PPT - PUD, IBD, DIARRHOEA AND CONSTIPATION Flashcards
What is Hartmanns solution?
Aka compound sodium lactate
A resuscitation isotonic/crystalloid fluid that is compositionally similar to blood
It contains sodium chloride, potassium chloride, calcium chloride dehydrate and sodium lactate in 60% water
How do you manage uncomplicated PUD?
if Helicobacter pylori is negative then proton pump inhibitors (PPIs) should be given until the ulcer is healed
if Helicobacter pylori is positive then eradication therapy should be given
How quick do PPIs work?
2-3 days
Why are IV high dose PPIs given in PUD?
To prevent rebleeding
How do you manage H.pylori?
eradication may be achieved with a 7-day course of
a proton pump inhibitor + amoxicillin + (clarithromycin OR metronidazole)
if penicillin-allergic: a proton pump inhibitor + metronidazole + clarithromycin
What drugs do you give for H.pylori eradication?
PPI
Clarithromycin
Amoxicillin (or metronidazole if penicllin allergy)
Why does simvastatin interact with clarithromycin?
Clarithromycin is a strong inhibitor of CYP450-3A4 so concentration of simvastatin will increase, increasing the risk of myopathy
What should the pt avoid whilst taking metronidazole?
Alcohol - causes a Disulfiram-like reaction
(unpleasant SE such as nausea, vomiting hot flushes)
What are crystalloids? Give some examples
Water with added salts/glucose
E.g. 0.9% sodium chloride, 5% dextrose, hartmanns
What are colloids? Whats an example?
Fluids containing large molecules that stay in the intravascular space longer and help retain fluid in the intravascular space
E.g. human albumin solution
How do you manage actively bleeding PUD?
IV PPI
Endoscopic intervention
If this fails then surgery
What are the adverse effects of PPIs?
Hyponatraemia and hypomagnasaemia
Osteoporosis
Microscopic colitis
Increased risk of c.diff
What is a contraindication for statins?
Macrolides
Pregnancy
Whats an example of bulk-forminglaxative?
Isphaghula husk
Bran
Methyl cellulose
Sterculia
What are examples of osmotic laxatives?
Lactulose and macrogols
What are examples of stimulant laxatives?
Bisacodyl
Senna
(Co-danthrusate)
What are examples of faecal softeners?
Co-danthrusate
Docusate sodium (partially)
Glycerol suppositions
Enemas containing arachis oil
Liquid paraffin
Which laxatives are safe in pregnancy?
senna
Magnesium salts
Docusate
Which laxatives are only used ib terminally il and why?
Bisacodyl
Co-danthramer
Co-danthrusate
These are used for terminally ill with opioid induced constipation as they contain dantron which is carcinogenic
How do you manage opioid-induced constipation?
Stimulant laxatives
If these fail then you can use methylnaltrexone (peripheral opioid receptor antagonist)
When do you use lactulose?
Just in hepatic encephalopathy
How should you manage a pt with constipation caused by neurological disease
Faecal softener with regular enemas or rectal washouts
Outline the order of laxative choice for opioid-induced constipation?
Stimulant and osmotic
(DO NOT USE BULK FORMING)
Outline the order of laxative choice for chronic constipation?
Bulk forming with plenty of fluid
Osmotic laxative
Stimulant
Outline the order of laxative choice for chronic constipation caused by IBS?
Softener
Osmotic
Stimulant
Linaclotide (stop all other laxatives)
Outline the order of laxative choice for constipation in chronic frail/low mobility pt?
Softener
Stimulant
Osmotic
(DON’T USE BULK FORMING AS CAN CAUSE A BLOCKAGE)
What drug therapies are available for diarrhoea?
Codeine phosphate
Loperamide
Diphenoxylate
How long. Do bulk forming laxatives take to work?
72 hours
What are SE of bulk forming laxatives?
Can worsen flatulance, bloating and cramping
Intestinal obstruction if adequate fluid intake is not met
What SE can stimulant laxatives cause?
Often cause abdominal cramp
Why is lactulose good for hep;antic encephalopathy?
It produces an osmotic diarrhoea of low faecal pH, and discourages the proliferation of ammonia-producing organisms.
What are oral rehydration therapy options?
Di sodium hydrogen citrate with glucose
Potassium chloride and sodium chloride
Potassium chrlodie with sodium chloride
potassium chloride with rice powder
sodium chloride and sodium citrate
When should you avoid using loperamide?
In bloody or suspected inflammatory diarrhoea
Significant abdominal pain
Active UC
Whats the moa of loperamide?
Acts on my-opioid receptors on circular and longitudinal intestinal muscle = reduces propulsive peristalsis and increases intestinal transit time
It stimulates intestinal absorption of water and electrolytes by inhibiting calmodulin
Whats the moa of diphenoxylate
an opiate receptor agonists that stimulate mu receptors in GI to decrease the peristalsis and constrict the sphincters. Diphenoxylate has a direct effect on circular smooth muscle of the bowel, that conceivably results in segmentation and prolongation of gastrointestinal transit time
How can you manage pain in IBS?
Antispasmodic agents
Second line - low dose TCA
How can you manage constipation in IBS?
