Pharm 2 - GI 2

drraythe's version from 2015-04-13 21:56

Cytoprotective agents

Question Answer
what are the 4 types/categories of drugs that are cytoprotective?Antacids, Prostaglandin E analog, Sucralfate, Bismuth subsalicylate
what do you use antacids for (in terms of being a cytoprotective agent)they are used to neutralize the excess acidity (they are weak bases)
what are the NON-systemic antacids?magnesium hydroxide, aluminium hydroxide, calcium carbonate (metal salts) (so. Chalk and MAAL hydroxide)
what should you know about aluminium hydroxide?causes constipation. ALSO binds up phosphate--> hypophosphatemia (aluminum buttplug will damage your electrolyte balance)
what should you know about magnesium hydroxide?laxative in nature (lubed up lax magnum)
which non-systemic antacid causes constipation? which one is a laxative? what else should you know about this?constipation= aluminum hydroxide. laxative= magnesium hydroxide. Can be combined to balance each other out.
hypophosphatemia caused by?aluminium hydroxide
what is the systemic antacid? what are side effects of being systemic?sodium bicarbonat. might cause metabolic alkalosis. Also, liberation of CO2 and distends the stomach--> bleching (or possibly bloating of rumen)
what is the Prostaglandin E1 analog acting as a cytoprotective agent? How is it protective(several ways)? misoprostol. Dec secretion of acid, AND improves mucus secretion AND improves bicarbonate secretion. ALSO improves blood flow and epithelial regeneration
misoprostol is a _________ drug, which means it has what affects?PGE1 ANALOGUE. So does stuff prostaglandins do. Which is dec secretion of acid (seen in other section), improve mucus secretion, inc bicarb secretion, inc blood flow and epithelial regeneration also
Sucralfate MOAat first it is a sulphated disaccharide (aluminium sucrose sulphate). When the drug hits an ACIDIC enviro, sucrose released (from the aluminum hydroxide portion) and then cross polymerizes and binds to exposed anions of damaged GI epithelial cell membranes (polymerizes ulcerated area) and CREATES A PROTECTIVE LAYER!! (from acid, bile, and pepsin). ALSO stim mucus and bicarb secretion. AND acts as a stimulus for the synthesis of local mediators PGs and sulfhydryl ions.
when should you not administer sucralfate?need ACIDIC pH to break apart and then bond to ulcerated areas and exert its effects, so DON'T GIVE WITH ANTACIDS or with ACID SECRETION SUPPRESSORS (H2 receptor antagonists or proton pump inhibitor)
Bismuth subsalicylate does what?ADSORBS E. COLI ENTEROTOXINS . The bismuth and salicylate will be cleaved and the bismuth will produce antibacterial action and coat over the ulcerative tissue. The salicylate will then dec the gastric acid secretions (BIS will fight the Bacteria)
cautions about using bismuth subsalicylate?need to glucoronidate so cautions must be used in cats (cats dont like it when you coat them in pepto bismol)

GI motility stimulators/ antagonists

Question Answer
what are the two groups of drugs which stim GI motility?(1) Cholinergic agonists (2) Prokineticagents
what are the two cholinergic agonists which stim GI motility?Bethanechol, carbachol (last call for the bathroom, comin' through) (oh yeah....and beth makes me wanna shit so bad id even do it in a car)
When should you never use a cholinergic agonist to stim GI motility?in MECHANICAL OBSTRUCTIONS (might lead to rupture of intestine)
what are the prokinetic agents?Metoclopramide, Cisapride, Domperidone
what is the MOA of metoclopramide?inc ACH release from cholinergic neurons--> stim muscarinic receptors of GIT--> prokinetic action (also anti-dopamine-2 from the anti-emetic section)
which prokinetic agent has the broadest spectrum? in what way?cisapride, because the effect is exerted on the whole GI tract (incld colon)
clinical uses of cisapride?bc of it's broad action, it not only is used as a prokinetic agent in general, but is also used to tx constipation with megacolon in cats
tx megacolon in catscisapride
MOA of domperidone?antagonize the dopamine receptor, but has prokinetic properities when acting peripherally
which two groups of drugs dec intestinal motility?anticholinergic drugs and opioid agonists
anticholinergics serve what kinda function in the intestines?antispasmodic and antidiarrheals
what are opioid agonists used for decreasing intestinal motility and secretions? (5)morphine, fentanyl, meperidine(in meperidine category, diphenoxylate, loperamide)
For non-specific acute and chronic diarrhea, which drugs are preferred?opioids
when are opioids contraindicated?in diarrhea due to infection (bc bacteria have more time to prolif bc inc intestinal transit time)
what is Difenoxin?active metabolite of diphenoxylate (which is a Meperidine congener, and meperidine is an opioid)
Loperamide is what?Meperidine congener (meperidine is an opioid) used to dec GI motility. SAFE FOR CATS
what is Paregoric, what is it used for?opioid which is used to dec GI motility--> preferred anti-diarrheal preparation in foals (foals love to eat pares! and they cure diarrhea!)
which opioid is safe for cats?loperamide (cats like to eat lop rabbits)
what are the side effects and contraindications of opiates, and why?increases tone of the sphincter, so intestinal propulsive movement is reduced , thus more time for re-absorption of water= constipation. This prolongs transit time. so DONT use in bacterial diarrheas, because gives bacteria more time to grow
what are the diarrheals she had listed as recommended for cats?Propantheline, Loperamide hydrochloride capsules, Bismuth subsalicylate suspension

GI protectants and adsorbents

Question Answer
what are the 5 mian GI protectant/adsorbants?Bismuth subsalicylate, activated charcoal, cholestyramine, kaolin and pectin
which drug is used in treatment of emergency poisoning? what else should be done?activated charcoal (adsorbs many toxins and poisons). After charcoal is administered, wait a while, and then administer saline laxative to remove the charcoal-poison complex.
what should you know about the dosage of activated charcoal?10:1 charcoal:toxin dosing ratio
what is Cholestyramine? what is it used for?basic anion–exchange resin. usually used to bind to bile salts in the GI tract-- not able to be absorbed systemically, stays in GI. Can also be used to bind up other chemicals.