Digestive Flashcards
True choleretics
Phenobarbital
Hydrocholeretics
Ox bile extract, dehydrocholica acid, cynalra scolimus
Choleretics
drug which stimulate production of bile by the liver
Cholagogues/cholecystokinetics
decrease biliary stasis by stimulating flow of bile into duodenum
Real cholagogues
magnesium sulphate, olive oil, sunflower oil, yolk
Hydrocholeretics and cholagogues are administered in
biliary dyskinesia (contraindicated in gallstones)
Phenobarbital
anticonvulsant and sedative-hypnotic induces CYP450 to decrease serum bilirubin, used in neonatal hyperbilirubinemia, cholestasis, CONTRAINDICATIONS respiratory problem, lactation period
Hydrocholeretics
increase volume of diluted bile, do not stimulate secretion of biliary constituents, excreted through bile they act by an osmotic mechanism, stimulate antitoxic function of liver (choleric and cholecystokinetic), laxative, spasmolytic, anti-inflammatory effects. INDICATIONS : acute/chronic cholecystitis, liver cirrhosis, constipation
Gallstones
cholesterol component, not soluble in water, poorly soluble in bile, precipitation of biliary salts in biliary cholesterol supersaturation, risk factors are female, fat, fair, forty, fertile, family. Modifying bile composition, drugs dissolve gallstones prevent precipitation and favor dissolving. Pharmacological/surgical treatment prevent complications
Ursodeoxycholic acid
Replaces endogenous biliary acids (hydrophobic) with hydrophilic and nontoxic ones, suppresses cholesterol secretion and inhibits intestinal absorption of cholesterol, bile acids used gradually to dissolve small stones, no influence on calcium. INDICATIONS: biliary lithiasis with cholesterol (radiotransparent, small gallstones), primary biliary cholangitis (delated liver transplant). ADVERSE EFFECTS diarrhea, skin rash, CONTRAINDICATIONS cholecystitis, obstruction of biliary tract, biliary contraction disorder, pregnancy first trimester/;actating. At least 6 (to 24) months of treatment, success rate 60% after 6 months but resurrect is common, expensive and reserved for those unfit for surgery
Bilichol
decrease endogenous production of cholesterol, prevents formation of gall stones, increases biliary flow and antispastic, inhibits HMG-CoA reductase, desaturates bile. I: biliary duct dyskinesia, cholecystitis, chlelythiasis; 1-2 camps. 3 times/day, before meal
Rowachol
almost like Bilichol, but only in cholelythiasis
Constipation
hard/dry stool in elderly, sedentary, pregnancy, hypothyroidism, (diverticulitis, colorectal cancer, hernia, hemorrhoids, anal fissues), neurological (Parkinson, multiple sclerosis, spinal lesion).
Drugs responsible for constipation
opioids, anticholinergics, tricyclic antidepressants, neuroleptics, antihistaminic, spasmolytics
Laxative administration
before initiation: rich fiber diet, 1,5 to 2L liquid, physical exercise, empty intestinal content before colonoscopy and surgical interventions, painful anal lesions, avoid vascular complications due to increased intra-abdominal pressure, food/drug intoxications
Result of laxatives
normal stool, usually after 8-12 hours, sometimes days, high doses have a purgative effect, only 5-10% absorbed from GI tract, locally through different mechanisms, forbidden in ileum, abdominal pain, without detected cause, acute intestinal diseases. Caution in pregnancy and lactation period.
Purgatives
eliminate intestinal content through semisolid first then liquid stool with latency of 2-6 hours
Misuse/chronic administration of lazatives
dependence (reduced peristalsis), hydroelectric imbalance (hypokalemia, hyponatremia with secondary hypoaldosteronism) hypokalemia more sever with loop diuretics, thiazides, glucocoticoids, amphotericin b
Bulk forming agents- fibers - plant based foods
methylcellulose, psyllium seeds
Hyperosmotic agents
polyethylene glycol (peg macrogol), lactulose, magnesium or sodium salts
Laxatives and Purgatives
bulk forming agents, hyper osmotic agents, stool softeners, stimulant agents, new laxatives
Stool softeners
docusate, mineral oil
Stimulant agents
Senna, bisacodyl, castor oil
New laxatives
prucaloprid, linaclotid, methynaltrexone
Methylcellulose, psyllium seeds
resist enzymatic digestion, work locally by absorbing water, swelling and increasing bulk of stool, stimulating peristalsis and defecation, latency 12-36 hours, I: constipation (main therapy), AE: abdominal cramps, flatulence (fermentation), risk of ileum (not enough liq) CI: intestinal atony, obstruction, immobility; no laxative dependence, may take a few days to act fully
Polyethylene Glycol (Macrogol)
not absorbed, local osmotic pressure retains water in colon, laxative effect at low doses and purgative at high doses; I: chronic constipation (predictable effect, directly related to dose and adm. of electrolytes, long administration possible), before colonoscopy/intestinal surgery; AE: flatulence(rare)
Lactulose
synthetic disaccharide (galactose +fructose) not absorbed, having laxative effect through osmosis, broken by colonic bacteria to lactic, acetic, and organic acids, decrease local pH, reduce ammonia absorption, beneficial effect in PT with liver disease (prevent encephalopathy); I: elderly, liver encephalopathy; AE: abdominal pain, flatulence, diarrhea
Sodium/Magnesium sulphate
decrease viscosity of feces by inc. water content; I: rare (before radiology/surgery, though enema (30 min latency) or oral (2-5 hour latency), Sodium sulphate (Glauber salt) was used before as purgative in intoxication but not anymore due to adm of activated charcoal, see adverse effects and contraindications in lecture
Docusate, mineral oil
stool softeners, lubricate and soften stool by adding water and fats, risk of lipid aspiration pneumonia
Irritant purgative agents
irritant action increases accumulation of water and electrolytes in lumen of colon and enhances peristalsis by local reflexes
Senna
irritant purgative, partially absorbed (risk of uterine contraction), passes in milk (diarrhea in baby), 8-10 hour latency, pro kinetic and secretory properties, laxative tea. I: constipation (second line, short adm.), AE: abdominal cramps (each dose), electrolyte imbalance, melanosis coli (reversible, no carcinoma risk), laxative dependence, dehydration, atony of bowel (chronic use), CI: pregnancy, lactation, obstruction
Bisacodyl
6-8 hours (oral) and 30-60 minutes (suppository), small doses decreases water abs in intestine, large doses increases water absorption in intestine; I: constipation (surgery, myocardial infarction, stroke), hemorrhoids, anal tissues, before diagnostic procedures; AE: abdominal pain (each dose), electrolyte imbalance, bowel atony (adm more than 1o days)
Castor Oil
riconoleic acid irritates small intestine mucosa, increasing peristalsis, latency 1-3 Hours, I:empty bower before surgery/diagnostic (not first choice); AE: bad taste, abdominal pain, diarrhea, hydroelectric imbalance; CI: obstruction, intoxication (increases absorption), pregnancy (uterine contraction)
Prucaloprid
new laxative, 5ht4 antagonist with pro kinetic effect; I: women with chronic constipation who do not respond to conventional laxatives (or intolerance)
Linaclotid
new laxative, agonist of guanitlcyclase C, stimulates intestinal secretion of water and chloride; I: irritable colon syndrome w/constipation, chronic constipation (small doses), well tolerated (no adv. effects)
Methylnaltrexone
new laxative, peripheral opioid antagonist, without inhibiting central analgesia, advantage over Naltrexone; I: constipation caused by opioids (palliative tmt.) AE: intestinal perforation (increased in association with chemotherapy)