Laxatives (avoid lactulose as it increases bloating)
How can you manage diarrhoea in IBS?
Loperamide
What are examples of antispasmodic drugs used in IBS?
Alverine citrate
Mebeverine hydrochloride
Peppermint oil
How do you induce remission in mild-moderate UC?
Rectal aminosalicylates
If remission is not achieved within 4 weeks - add oral aminosalicylates
If remission is still not achieved add oral corticosteroid
How shoul you induce remission in severe colitis?
IV steroids first line
Consider adding IV Ciclosporin after 72 hours if no improvement
How do you maintain remission in mild-moderate UC?
Rectal aminosalicylates
Oral aminosalicylates + rectal aminosalicylates
Oral aminosalicylate may be used first in left-sided and extensive UC
How do you maintain remission in UC following a severe relapse or >=2 exacerbation in the past year?
oral azathioprine or oral mercaptopurine
What are examples of aminosalicylates?
Masala one
Olsalazine
Sulfasalazine
What are examples of corticosteroids used in UC?
Hydrocortisone
Prednisolone
Budenoside
What are examples of anti-TNF alpha antibodies cytokine modulators used in UC?
Adalimumab
Infliximab
What immunosuppressants are used in UC?
Azathioprine
Methotrexate
What antibiotics are used in UC?
Metronidazole
What monitoring is required for corticosteroids?
Assess for osteoporosis
Cushingoid features
Assess for hyperglycaemia, cataracts, glaucoma
What monitoring is required for aminosalicylates?
Mesalazine - U&E annually
Sulfasalazine - FBC & LFT every 3 months
What are common SE of aminosalicylates?
Headache
What are the SE of immunosuppressants e.g. azathioprine?
Increased susceptibility to sunburn
Increased risk of cervical abnormalities
Increased susceptibility to infections
Potentially increased risk of lymphoma
What monitoring is needed for methotrexate?
U&Es, FBC and LFT every 3 months
Whats the main concern with biological agents such as infliximab?
Increased susceptibility to infections including TB
Whats the moa of azathioprine?
A prodrug that is quickly converted to 6-mercaptopurine this is then metabolised in the liver and gut to 6-thioguanine nucleotides = affects DNA in rapidly replicating cells = immunosuppression
What are 2 serious drug interactions with azathioprine?
Allopurinol
Febuxostat
(They slow the elimination of 6-MP by inhibiting xanthine oxidase)
What should be checked before starting azathioprine?
TPMT levels - this enzyme usually breaks down 6-mercaptopurine but this gene is subject to genetic polymorphism = some people dont have TPMT activity so azathioprine isnt broken down /cleared properly
What is infliximab?
A chimeric monoclonal antibody which has a high specificity for and affinity to TNF alpha
This neutralises the biological activity of TNF alpha by antagonising its receptors
It can also stimulate apoptosis of activates lymphocytes in gut mucosa
What are the side effects of azathioprine?
Bone marrow suppression
Pancreatitis
Increased risk of infection
Leucopenia
What is sulphasalazine?
A combination of a sulphonamide and 5-ASA
What is mesalazine?
A delayed release form of 5-ASA
Whats the benefit of mesalazine?
It avoids the sulphapyridine side effects you get in taking sulphasalazine
What are common side effects of all aminosalicylates?
GI upset
Headache
Agranulocytosis
Pancreatitis (7 times more common)
Interstitial nephritis
What are the sulphapyridine side effects you get with sulphasalazine?
Rashes
Oligospermia
Headache
Heinz body anaemia
Megaloblastic anaemia
Lung fibrosis
How do you induced remission in Crohn’s?
Glucocorticoids
Second line - 5ASA drugs
How do you manage refractory crohns or fistulating crohns?
Induce remission - Infliximab
Maintenance - azathioprine or methotrexate
How do you maintain remission in crohns?
Azathioprine or mercaptopurine
(Second line - methotrexate)
What proportion of crohns pt will end up getting surgery?
80%
What are the issues with empiric antibiotic therapy for acute infective diarrhoea?
Potential side effects
Most causes in UK caused by viruses
ProMotion of bacterial resistance
Eradication of normal flora
Excess cost
Most cases are self-limiting
Who may recieve empiric antibiotic for infective diarrhoea?
If severe disease e.g. >6 stools a day, volume depletion warranting hopsital
Features suggestive of invasive bacterial infection e.g. blood/mucous stools
Host factors that increase risk of complications e.g. >70 or immunocompromised
Which antibiotics are used for first episode of c.diff?
Oral vancomycin for 10 days
What are the risk factors of c.diff infections?
Second and third generation cephalosporins
Clindamycin
Fluoroquinolone
Broad spectrum penicillins
PPI
>65
Prolonged hospitalisation
Exposure to others with c.diff
Previous history of c.diff
Which antibiotics are used for recurrent episodes of c.diff?
If within 12 weeks of symptoms resolution - oral fidaxomicin
If >12 weeks of symptom resolution - oral fidaxomicin or oral vancomycin
Which antibiotics are used for life-threatening of c.diff?
Oral vancomycin and IV metronidazole
