Gi Pharmacology

Front 1

Major drug classes for Hearburn, GERD, and PUD

Back 1

Antacids
H2 Receptor Blockers
Mucosal Protective Agents
Proton Pump Inhibitors
Anti-cholinergics
Prostaglandin Analogs
Anti-microbial Agents

Front 2

What drugs inhibit secretion in the stomach?

Back 2

Cimetidine
Omeprazole Proton Pump Inhibitor
Prostaglandins
Muscarinic Antagonist
(COPM)
Cute Orientals Please Me

Front 3

What drug prevents contact in the stomach?

Back 3

Sucralfate --> it puts a barrier to protect the tissue.

Front 4

What drug neutralizes acid in the stomach?

Back 4

Antacids

Front 5

Name some systemic Antacid and non-systemic antacid

Back 5

Systemic Antacid: Sodium Bicarbonate --> breaks down Co2 leading u to burp...affects the entire pH of the body

Nonsystemic Antacid:
Aluminum Hydroxide + Magnesium Hydroxide Combinations (Maalox and Mylanta --> act locally

Front 6

What kind of anatacids is calcium carbonate (Tums)?

Back 6

Nonsystemic Antacid

Front 7

What are some contraindications/adverse effects of Aluminum Hydroxide/Magnesium Hydroxide?

Back 7

Contraindicated in patients with impaired renal function
Magnesium may cause diarrhea

Front 8

What are some adverse effects of Calcium Carbonate?

Back 8

- Calcium may cause constipation
- Calcium salts also may stimulate gastrin release

Front 9

Which is more effective: Calcium Carbonate or Magnesium Hydroxide?

Back 9

Magnesium/Aluminum Hydroxide

Front 10

What are some adverse effects of Aluminum Hydroxide?

Back 10

Constipation

Front 11

The duration of action of most common antacids (w/ the exception of sodium bicarbonate)

Back 11

Moderate

Front 12

What are some H2 receptor Blockers?

Back 12

Cimetidine
Ranitidine
Nizatidine
Famotidine

Front 13

What classification is Cimetidine? What are its effects?

Back 13

H2 blocker, inhibits p450

Front 14

Why does Rantidine have fewer side effects/drug interactions?

Back 14

Because it doesnt interact with P450

Front 15

What are the effects of histamine H2 receptor blockers?

Back 15

Inhibit secretion of gastric acid through competitive inhibition of Histamine H2 receptors

Front 16

What are H2 blockers used to treat?

Back 16

Prevention & tx of PUD, Esophagitis, GI bleeding, stress ulcers, and Zollinger-Ellison Syndrome

Front 17

What are other receptors do H2 receptors block?

Back 17

- not only block effects of histamine but also blunt responses to ACh
- Used in gastric ulcers, alone or in combination with antibiotics to eradicate H. pylori

Front 18

Compare Rantidine and Cimentidine as H2 blockers.

Back 18

Rantidine is More potent than Cimetidine

Rantidine has no antiandrengenic or prolactin stimulating effects

Unlike cimetidine, Rantidine does not inhibit mixed functo oxidases will not affect concentrations of other drugs

Front 19

What is Famotidine?

Back 19

H2 Blocker
Similar to Ranitidine
50 times more potent than Cimetidine
3-20 times more potent than Ranitidine

Front 20

What is Nizatidine?

Back 20

Unlike above drugs not metabolized by liver

Elimited by kidney

Bioavailability is 100%

Front 21

What are proton pump inhibitors?

Back 21

Strong inhibitors of gastric acid secretion through irreversible inhibition of proton pump, preventing “pumping” or release of gastric acid (24 hr action)

Front 22

When are PPIs used?

Back 22

Indicated in PUD, Gastritis, GERD, & Zollinger-Ellison syndrome

Front 23

How are PPis in comparison to H2 receptor blockers?

Back 23

Faster relief and healing than H2 receptor blockers

Front 24

How effective is the decrease of acid secretion with PPIs?

Back 24

Decreases acid secretion by up to 95% for up to 48 hours

Front 25

When should PPIs be given?

Back 25

1 hour before food, can affect acid secretion for 24 hours.

Front 26

How long do PPIs need to be taken in order to be effective?

Back 26

because not all H-pumps are inactivated with the first dose, up to 3-4 days of daily medication are required before a full acid-inhibiting potential is reached

Front 27

How are PPIs used to treat with H. Pylori?

