GI Flashcards

Question

H2 receptor blockers drugs

Answer 1

-cimetidine (Tagamet) (B), tid-qid -!famotidine (Pepcid)(B), qd-bid -nizatidine (Axid)(B), qd-bid- use in psychiatric hospitals- decreases the weight gain in pts on antipsychotics -All available PO & IV, except nizatidine in PO only -All available generic and OTC (except nizatidine RX only)

Answer 2

-MOA – inhibits the proton pump (H+, K+-ATPase) located in the membrane of the parietal cells and blocks secretion of gastric acid -Indications include: TREATMENT of PUD, GERD, erosive esophagitis, hypersecretory condition, Zollinger-Ellison syndrome -Should only be used for max 8 weeks for short term tx of active disease -may be used longer for maintenance therapy at lower dose -Can also use to PREVENT NSAID-induced ulcers -Kinetics - administered as inactive pro-drugs; short half life - but DOA up to 24 hours -Can give qd-bid -Must take 30-60 mins prior to meal so drug is available before acid pump is activated by food -If giving QD, better to give before the dinner meal

Answer 3

-fairly well tolerated -minor GI effects like diarrhea and abdominal pain -May cause headache -May decrease B12 absorption -May increase risk of C. dificile diarrhea, esp. if taken with certain antibiotics -New reports of increase risk of hip fractures with long-term use

Answer 4

-Caution if given in conjunction w/ drugs that REQUIRE an acidic environment for absorption (atazanavir, ketoconazole) -All are substrates of CYP450 system -Omeprazole is a CYP2C19 inhibitor. Significant DDI with clopidogrel -> decrease in antiplatelet activity!!!

Answer 5

-omeprazole* (Prilosec)(C)- Combo w/ Na bicarb (Zegerid) -lansoprazole (Prevacid)(B) -rabeprazole (Aciphex)(B) -pantoprazole* (Protonix)(B) - less DDI - used in hospitals a lot -esomeprazole (Nexium) (B) -dexlansoprazole (Kapidex) (B) -* Available generic -All PPIs are available PO, Protonix and Nexium are also available as IV

Answer 6

-(Carafate)(B) MOA – it is a viscous polymer that adheres to ulcers and epithelial cells, inhibits pepsin catalyzed hydrolysis of mucosal proteins and stimulates prostaglandin synthesis -formation of protective barrier of GI tract- doesnt treat -> just coats -Works best in pH 1-2. -Used for PUD (duodenal), but less effective than H2 blockers or PPI -May be used to prevent bleeding from stress-related gastritis. -ADRs - rare - not absorbed, may cause constipation -Dose: 1 gm QID (1 hr ac & hs) -Don’t take with antacids (± 2 hr)

Answer 7

-Misoprostol (Cytotec) (X) ! -MOA – prostaglandin E1 analog, inhibits gastric acid secretion and promotes secretion of mucus and bicarbonate. -Primarily used for prevention of ulcers in pts on long-term NSAID therapy. VERY EFFECTIVE. Must be given BID-QID with food for the duration of NSAID therapy. -ADRs include N,V,D, abdominal cramping, flatulence and headache

Answer 8

-Single drug therapy rarely effective -Multi-drug therapy must be used -Use either proton-pump inhibitor OR H2 blocker + two or more of the following: amoxicillin, bismuth, clarithromycin, metronidazole, tetracycline or levofloxacin -!!!Preferred regimen: PO triple therapy for 14 days with: -PPI BID (continue for 4-6 wks) -Clarithromycin BID -Amoxicillin 1 g BID OR metronidazole 500 mg BID

Answer 9

-Can occur during trauma or critical illness usually due to inadequate perfusion. -Hypoperfusion results in increased permeability, decreased pH and impaired mucosal defenses

Answer 10

-Acute Risk Factors: -mechanical ventilation > 48 hours -Coagulopathy -Renal failure -Hypotension and septic shock -High-dose steroids -Traumatic Brain Injury and Spinal Cord Injury -Potential Risk Factors concurrent NSAID use -Concurrent or recent steroid use -PMH of GI bleed -PMH of PUD -PMH of gastritis

