Diarrhea/Abdominal Pain/Constipation Pharm

Question 1

Classes of Drugs For Diarrhea (4)

Answer 1

Prostaglandin Inhibitors (bismuth)
Opioid Agonists
Serotonin Antagonists
Chloride Channel Antagonists

Question 2

Loperamide

Drug Class, MOA, Adverse

Answer 2

Opioid Agonist

Inhibits intestinal wall muscles to slow peristalsis

Anticholinergic effects

Question 3

Diphenoxylate
Drug Classes (2), MOA and Adverse

Answer 3

Opioid Agonist mixed with Atropine

Inhibits intestinal wall muscles to slow peristalsis

Anticholinergic effects

Question 4

Eluxadoline

Drug Class, MOA (3), Indication, Adverse (2)

Answer 4

Opioid Agonist/Antagonist

Mu/Kappa Agonist to decrease peristalsis
Delta Antagonist to decrease secretions

Diarrhea-Type IBS (IBS-D)

Hepatic Toxicity
Pancreas Toxicity (Pancreatitis if pt has no gallbladder)

Question 5

Alosetron

Drug Class, MOA, Indication, Adverse

Answer 5

5-HT3 Antagonist

Selectively block GI 5HT3 to decrease pain, peristalsis and secretions

Chronic, severe, refractory IBS-D

Constipation leading to Ischemic Colitis

Question 6

Crofelemer

Drug Class, MOA (2) Indication and Adverse (2)

Answer 6

Chloride Channel Inhibitor

Blocks CFTR in GI tract to decrease fluid secretion

Non-infectious diarrhea in HIV/AIDS patients

Respiratory and Urinary Infections

Question 7

Antimuscarinic Agents

MOA, Examples (3), Indication, Adverse

Answer 7

Competitively blocks postganglionic cholinergic receptors to decrease GI spasms

Hyoscyamine
Dicyclomine
Clidinium/Chlordiazepoxide

Abdominal pain/spasms

Anticholinergic effects

Question 8

Drug Classes for Constipation (4)

Answer 8

Laxatives and Cathartic agents
Peripheral Opioid Antagonists
Guanylate Cyclase Agonists
Selective C2 Channel Agonists

Question 9

Linactolide

Drug Class, MOA (2), Indications (2)

Answer 9

Selective Guanylate Cyclase Agonist

Stimulates CFTR to increase fluid secretion

IBS-Constipation Type
Chronic Idiopathic Constipation

Question 10

Lubiprostone

Drug Class, MOA (2), Indications (3)

Answer 10

Prostaglandin E1 derivative

Activates GI C2 Chloride Channels to increase fluid secretion

IBS-Constipation Type
Chronic Idiopathic Constipation
Opioid Induced Constipation

Question 11

Opioid Antagonists

Examples (3), MOA, Indications (2), Specific Risk

Answer 11

Methylnaltrexone
Naloxegol
Alvimopan

Peripheral mu receptor antagonists

Opioid induced constipation
Alvimopan used for post-op ileus prophylaxis

Alvimopan increases risk of MI
(use REMS risk mitigation system)

Question 12

Classes of Laxatives (5)

Answer 12

Bulk Forming
Stool Softeners
Stimulants (Irritants)
Saline Agents
Osmotics

Question 13

Bulk Forming Agents

Examples (4), Timeline, Adverse (3)

Answer 13

Fiber
Psyllium
Cellulose
Calcium Polycarbophil

Takes 2-4 days to help

Bloating
Obstruction
Cellulose/Psyllium have lots of drug interactions

Question 14

Stool Softeners

MOA (4), Examples (2) and Timeline

Answer 14

Anionic Surfactants and Emoliants
Increase water secretion, decrease water reabsorption and oils penetrate stool

Docusate salts
Mineral Oil

Takes 1-3 days to help

Question 15

Stimulants (irritants)

MOA (3), Timeline, Adverse (3) Contraindications (3)

Answer 15

Irritate enterocytes to shut down Na/K ATPase and increase prostaglandin production**
Promote osmotic factors (castor oil)
Lubricate GI tract (glycerin)

Takes 12-36 hours to help

Abdominal cramping
Urine discoloration (senna)
Fluid/electrolyte disturbances

GI obstruction
Ileus
Stool impaction

Question 16

GI Stimulant Examples (5)

Answer 16

Sodium Picosulfate (pre-colonoscopy)
Castor oil
Senna
Bisacodyl
Glycerin

Question 17

Saline Agents

Examples (2), MOA (2) and Cautions (3)

Answer 17

Magnesium salts
Sodium Phosphate

Poorly absorbed
Create hyperosmotic stool to retain water

Diuretic drug interactions (electrolyte balance)
Renal Disease (electrolyte balance)
CHF/HTN (sodium)

Question 18

Osmotic Agents

MOA (2), Examples with Specific Uses (4)

Answer 18

Moisten/soften stool osmotiacally within 1-2 days
(minutes-hours if given in large doses)

Lactulose: Hyperammonemia
Polyethylene Glycol (PEG 350): Pre-colonscopy clean out
Magnesium Citrate
Sorbitol