Back 27

used in gastric ulcers, alone or in combination with antibiotics (for H. pylori)

Front 28

What is the drug of choice for Zollinger-Ellison Syndrome
?

Back 28

PPI

Front 29

What class is Pirenzipine in?

Back 29

Anti-Cholinergics (zipine)

Front 30

What are the effects of Pirenzipine?

Back 30

1. Muscarinic M1 acetylcholine receptor antagonist
2. Blocks gastric acid secretions

Front 31

What are side-effects of Anticholinergics? Are they commonly used?

Back 31

Rarely used, primarily as adjunct therapy
Anticholinergic side effects (anorexia, blurry vision, constipation, dry mouth, sedation)

Front 32

What is Omeprazole classified as?

Back 32

PPI

Front 33

"idine"

Back 33

histamine or anti-histamine drugs

Front 34

What can Sucralfate be used for?

Back 34

Can be used to prevent & treat PUD

Front 35

How is Sucralfate activated (similar to PPIs)? What are some disadvantages of the drug?

Back 35

1. It requires an acid Ph to activate
2. Forms sticky polymer in acidic environment and adheres to the ulcer site, forming a barrier
3. May bind with other drugs and interfere with absorption

Front 36

What are chelated bismuths (pepto-bismol) used for? What are some disadvantages?

Back 36

Protects the ulcer crater and allows healing
Some activity against H. pylori
Can cause black stools, constipation

Front 37

What is Misoprostol? When is it used?

Back 37

Prostaglandin E1 analog (PG stimulate mucus and bicarbonate production)

Used when treatment with NSAIDs inhibits endogenous PG synthesis

Used in treatment of NSAID induced injury

Front 38

When do you not give Misoprostol?

Back 38

Do not give to women of childbearing years unless a reliable method of birth control can be DOCUMENTED

Front 39

Name the combination of drugs used to treat H. Pylori

Back 39

Bismuth - Disrupts bacterial cell wall

Clarithromycin - Inhibits protein systhesis

Amoxicillin - Disrupts cell wall

Tetracycline - Inhibits protein synthesis

Metronidazone - Used often due to bacterial resistance to amoxicillin and tetracycline, or due to intolerance

Front 40

Bismuth Antibiotic effect

Back 40

Disrupts bacterial cell wall

Front 41

What is clarithromycin used for?

Back 41

Inhibits protein systhesis

Front 42

What is amoxicillin used for?

Back 42

Disrupts cell wall

Front 43

What is tetracycline used for?

Back 43

Inhibits protein synthesis

Front 44

When is metronidazone used?

Back 44

Used often due to bacterial resistance to amoxicillin and tetracycline, or due to intolerance

Front 45

Whats the triple and quadriple therapy to treat H. Pylori?

Back 45

Triple Therapy - 7 day treatment - Effective 80-85%
Proton pump inhibitor + amoxicillin/tetracycline + metronidazone/clarithomycin

Quadruple Therapy - 3 day treatment, as efficacious as triple therapy
- Add Bismuth to triple therapy

Front 46

What are the treatments for Inflammatory Bowel Disease?

Back 46

Aminosalicylates - for mild symptoms

Corticosteroids - for moderate symptoms -Prednisolone

Thiopurines - for active and chronic symptoms (Azathioprine, mercaptopurine ii inhibits ribonucleotide synthesis

Methotrexate - for active and chronic symptoms Probably inhibition of cytokine and eicosanoid synrthesis

Cyclosporin - for active and chronic symptoms refractory to corticorsteroids- (significant side effects)

Infliximab - antibody infusion- Anti TNF-α monoclonal antibody

Front 47

What can Aminosalicylates beeen used to treat?

Back 47

Mild symptoms of IB Disease

Front 48

What can coritcosteroids be used to treat?

Back 48

Moderate symptoms of IBD. Predisolone commonly used.

Front 49

What can Thiopurines be used to treat?

Back 49

Active and Chronic Symptoms of IBD

Front 50

What can Methotrexate be used to treat?

Back 50

Active and Chronic Symptoms of IBD --> similar to Thiopurine except it targets cytokine and eicoside synthesis.

Front 51

What can Cyclosprorin be used to treat

Back 51

active and chronic symptoms of IBD refractory to corticorsteroids- (significant side effects)

Front 52

What can Infliximab be used to treat?

