaid
PPI at highest dose (8weeks) then reduce after review
or if nsaid treatment continue:
treat with ppi as normal
treat with ppi and on healing witch to misoprostol
treat with PPI and swtich NSAID to COX-2 inhibitor (celecoxib, etoricoxib)
examples of antiflautulents
simethicone
pepper mint oil
examples of antispasmodics
Anticholinergic drugs (atropine-like) e.g. hyoscine butylbromide, dicloverine
* Direct-acting smooth muscle relaxants e.g. Mebeverine, alverine and peppermint oil
constipation causes
laack of excercise
low fibre diet, dehydration
drug induced: antacids, antihistamines, opioids etc
Laxatives 5 types
1) bulking: ispaghula husk
- moa: stimulate mucosal receptors, causing peristalsis.
- counselling: increase fluid intake
2) osmotic: lactulose
- moa: retains fluid in the bowel, changing water distribution in the faeces, producing a softer stool
counselling: not used in HF patients, can cause imbalance of electrolytes.
3) stimulant: senna
- moa: stimulates colonic nerves causing increased intestinal motility and movement of stool.
counselling: bedtime dose preferred. can cause abdominal cramps.
4) softeners: docusate
moa: reduces surface tension of stool, intestinal fluid can then penetrate stool easier.
counselling: usually used as a combo with stimulant laxative.
5) selective serotonin 5HT4- receptor agonist: Prucalopride
counselling:
cautious in patients with history of arrthymias, or ischaemic heart disease.
- dizziness and fatigue may
initially affect a patient’s ability to drive or operate
machinery
serious diarrhoea symptoms
constipation alternating with diarrhoea
blood in stool
high fever, abdominal pain, vomit
weight loss
dehydration (moderate-severe)
faecal incontinence
3 grades of dehydration
mild: body weight reduced by less than 4%, thirst, reduced urine output, dry mucus membranes, mild tachycardia
moderate: body weight reduced by 4-6%. sunken eyes, abnormal respiratory pattern, reduced skin turgor
severe: reduced body weight by 7% or more, no ability to drink, lack of consciousness.
general diarrhoea treatment
generally, staying hydrated and oral rehydration salts, loperamide (anti-motility), emptying bowels when appropriate.
antibiotic choice for treating diarrhoea based on infection
campylobacter enteritis: erythromycin
acute giardiasis and amoebiasis: metronidazole
clostridium difficile: 1st line: vancomycin (in addition to metronidazole if severe)
2nd line: fidaxomicin
toxic megacolon: metronid/vanco
salmonella: amoxicillin, chloramphenicol
shigellosis: norfloxacin, amoxicillin
cholera: doxycycline, amoxicillin
what laxative is used in IBS
linaclotide
used first and second line treatment for constipation no work
its is a black triangle drug
for IBS-C
what is first line treatment IBS
antispasmodics: meberverine hydrochloride, pepper mint oil.
loperamide
laxatives
second line: TCAs: amitriptyline, nortriptyline
c.difficile symptoms
mild diarrhoea
abdominal cramps
abdominal distension
fever
sepsis
c difficile diagnosis
type 7 stool
toxin enzyme immunoassays
toxin gene
glutamate dehydrogenase
true or false smoking cessation can trigger flare up in UC
yah
5 classifications of UC
1) proctitis: rectum only
2) proctosigmoiditis: rectum + sigmoid colon
3) distal colitis: left side of colon only
4) pancolitis: entire colon
5) backwash ileitis: distal ileum
UC symptoms
bloody diarrhoea
faecal urgency
abdominal pain
fatigue, weight loss
tachycardia
tenesmus
what causes gall stones and kidney stones in CD
malabsorption of fat and bile salts
gall stones: due to increased cholesterol levels in bile
kidney stones: due to unabsorbed long chained fatty acids.
common symptoms of Chrons
1) anaemia
2) electrolyte imbalance
3) weight loss
4) stricture, fistulas, fissures
5) dysphagia, nausea and vomit.
