Constipation

Question 1

Groups of drugs used for constipation (4 groups)

Answer 1

Prokinetic drugs
Muscarinic receptor antagonists
Laxatives
Serotonin agonists

Question 2

Serotonin agonists - MOA (for constipation)

Answer 2

Promotes motility by activation of 5-HT4 receptors causing release of ACh from intrinsic submucosal neurons.

Question 3

Prokinetic drugs (1 drug)

Answer 3

Metoclopramide

Question 4

Metoclopramide - indications

Answer 4

GERD, diabetic gastroparesis, antiemesis.

Question 5

Metoclopramide - MOA

Answer 5

Block dopamine D2 receptors, releasing ACh.
Increased motility and resting pressure at lower esphageal sphincter.
Blocks D2 and 5-HT3 receptors in CTZ

Question 6

Metoclopramide - contraindications

Answer 6

Pt with seizures, mechanical GI obstruction or hemorrhage, pheochromocytoma

Question 7

Metoclopramide - adverse effects

Answer 7

Seizures, hyperprolactinemia.

Question 8

Muscarinic receptor antagonists (5 drugs)

Answer 8

Atropine
Hyoscyamine
Dicyclomine
Scopolamine
Pirenzepine

Question 9

Which muscarinic receptor antagonist is used in PUD?

Answer 9

Pirenzepine

Question 10

Muscarinic receptor antagonists - indications

Answer 10

Relief of intestinal cramping and pain.

Question 11

Laxatives - groups

Answer 11

Bulk-forming laxatives
Surfactant laxatives
Osmotic laxatives

Question 12

What are the safest types of laxatives?

Answer 12

Bulk-formin laxatives

Question 13

Bulk-forming laxatives (2 drugs)

Answer 13

Psyllium hydrophilic mucilloid

Calcium polycarbophil

Question 14

Bulk-forming laxatives - MOA

Answer 14

Absorb and retain water, increasing the mass of the intestinal material. Mechanical distention stimulate peristalsis

Question 15

Bulk-forming laxatives - indications

Answer 15

Chronic constipation.

Diarrhea

Question 16

Surfactant laxatives (2 drugs)

Answer 16

Docusate sodium

Docusate calcium

Question 17

Surfactant laxatives - indications

Answer 17

Hemorrhoids

Post abd surgery

Question 18

Surfactant laxatives - MOA

Answer 18

Incorporate water to fatty intestinal material

Question 19

Osmotic laxatives - groups with examples

Answer 19

Poorly absorbed salts (saline laxatives): magnesium oxide and sodium phosphate
Poorly absorbed sugars: Lactulose, PEG
Stimulant (secretory) laxatives: bisacodyl

Question 20

Osmotic laxatives - MOA

Answer 20

Attract and retain water. Increased intraluminal pressure and stimulate peristalsis

Question 21

Poorly absorbed sugars - indications

Answer 21

Chronic constipation

Question 22

Lubiprostone - indications

Answer 22

Chronic idiopathic constipation, IBS with constipation

Question 23

Lubiprostone - MOA

Answer 23

Activates chloride CIC-2 channel in the intestinal lumen. Stimulation of chloride-rich fluid which increases intestinal motility