Gastro Flashcards
What are the common uses of spironolactone?
to treat ascites and oedema due to liver cirrhosis
to treat chronic heart failure
to treat primary hyperaldosteronism
What is the mechanism of action of spironolactone?
Aldosterone antagonist
- increases sodium and water excretion and increases potassium retention by acting on distal tubules
What are important adverse reactions of spironolactone?
hyperkalaemia
gynaecomastia
liver impairment
jaundice
What are the warning for spironolactone?
renal impairment, hyperkalaemia, Addison’s disease, pregnant or lactating
What are important interactions for spironolactone?
any K+ elevating drugs - ACE-i, ARBs, potassium supplements
What are indications for giving azathioprine?
to maintain remission in IBD
disease modifying drug in autoimmune e.g. RA
to prevent organ rejection
What is the mechanism of action of azathioprine?
stops DNA and RNA replication in lymphocytes
What are some warnings of azathioprine?
should not be prescribed in absent TPMT activity
caution in liver or renal impairment, pregnancy
caution in previous hypersensitivity reaction
What are some interactions of azathioprine?
+corticosteroids = increased risk of infection
not prescribed with xanthine oxidase inhibitors e.g. allopurinol
trimethoprim increases chance of leukopenia
azathioprine can reduce effect of warfarin
What are examples and indications of alginates and antacids?
gaviscon or peptac
GORD, dyspepsia
What is the mechanism of alignates and antacids?
antacids - buffer stomach acids
alignates - increase viscosity of stomach contents, which reduces reflux
What are some adverse reactions of alignates and antacids?
GI upset
What are some cautions of alignates and antacids?
in children, do not give with thickened foods
caution with renal failure
can worsen hypoglycaemia
What are some interactions with alignates and antacids?
can bind to other drugs and reduce absorption so give drugs 2 hours after (esp. antibiotics, ACE-i, bisphosphonates)
can increase excretion of aspirin and lithium
What are names of aminosalicylates and how do they work?
mesalazine, sulfasalazine
they have antiinflammatory and immunosuppressive effects