Back 52

Antibody infusion of IBD (Anti TNF alpha monclonal antibody

Front 53

What can be used to treat constipation?

Back 53

1. Bulking agents
2. Osmotic laxatives
3. Stimulant drugs
4. Stool softners

Front 54

How do bulk laxatives work?

Back 54

1. Increase in bowel content volume triggers stretch receptors in the intestinal wall

2. Causes reflex contraction (peristalsis) that propels the bowel content forward

Front 55

What are examples of bulk laxatives?

Back 55

1. Psyllium, linseed
2. Bran
3. Methylcellulose

Front 56

What are charachteristics of Bulk Laxatives?

Back 56

Insoluble and non-absorbable
Non digestible
Must be taken with lots of water! (or it will make constipation worse)

Front 57

When is saline and osmotic laxatives used?

Back 57

purge intestine (e.g. surgery, poisoning)

Front 58

MOA of Saline and Osmotic Laxatives

Back 58

drawn into the bowel by osmotic force, increasing volume and triggering

Front 59

What are nondigestible sugars and alcohols?

Back 59

Lactulose (broken down by bacteria to acetic and lactic acid, which causes the osmotic effect)

Front 60

What are examples of salts?

Back 60

Milk of Magnesia (Mg(OH)2) Mucosal Protective Agents
Epsom Salt (MgSO4)
Glauber’s Salt (Na2SO4)
Sodium Phosphates (used as enema)
Sodium Citrate (used as enema) Mucosal Protective

Front 61

What are examples of Stool Softeners (Emollients)?

Back 61

Docusate sodium (surfactant and stimulant)
Liquid Paraffin (oral solution)
Glycerin suppositories --> kids

Front 62

What can irratant/stimulate laxatives (cathartics) do? When is it used?

Back 62

-Increases intestinal motility
-Irritate the GI mucosa and pull water into the lumen
-Indicated for severe constipation where more rapid effect is required (6-8 hours)

Front 63

What are examples of Cathartics?

Back 63

Castor Oil - From the Castor Bean
Aloe, rhubarb
Senna - Plant derivative
Bisacodyl- stimulates intestinal muscle
Lubiprostone -PGE1 derivative that stimulates chloride channels, producing chloride rich secretions

Front 64

What are arthraquinones?

Back 64

Active ingredient of Senna sp. (Folia and fructus sennae), Rhamnus frangulae (cortex frangulae) and Rheum sp. (rhizoma rhei): contain inactive glycosides => active anthraquinones released in colon take 6-10 hours to act

These are large bowel irritants!

Front 65

What is the most common cause of constipation?

Back 65

Laxative ABUSE!

Front 66

What are examples of large bowel irritants?

Back 66

Diphenolmethanes and Biscacodyl

Front 67

When is Bisacodyl used? Kinds of administration?

Back 67

Oral administration: effect in 6-8 hrs
Rectal administration: effect in 1 hr
Often used to prepare for intestinal surgery

Front 68

What do anti-diarrheals do?

Back 68

Reduce peristalsis by stimulating opioid receptors in the bowel

Front 69

What are examples of anti-diarrheals?

Back 69

Morphine
Codeine
Diphenoxylate (Lomotil)
Loperamide
--> 40-50x more potent than morphine
--> Poor CNS penetration
--> Increases transit time and sphincter tone

Front 70

What are contraindications of anti-diarrheals?

Back 70

Toxic Materials
Microorganisms (salmonella, E.coli)
Antibiotic associated

Front 71

What is Morphine most commonly used and how is it different from anti-diarrheal? What is the problem?

Back 71

1. analgesic - most common use

2. antidiarrheal - occurs in lower doses than analgesic effects

3. problem: subject to abuse

4. prescribed as paregoric for diarrhea - hydroalcoholic solution of opium powder; contains 2 mg of morphine per teaspoonful

Front 72

What is the MOA of morphine in the stomach? (Generally)

Back 72

1. decreased stomach emptying
2. decreased contractions
3. increased net fluid and electrolyte absorption

Front 73

What is the effecting of decreasing the stomach emptying?

Back 73

1. reduced rate of chyme presentation to the bowel
2. more time for intestinal absorption

Front 74

What is the effect of decreased contractions caused by morphine?