Answer 11

-H2 receptor blockers -Most clinical evidence -Use in patients with acute risk factors and critically ill -Consider in patients with potential risk factors -PPIs -No more efficacious than H2 receptor blockers -More expensive -Reserve for pts with PMH of UGIB or GERD -Sucralfate – RARELY used

Answer 12

-Laxatives stimulate intestinal peristalsis and increase movement of material through the bowel. They increase intestinal transit time and facilitate defecation -Used to treat constipation, evacuate bowel prior to surgeries or diagnostic procedures or to eliminate drugs or poisons from the gi tract in cases of overdoses or poisonings -4 categories of laxatives: -Bulk-forming laxatives -Osmotic laxatives -Stimulant laxatives -Surfactants (stool softeners)

Answer 13

-MOA -indigestible hydrophilic substances that resemble natural dietary fiber -Induce H20 retention in gi lumen and increase mass of intestinal material –> causes mechanical distension of intestinal wall and stimulates peristalsis -Take 1-3 days to see effect -depends on how much water you drink -if you dont take it with water it can treat diarrhea - good for IBS combo -Ex: psyllium (Metamucil), methylcellulose (Citrucel), polycarbophil (Fibercon), bran -Must take w/ a lot of H20, if not will get constipation

Answer 14

-MOA – attract and retain H20 in the lumen, increase intraluminal pressure and stimulate peristalsis. -May be taken orally in liquid or chewable tablets or as enemas. -Rapid acting. -Most often used for bowel evacuation prior to surgery, dx exams or for drug overdose or poisonings

Answer 15

-MAGNESIUM SALTS- INSTANT BM - drink it on the toilet -citrate (Citroma), -sulfate (Epsom salts) -oxide (milk of magnesia) – may be used in low doses to prevent constipation in pts taking opioids -SODIUM PHOSPHATE -LACTULOSE - used in chronic hepatitis encephalopathy (unique MOA which converts ammonia to ammonium ion) -POLYETHYLENE GLYCOL-ELECTROLYTE SOLN (miralax)- electrolytes are isotonic, so that there is no electrolyte imbalance

Answer 16

-MOA – act directly on intestinal mucosa (irritant) to alter fluid secretion and stimulate peristalsis -ADRs - n,v,d, loss of normal bowel function with excessive use, malabsorption of nutrients -Natural (plant derived) or synthetic -senna (Senokot) – PO, PR (onset 6-10hr for PO, 1-2 hr for PR) -cascara sagrada – from dried bark (onset 6-12hr) -bisacodyl (Dulcolax) – PO, PR (onset 6-12 hr for PO, 15-60 min for PR) -castor oil (ricin) – PO, (onset 2-6 hr); causes severe peristalsis, enough to induce uterine contraction during pregnancy

Answer 17

-Aka stool softeners. MOA – facilitate incorporation of H20 into fatty intestinal material and thereby soften the stool. -Useful in pts w/ hemorrhoids or when straining should be avoided (post surgery) -Anesthesia causes constipation. -ADRs – bitter taste, mild cramping, diarrhea, laxative dependence with long term use -Examples: -Docusate (Colace) PO - onset is 1 to 3 days -glycerin suppositories -mineral oil

Answer 18

-Diarrhea is often a symptom of an underlying disease. If bacterial in origin: -let diarrhea run its course and allow bacteria to be expelled by body (self-limiting) -attack causative bacteria with antibiotics -most serious side effect of diarrhea is dehydration and subsequent electrolyte disturbances -> fluid replacement is necessary, especially in the very young and very old. (Pedialyte, Rehydralyte)

Answer 19

-all morphine and meperidine related compounds -Most efficacious antidiarrheals! -MOA – induces a segmental contraction which prevents normal peristalsis -Choose opioid which selectively activates intestinal opioid receptors with little CNS effect on opioid receptors -diphenoxylate + atropine (Lomotil) PO, Schedule 5 drug - diphenoxylate is the opioid component, Related to meperidine -about 10x more potent than morphine as anti-diarrheal -Atropine prevents abuse of diphenoxylate and assists via its anticholinergic SEs -loperamide (Imodium) 40x more potent than morphine as antidiarrheal -Available OTC -**do not use in c. dificile colitis**

