GI drugs

Question 1

What is the mechanism of PPI?

Answer 1

Inhibit gastric acid secretion by blocking proton pump of gastric parietal cells.

Question 2

What is omeprazole used for?

Answer 2

GORD, peptic ulcer disease, dyspepsia (indigestion), H. pylori infection

Question 3

Common side effects of PPI?

Answer 3

Abdominal pain, dizziness, dry mouth.

Question 4

What are the cautions of using PPI?

Answer 4

PPIS can mask symptoms of gastric cancer, long term use in the elderly can increase risk of fractures. (Patients at risk of osteoporosis should maintain intake of calcium and vitamin D)

Question 5

What are the different types of laxatives?

Answer 5

Osmotic laxatives - draw fluid out tissues and into colonic lumen.

Stimulatory laxatives - stimulate colon to contract more

Bulk forming laxatives - attracts water into stool to bulk it to stimulate peristalsis

Question 6

What is ispaghula husk (fybogel) and methylcellulose an example of and used for what?

Answer 6

Bulk forming laxative for constipation and faecal impaction.

Question 7

What laxative would you use to manage hepatic encephalopathy?

Answer 7

Osmotic laxative e.g. lactulose

Question 8

What is phosphate enema and lactulose an example of?

Answer 8

Osmotic laxative used for hepatic encephalopathy, constipation and faecal impaction.

Question 9

What is senna and bisacodyl a example of and used for what?

Answer 9

Stimulant laxative used for constipation.

Question 10

What are the adverse effects of PPI?

Answer 10

Hyponatraemia

Increased risk of C. difficile infections

Osteoporosis - increased risk of fractures

Question 11

What are the indications of ranitidine?

Answer 11

2nd line to PPIs for peptic ulcer disease and gord.

Question 12

What are the actions of H2 antagonists?

Answer 12

Reduces gastric acid secretion

Question 13

What drugs can cause gynecomastia?

Answer 13

SOME DRUGS CREATE AWESOME KNOCKERS

Spironolactone (potassium sparing diuretic)
Digitalis
Cimetidine/ranitidine
Alcohol
Ketoconazole

Question 14

What are the adverse effects of spironolactone? (2)

Answer 14

Gynecomastia, breast tenderness

Renal impairment/hyperkalaemia

Question 15

What are the adverse effects of furosemide? (3)

Answer 15

Hypotension, hyponatraemia/hypokalaemia

Question 16

What anti-emetic to use for pregnancy associated nausea?

Answer 16

• Antiemetics generally avoided where possible unless vomiting is becoming problematic e.g. dehydration.
• Short term use of an antihistamine is first choice e.g. cyclizine

Question 17

What anti-emetic to use for chemotherapy induced?

Answer 17

5HT3 receptor antagonist e.g. ondansetron

Question 18

What anti-emetic to use for opioid induced?

Answer 18

antihistamine is first choice e.g. cyclizine

Question 19

What anti-emetic to use for motion sickness?

Answer 19

antihistamine is first choice e.g. cyclizine

Question 20

What is action of antihistamine/ anti-emetic cyclizine?

Answer 20

Act by blocking H1 receptors within the VC

Question 21

What is side effect of antihistamine cylizine/promethazine?

Answer 21

• Sedation: Particularly with promethazine

- Antimuscarinic properties: dry mouth and blurred vision.

Question 22

What is the action of dopamine receptor antagonists and example?

Answer 22

All act at the CTZ chemoreceptor trigger zone to block dopamine receptors and promote gastric emptying and motility.

Metoclopramide

Question 23

What are the CI of dopamine receptor antagonists?

Answer 23

Young children due to increased extrapyramidal side effects

GI perforation or obstruction can promote gastric emptying.

Question 24

What is a side effect of dopamine receptor antagonists?

Answer 24

Extrapyramidal side effects such as muscle contractions, involuntary movements

-Diarrhoea.

Question 25

Drugs that can cause dyspepsia?

Answer 25

aspirin + non-steroidal anti-inflammatory drugs (NSAIDs) can contribute to mucosal damage.

bisphosphonates e.g. risedronate.