6) abdominal pain, diarrhoea, nocturnal diarrhoea
IBD complications
intestinal complications: strictures, fissures, fistulas
rectal abscesses
toxic megacolon
malignancy
haemorrhoids
non-intestinal complications: Osteoporosis, arthritis, anaemia
gall stones
iritis and episcleritis
skin complications
first and second line drugs for UC and CD
UC
first: amino salicylates (sulfasalazine, mesalamine)
topical (mesalamine) (enema, suppositories)
second: corticosteroids, thiopurines, TNF inhibitor
CD:
first: amino salicylates
corticosteroids (prednisone, budesonide)
second: thiopurines (Azathioprine)
TNF inhibitors, surgery
methotrexate
amino salicylates
sulfasalazine, mesalazine
cautions:
in renal/hepatic impairment, or in blood disorders (anaemia etc).
side effects:
nausea, vomit, abdominal pain, headache, rash, hepatotoxicity
monitoring:
- LFTs every 2-4 weeks initially, then every 3 months.
- creatine, urinalysis, FBC
counselling:
- take with food
- look out for signs such as usual bleeding, bruising, fatigue.
- drink fluid to prevent kidney stones
- yellow orange urine/skin discolouration.
corticosteroids
Prednisolone, prednisone
cautions: HTN, diabetes, osteoporosis, GI disorders, in fungal infections.
side effects: weight gain, HTN, hyperglycaemia, OP, increased appetite, insomnia.
monitoring: BP, BG, BD, electrolytes and liver function.
counselling: take in morning, maintain calcium C and D intake.
Thiopurines
azathioprine, mercaptopurine
cautions: hypersensitivity
side effects: bone marrow suppression, nausea, hepatotoxicity, increased infection risk
monitoring: FBC, LFT, TMPT test
counselling: take with food, avoid live vaccines.
types of anti emetics
1) Serotonin (5-HT3) Antagonists
Ondansetron, Granisetron, Dolasetron, Palonosetron
2) Dopamine Antagonists
Metoclopramide, Prochlorperazine, Domperidone, Haloperidol
3) Antihistamines (H1 Antagonists)
Dimenhydrinate, Meclizine, Cyclizine, Diphenhydramine
4) Anticholinergics
Scopolamine
5) Corticosteroids
Dexamethasone, Methylprednisolone
6) NK1 Receptor Antagonists
Aprepitant, Fosaprepitant, Rolapitant, Netupitant
7) Cannabinoids
Dronabinol, Nabilone
8) Benzodiazepines
Lorazepam, Diazepam, Alprazolam
dopamine antagonists
Examples: Metoclopramide, Domperidone, Chlorpromazine, Prochlorperazine, Droperidol
Indications: Nausea & vomiting (N+V) due to reduced gut motility, chemotherapy, post-op, vertigo
Mechanism: Block D2 receptors in the brain and gut, promoting prokinetic effects
Adverse Effects: Diarrhea, fatigue, restlessness, extrapyramidal symptoms (metoclopramide), hyperprolactinemia
Notes: Avoid in GI obstruction; metoclopramide may cause movement disorders, especially in younger patients.
serotonin 5-HT3 receptor antagonists
Examples:
Ondansetron, Granisetron, Palonosetron
Indications:
Chemotherapy-induced N+V (CINV), radiation-induced N+V (RINV)
Mechanism of Action:
block 5-HT3 receptors in the chemoreceptor trigger zone (CTZ) in the vagus nerve in the GI tract.
Adverse Effects:
GI issues (constipation/diarrhea), headache, dizziness
Notes:
Often combined with corticosteroids (e.g., dexamethasone); linked to QT prolongation.
H1 Receptor Antagonists
Examples:
Cyclizine, Cinnarizine, Promethazine, Diphenhydramine
Indications:
Motion sickness, vertigo, postoperative N+V
Mechanism of Action:
Block histamine and acetylcholine pathways in vestibular system
Adverse Effects:
Drowsiness, dry mouth, constipation, tachycardia (IV)
Notes:
Avoid in patients with anticholinergic issues (e.g., BPH); caution with sedatives.
NK1 (neurokinin-1 ) Receptor Antagonists
Examples:
Aprepitant, Fosaprepitant
Indications:
Acute and delayed CINV
Mechanism of Action:
Block Substance P at NK1 receptors in the CTZ
Adverse Effects:
Fatigue, constipation, neutropenia, liver enzyme elevation
Notes:
Often combined with 5-HT3 antagonists or dexamethasone; CYP3A4 inhibitor, watch for drug interactions.
