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