Back 74

1. decreased Ach release from postganglionic cholinergic nerves in the gut

2. slowed propulsion through the small and large intestine

Front 75

What is Diphenoxylate/Lomotil used for? What are its charachteristics?

Back 75

1. Anti-Diarrheal.
2. There is little CNS penetration in therapeutic doses
3. not water soluble, making i.v. administration almost impossible
4. sub-therapeutic amount of atropine included to "poison" a drug abuser
Lomotil structure similar to meperidine

Front 76

What is Loperamide used for? What are the major characteristics?

Back 76

Anti-Diarrheal

little or no addictive liability - no CNS penetration
not water soluble
no atropine in the preparation - not necessary
long-acting - the half life is 7 to 14 hrs.

Front 77

What are adsorbents used for? What are the pinciple agents?

Back 77

Anti-Diarrheal

1. attapulgite - a clay
2. bismuth subsalicylate - active ingredient in pepto-bismol; demonstrated effectiveness

Front 78

What is the mechanism of adsorbents?

Back 78

mechanism: unknown, may adsorb toxic substances in the gastrointestinal tract

Front 79

What is the pharmacological treatment of C. Difficile?

Back 79

1. Discontinue offending antibiotic
2. Metronidazole (contraindicated in patients with liver or renal impairment)
3. Vancomycin (contraindicated in patients with renal impairment)

Front 80

What is the treatment for diarrhea with no invasive infection?

Back 80

The goal of therapy is to maintain adequate hydration.

Avoid substances that will increase intestinal secretions (caffeinated and alcoholic beverages, spicy foods, milk products) and adequate intake of (2-3 liters) of fruit juices and non-carbonated beverages.

Front 81

What are Antiflatulants?

Back 81

Used to relieve the painful symptoms associated with gas

Front 82

What is Simethicone?

Back 82

An Antiflatulant that alters elasticity of mucus-coated bubbles, causing them to break

Large bubbles -> smaller bubbles, and less pain

Used often, but limited data regarding effectiveness

Front 83

To induce emesis (vomiting) what agent can be used?

Back 83

Syrup of Ipecac Emetic

Front 84

When is acceptable to use syrup of ipecac emetic?

Back 84

1. There is no contraindication to the use of ipecac
2. There is substantial risk of serious toxicity to the victim
3. There is no alternative therapy available or effective to decrease gastrointestinal absorption (e.g., activated charcoal)
4. There will be a delay of greater than 1 hour before the patient will arrive at an emergency medical facility and ipecac syrup can be administered within 30-90 minutes of the ingestion
5. Ipecac syrup administration will not adversely affect more definitive treatment that might be provided at a hospital

Front 85

Anti-emetic drugs include.....

Back 85

H1 antagonists: Meclizine, promethazine, dimenhydramine…

Muscarinic receptor antagonists: Scopolamine (motion sickness)

Benzodiazepines: Lorazepam (during chemotherapy)

D2 antagonists: have also peripheral prokinetic effects => increase motility of the GI tract => increases the rate of gastric emptying. Caution in patients with Parkinson’s disease!
Metoclopramide
Domperidone

Cannabinoids:
Marijuana
Synthetic cannabinoids: during chemotherapy
Nabilone
Dronabinol

Front 86

What can antihistamines Diphenhydramine be used?

Back 86

Are useful in management of nausea and vomiting of motion sickness or other unknown causes

Front 87

What is the active ingredient in Cannaboids? What are examples of Cannaboids used?

Back 87

Tetrahydrocannabinol (THC) is the active ingredient

Dronabinol (Marinol®)
Nabilone (Cesamet®)

Front 88

What are examples of benzodiazepines used for nausea and vomiting?

Back 88

Alprazolam
Lorazepam

Front 89

"Zolam" Drugs

Back 89

Benzodiazepines

Front 90

What corticosteroids for emesis? When is it used?

Back 90

1. Dexamethasone
2. Methylprednisolone

used for mildly emeogenic chemotherapy. It may block prostaglandins

Front 91

What drug can stimulate GI Motility?

Back 91

Metoclopramide

Front 92

What does Metoclopramide do and when is it used? (Hint not emesis)

Back 92

It enhances tone and motility in esophagus and stomach, facilitates gastric emptying

It stimulates gastric motility (prokinetic) without increasing acid secretion

Its used in reflux esophagitis (heartburn), disorders of gastric emptying (diabetic gastroparesis) and intractable hiccup