GI Pharmacology Flashcards
What is 5-aminosalicyclic acid (5-ASA)
acts locally as an anti-inflammatory.
released in the colon and is not absorbed.
may inhibit prostaglandin synthesis
Sulphasalazine
a combination of ? and 5-ASA
sulphapyridine (a sulphonamide)
Sulphasalazine has few side effects due to the sulphapyridine moiety
FALSE
many side-effects are due to the sulphapyridine moiety
Sulphasalazine may cause which types of anaemia?
Heinz body anaemia, megaloblastic anaemia
Sulphasalazine sepcific side effects?
: rashes, oligospermia, headache
lung fibrosis
delayed release form of 5-ASA
Mesalazine
Aminosalicylates are associated with a variety of haematological adverse effects, including
agranulocytosis - FBC is a key investigation in an unwell patient taking them.
Mesalazine - sulphapyridine side-effects seen in patients taking sulphasalazine are avoided
mesalazine is still however associated with side-effects such as
GI upset, headache, agranulocytosis, pancreatitis*, interstitial nephritis
Olsalazine
two molecules of 5-ASA linked by a diazo bond, which is broken by colonic bacteria
true
pancreatitis is 7 times more common in patients taking ? than sulfasalazine
mesalazine
Antidiarrhoeal agents - Opioid agonists include
loperamide
diphenoxylate
Cholestyramine is
bile acid sequestrant used in the management of hyperlipidaemia.
Cholestyramine works by?
decreases bile acid reabsorption in the small intestine, therefore upregulating the amount of cholesterol that is converted to bile acid
Cholestyramine effect on lipid profile
reduce LDL cholesterol
Cholestyramine Adverse effects
abdominal cramps and constipation
decreases absorption of fat-soluble vitamins
cholesterol gallstones
may raise level of triglycerides
Metoclopramide is
D2 receptor antagonist* mainly used in the management of nausea.
Metoclopramide causes hyper/hypoprolactinaemia?
hyperprolactinaemia
Metoclopramide neuro s/e
extrapyramidal effects
tardive dyskinesia
parkinsonism
Metoclopramide should be avoided in
bowel obstruction, but may be helpful in paralytic ileus.
Metoclopramide it is also a mixed 5-HT3 receptor antagonist/5-HT4 receptor agonist
true
Proton pump inhibitors (PPI) work by?
rreversible blockade of H+/K+ ATPase of the gastric parietal cell.
Proton pump inhibitors (PPI) electrolyte disturbances?
hyponatraemia, hypomagnasaemia
Proton pump inhibitors (PPI) adverse effects?
osteoporosis → increased risk of fractures
microscopic colitis
increased risk of Clostridium difficile infections
Refeeding syndrome describes
metabolic abnormalities which occur on feeding a person following a period of starvation. It occurs when an extended period of catabolism ends abruptly with switching to carbohydrate metabolism
Refeeding syndrome metabolic consequences
hypophosphataemia
hypokalaemia
hypomagnesaemia
abnormal fluid balance
hypomagnesaemia may predispose to?
may predispose to torsades de pointes
Refeeding syndrome may avoided by identifying patients at a high-risk of developing refeeding syndrome:
Patients are considered high-risk if one or more of the following:
BMI < 16 kg/m2
unintentional weight loss >15% over 3-6 months
little nutritional intake > 10 days
hypokalaemia, hypophosphataemia or hypomagnesaemia prior to feeding (unless high)
Refeeding syndrome may avoided by identifying patients at a high-risk of developing refeeding syndrome:
Patients are considered high-risk if TWO or more of the following:
BMI < 18.5 kg/m2
unintentional weight loss > 10% over 3-6 months
little nutritional intake > 5 days
history of: alcohol abuse, drug therapy including insulin, chemotherapy, diuretics and antacids
NICE recommend that if a patient hasn’t eaten for > 5 days, aim to re-feed at no more than ?% of requirements for the first 2 days.
NICE recommend that if a patient hasn’t eaten for > 5 days, aim to re-feed at no more than 50% of requirements for the first 2 days.
