Term
| What is coupled to Na+ entry into the villous enterocyte? |
|
Definition
| absorption of glucose and amino acids |
|
|
Term
| How is electrical neutrality maintained in the enterocyte? |
|
Definition
| movement of Cl- from the lumen through intercellular spaces to the interstitial compartment |
|
|
Term
| How is Na+ extruded from the enterocytes? |
|
Definition
| by Na+,K+ATPase located in the basolateral membrane |
|
|
Term
| What factors Enhance fluid absorption in the colon? |
|
Definition
Short-chain fatty acids
Aldosterone (enhanced Na+ uptake)
Somatostatin
antidiuretic hormones
dopaminergic agonists
adrenergic agonists |
|
|
Term
| What factors Reduce fluid absorption in the colon? |
|
Definition
Long-chain fatty acids
dihydroxy bile acids
cholinergic agonists
prostaglandins
vasoactive intestinal peptide
cholera toxin (cAMP activation) |
|
|
Term
| What factors can cause constipation? |
|
Definition
Excessive water reabsorption
Decreased Motility |
|
|
Term
| What factors can cause diarrhea? |
|
Definition
Increased motility
Excessive Secretion
Decreased absorption |
|
|
Term
| What are the 5 groups of Laxatives? |
|
Definition
Dietary Fiber and Bulk-forming laxatives
Surfactant laxatives
Osmotic Laxatives
Stimulant Laxative
Miscellaneous laxatives |
|
|
Term
| Dietary Fiber and Bulk-forming Laxatives |
|
Definition
Psyllium husk
Semisynthetic celluloses
Polycarbophils |
|
|
Term
|
Definition
Psyllium Husk
Hydrophilic muciloid that forms getatinous mass when mixed with water |
|
|
Term
|
Definition
Semisynthetic celluloses
Hydrophilic and digestible
Forms a colloid mass with water
(Citrocel and Cologel form Colloid) |
|
|
Term
| What bulking agent may inhibit coumarin absorption? |
|
Definition
|
|
Term
| Which bulking agent can cause allergic reactions, flatulence, and intestinal obstruction? |
|
Definition
|
|
Term
| What bulking agent can cause borborygmi? |
|
Definition
|
|
Term
| Which Bulking agent may bind and impede drug absorption? |
|
Definition
Semisynthetic celluloses
(Citrucel and Cologel) |
|
|
Term
|
Definition
Docusate Sodium
Castor Oil |
|
|
Term
| What Surfactant Laxative is weakly acting Anionic Surfactant? |
|
Definition
|
|
Term
| What Surfactant Laxative is not to be used during abdominal pain, nausea, or vomiting? |
|
Definition
|
|
Term
| What Surfactant Laxative can irritate the intetinal mucosa and increase intestinal absorption of other drugs? |
|
Definition
|
|
Term
| What surfactant laxative stimulates intestinal peristalsis? |
|
Definition
|
|
Term
| How does Castor oil work? |
|
Definition
| Hydrolyzed to Ricinoleic Acid-> produces catharsis-> complete evacuation of bowels |
|
|
Term
| What surfactant can induce uterine contraction in pregnant women? |
|
Definition
|
|
Term
| What are the most potent laxatives? |
|
Definition
Stimulant Laxatives
Bisacodyl
Senna |
|
|
Term
| What is the mechanism of action of the stimulant laxatives? |
|
Definition
a. Act on Large Bowel
b. Increase permeability of intestinal mucosa
c. Increase Back diffusion of water and electrolytes
d. Increase propulsive contractility of colon by stimulating colonic mucosal myenteric plexus
e. Stimulate prostaglandin synthesis and increase intestinal secretions |
|
|
Term
| What stimulant laxative is a prodrug that is converted by enteric bacteria into it's active form? |
|
Definition
|
|
Term
| What Stimulant Laxatives act by promoting colonic motility? |
|
Definition
|
|
Term
| What Stimulant laxative can cause melanotic pigmentation of the colonic mucosa in large doses? |
|
Definition
|
|
Term
| How do Saline laxatives work? |
|
Definition
Laxatives containing magnesium cations or other nonabsorbable molecules
Exert an osmotic effect which retains water in the lumen of the GI tract |
|
|
Term
| What are the Magnesium containg laxatives? How do they work? |
|
Definition
Magnesium sulfate: Epsome Salt
Magnesium hydroxide: Milk of Magnesia
Magnesium citrate: Citroma (cathartic)
Osmotic effect and release of CCK-> increases motility and secretion |
|
|
Term
| How are Posphate containing laxatives administered? |
|
Definition
Enema
Fleet Enema
Oral Sodium Phosphate tablets (Visicol, OsmoPrep) |
|
|
Term
| What are the Nondigestible sugars and alcohols? |
|
Definition
Lactulose (Cephylac)
Polyethylene glyco |
|
|
Term
|
Definition
Produces Osmotic effect
