Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
22 Cards in this Set
- Front
- Back
|
What are the symptoms of IBS?
|
Abdominal Pain
Diarrhea Constipation Bloating |
|
|
What is the effect of serotonin in the GI system on the-
5HT3 Receptor? 5HT4 Receptor? |
5HT3 Receptor-
Increased visceral perception. Increased GI motility. 5HT4 Receptor- Increased peristalsis. Increased secretion. |
|
|
BULK FORMING LAXATIVES
Mechanism of Action? |
Undigested contents of bulk forming laxative travel to colon.
In colon, they absorb water and increase in size. They also provide food for some bacteria which also increases fecal mass. Increased fecal mass causes mechanical distension of the colon wall. Activation of stretch receptors causes increased peristalsis and decreased transit time. |
|
|
OSMOTIC LAXATIVES
Mechanism of Action? |
Increases osmotic gradient in the SMALL INTESTINE and/or COLON.
Causes influx of water into the intestinal lumen. Increased fecal mass causes mechanical distension. Activation of stretch receptors causes increased peristalsis and decreased transit time. |
|
|
STIMULANT LAXATIVES
Mechanism of Action? |
Exact mechanism is unclear.
1. Acts as a mild local irritant in the small intestine or colon. -Irritation activates enteric NS. -Stimulation of peristalsis. 2. Alteration of fluid and electrolyte absorption. -Net intestinal fluid volume increases. -Mechanical distension triggers stretch receptors. -Increased peristalsis. |
|
|
LUBIPROSTONE
Mechanism of Action? |
Selective Type 2 Chloride Channel Activator (CIC-2)
Activates CIC-2 on the luminal membrane of the intestinal epithelial cells. Activation causes CIC-2 channels to open and Chloride is actively secreted into the intestinal lumen (from inside the intestinal epithelial cells). As negatively charged chloride moves into the lumen, sodium and water follow. Increased intraluminal volume causes mechanical distension. Stretch receptors are triggered and peristalsis is stimulated. |
|
|
BULK FORMING LAXATIVES
Clinical Uses? |
Acute Constipation
Chronic Constipation |
|
|
OSMOTIC LAXATIVES
1. MAGNESIUM CITRATE 2. LACTULOSE 3. PEG (POLYETHYLENE GLYCOL) Clinical Uses? |
1. MAGNESIUM CITRATE-
Acute Constipation (lower dose) Chronic Constipation (lower dose) Rapid Bowel Evacuation (higher dose) 2. LACTULOSE Acute Constipation Chronic Constipation 3. POLYETHYLENE GLYCOL Acute Constipation (PEG powder) Chronic Constipation (PEG powder) Rapid Bowel Evacuation (PEG Electrolyte Solution) |
|
|
STIMULANT LAXATIVES
Clinical Uses? |
Acute Constipation
Chronic Constipation Sometimes used in combination with PEG or Magnesium Citrate for Rapid Bowel Evacuation. (Not strong enough on its own.) |
|
|
LUBIPROSTONE
Clinical Uses? |
Chronic Constipation
IBS-C |
|
|
DOCUSATE
Mechanism of Action? |
Anionic surfactant.
Lowers fecal surface tension to allow penetration of stool by lipids and water. Softening of feces makes it EASIER TO GO (but does not directly make you go.) |
|
|
ANTIDIARRHEAL OPIOIDS
Mechanism of Action? |
The gut contains a large number of opioid receptors.
Opioids bind to gut mu receptors- reduction of peristalsis. Opioids bind to gut delta receptors- Reduction of intestinal secretions. Prolonged transit time and increased fecal viscosity. |
|
|
DIPHENOXYLATE & LOPERAMIDE
Clinical Uses? |
Can control diarrhea due to almost any cause.
***Diphenoxylate and Loperamide are the opioid agonists with the greatest ratio of intestinal smooth muscle:CNS activity. |
|
|
LOMOTIL
What is in it? |
Diphenoxylate + Atropine
*The atropine is added in a subtherapeutic dose to discourage drug seekers from abusing it. |
|
|
BISMUTH SUBSALICYLATE
Mechanism of Action (for treating diarrhea)? |
BISMUTH-
Has direct antimicrobial effect and binds enterotoxins. Helps prevent travelers diarrhea. SUBSALICYLATE- Inhibits the production of prostaglandins. Decreases intestinal secretions. *Also does other stuff when used for treatment of gastric or duodenal ulcers. |
|
|
ALOSTERON
Mechanism of Action? Clinical Use? |
MECHANISM:
Blocks 5HT3 serotonin receptors in the gut. Reduces visceral sensation in the gut (reduces abdominal pain). Reduces colonic transit and secretion. CLINICAL USE: Severe IBS-D in women. |
|
|
TEGASEROD
Mechanism of Action? Clinical Use? |
MECHANISM:
Activation of 5HT4 serotonin receptors in the gut. Increases gut motility. Promotes fluid secretion. CLINICAL USE: IBS-C Idiopathic Chronic Constipation |
|
|
ALOSTERON
Adverse Effects? |
CONSTIPATION
-Ileus -Bowel Obstruction -Toxic Megacolon -Fecal Impaction -Perforation -Patients should be advised to stop taking Alosteron if they develop constipation. ISCHEMIC COLITIS -Mechanism is unclear. Thought to possibly cause mesenteric vasoconstriction. |
|
|
ALOSTERON
Contraindications? |
HISTORY OF:
-Intestinal obstruction, stricture, toxic megalocolon, GI perforation, adhesions. -Ischemic Colitis -Active Diverticulosis -Crohn's Disease, Ulcerative Colitis |
|
|
LAXATIVES- ADVERSE EFFECTS:
-Bulk Forming Laxatives? -Osmotic Saline Laxatives? -Osmotic Non-digestible Sugar Laxatives? -Lubiprostone? |
BULK FORMING LAXATIVES:
-Flatulence/ Bloating/ Abdominal Cramps OSMOTIC (SALINE) LAXATIVES: -Fluid & Electrolyte Imbalances OSMOTIC (NON-DIGESTIBLE SUGARS) LAXATIVES: -Flatulence/ Bloating/ Abdominal Cramps LUBIPROSTONE: -Nausea -Diarrhea |
|
|
ANTIDIARRHEAL OPIOIDS
Adverse Effects? |
Drowsiness
Dizziness Abdominal cramps *Excessive use can precipitate toxic megacolon in patients with severe ulcerative colitis! |
|
|
ANTIDIARRHEAL OPIOIDS
Contraindications? |
Contraindicated for treatment of diarrhea in patients with:
Severe Ulcerative Colitis Pseudomembranous Colitis Shigella |