Metabolized by enteric bacteria to organic acids-> lactic, formic and acetic acid
Fecal Acidifier-> traps ammonia in ammonium form (non-toxic) |
|
|
Term
| What laxative is a mixture of hydrocarbons that penetrates and softens the stool? |
|
Definition
|
|
Term
| What are some general side effects of laxative abuse? |
|
Definition
Overuse leads to thorough constipation that requires several days to accumulate bulk
Lag in defecation is interpreted as continued constipation
Take more laxatives-vicious cycle
Bowel becomes unresponsive |
|
|
Term
| What are the 3 groups of Antidirrheal agents? |
|
Definition
Agents that absorb water
Absorbers of etiological factos in the lumen
Agents that alter intestinal motility |
|
|
Term
| What antidirrheal agents are used to absorb water? |
|
Definition
Cellulose derivatives
Semisynthetic polysaccharides
(metamucil) |
|
|
Term
| How do Bismuth subsalicylate, charcoal, Attapulgite, and Magnesium Aluminum Disilicate work as antidirrheal agents? |
|
Definition
| Adsorb harmful bacteria, viruses, or toxin. |
|
|
Term
| How do Opiates work as antidirrheal agents? |
|
Definition
*Increase contact time between ingested matter and the reabsorbtive intestinal epithelium*
Decrease salivary, gastric and intestinal secretions
Decrease motility of stomach and intestines
Increase muscle tone
Increase sphincter tone(reduce urgency)
Anti-spasmodics - decrease cramps |
|
|
Term
| What Opioid is formulated for diarrhea? |
|
Definition
|
|
Term
| What Opioid interacts with intestinal opioid receptors and binds to and inhibits the calcium-binding protein calmodulin? |
|
Definition
|
|
Term
| What opioid should not be used in Ulcerative colitis? |
|
Definition
|
|
Term
| What is the mechanism of action of the anticholinergic antidirrheal agents? |
|
Definition
Block cholinergic receptors and reduce vagal stimulation.
Anti-spasmodic |
|
|
Term
| What type of drugs are used in the treatment of motion sickness? |
|
Definition
Anticholinergics
H1 antihistamines |
|
|
Term
| What is the mechanism of action of Scopolamine? |
|
Definition
Anticholinergic
Blocks activation of muscarinic receptors by acetyl choline, to inhibit cochlear sensation of motion projected via cholinergic fibers of the auditory canal to the CTZ |
|
|
Term
| What are some side effects of Scopolamine? |
|
Definition
|
|
Term
| What is the mechanism of H1 antihistamines on the treatment of motion sickness? |
|
Definition
| Older Antihistamines exhibit anti-cholinergic effects in addition to H1 effects |
|
|
Term
| What is the H1 antihistamines used for motion sickness? |
|
Definition
|
|
Term
| What H1 agent is used for prophylaxis of motion sickness? |
|
Definition
| Dimenhydrinate (Dramamine) |
|
|
Term
| What is the Antidopaminergics used as antiemetics? |
|
Definition
|
|
Term
| What is the mechanism of the Antidopaminergics? |
|
Definition
| Block dopamine receptors in the CTZ |
|
|
Term
| What Antiemetic is used for N&V and intractable hiccough? |
|
Definition
Chlorpromazine
(anticholinergic and antidopaminergic) |
|
|
Term
| What antiemetic is a centrally acting anticholinergic and antidopaminergic? |
|
Definition
|
|
Term
| What are the side effects of Antidopaminergics? |
|
Definition
Extrapyramidal - Dystonias
(short-term use) |
|
|
Term
| What are the most effective antiemetics? |
|
Definition
|
|
Term
| How do the antiemetic serotonin antagonists work? |
|
Definition
Block 5-HT3 receptors in the stomach and small intestines
Block 5HT3 receptors in the CTZ that are involved in stimulating the VC to produce emesis |
|
|
Term
| What are the Serotonin Antagonists? |
|
Definition
|
|
Term
| What antiemetic drug is used to prevent emesis induced by cytotoxic agents like cisplatin? |
|
Definition
|
|
Term
| What drug is give via a transdermal patch behind the ear? What it is it's mechanism? |
|
Definition
Scopolamine
Anticholinergic - blocks muscarine receptors on CNVIII travelling to the CTZ |
|
|
Term
| Why are corticosteroids (dexamethasone and methyl prednisolone) used in combo with other antiemetics? |
|
Definition
| Enhance antiemetic effects and reduce side effects of other drugs |
|
|
Term
| What antiemetic is a Substance P/Neurokinin 2 receptor antagonist? |
|
Definition
Aprepitant
Crosses the BBB |
|
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