Answer 20

-Locally acting drugs – either adsorb H20 and toxins or inhibit intestinal secretions. Not as effective as opioids as antidiarrheals, but can be used safely in infectious diarrhea incl C. dificile. -bismuth subsalicylate (Pepto-Bismol, Kaopectate) – Contraindicated in ASA allergy -Inhibits intestinal secretions -Good for infectious diarrhea -Also for prevention and tx of traveler’s diarrhea -Can cause black tongue and stools -activated charcoal- not recommended- it binds everything and inactivates

Answer 21

-flouroquinolones, azithromycin and rifaximin (Xifaxin) are effective for traveler’s diarrhea -Metronidazole, vancomycin and/or fidaxomicin for C. dificile colitis

Answer 22

-not helping on cellular level -helping on a pH level -Calcium carbonate causes rebound acid -use for mild and immediate relief -not prolonged -there are a lot of DDIs for for antiacids -> take it 2 hrs from other meds

Answer 23

-(lactobacillus, Activia, Florastor) -Can be beneficial for prevention and tx of some types of diarrhea (including antibiotic-induced diarrhea)

Answer 24

-antibiotics -probiotics -locally acting drugs -bismuth subsalicylate -activated -opoids -octreotide

Answer 25

-(Sandostatin) SQ -MOA - inhibits motility and fluid secretion. -Used for diarrhea caused by tumors of the gi tract and AIDS-related diarrhea -For Esophageal Varices – MOA is inhibits mesenteric vasodilation -Endoscopic treatment is usually first line -Octreotide used as adjunct to prevent re-bleeding after endoscopic procedures -Continuous IV for 2-5 days -ADRs include QT prolongation, Bradycardia, HTN and flushing. Must monitor patient

Answer 26

-MOA - directly stimulates the CTZ and also irritates gastric mucosa -Used to induce vomiting in poisonings for children and adults -CI in semi comatose or unconscious pts, severely inebriated pts, seizures, shock or in loss of gag reflex. DO NOT use after ingestion of gasoline, kerosene, volatile oils or other caustic substances -ADRs – depression, drowsiness, bradycardia, hypotension, cardiac arrhythmias and potentially fatal myocarditis with excessive doses

Answer 27

-Emesis initiated by a nucleus of cells in the medulla called the vomiting center -Vomiting center activated by: -vagal impulses from the gut via the solitary tract nucleus -the Chemotrigger zone (CTZ) -cerebral cortex -vestibular apparatus -Receptors involved in emesis -Gut: 5-HT3, M1 -Solitary tract nucleus: 5-HT3, D2, M1, H1 -Chemotrigger zone (CTZ): 5-HT3, D2, M1 -CTZ also activated by blood-borne substances, incl chemotherapy agents -Vestibular apparatus: M1, H1

Answer 28

-H1 receptor antagonists – antihistamines -Anticholinergics -Serotonin (5HT3) receptor antagonists -Dopamine (D2) receptor antagonists

Answer 29

-MOA - block peripheral stimulation of the H1 receptor from the vestibular apparatus to the vomiting center and in the solitary tract nucleus. They are most effective in relieving nausea and vomiting associated with motion sickness -dimenhydrinate (Dramamine)(B) -diphenhydramine (Benadryl) (B) -meclizine (Antivert) (B) – used for vertigo- hangover -ADRs – drowsiness, headache, blurred vision, dry mouth, constipation

Answer 30

-MOA - decrease secretions, decrease GI motility, and blocks muscarinic stimulation at the gut, STN, vestibular apparatus and/or CTZ -scopolamine patch -Used to prevent motion sickness. Specifically blocks M1 receptors at the vestibular apparatus. -Apply before cruise, drive, flight -Lasts for 3 days -1 patch behind an ear every 3 days -ADRs – disorientation, drowsiness, headache, blurred vision, dry mouth, constipation

Answer 31

-MOA - primarily decrease GI motility by blocking muscarinic stimulation of the gut and CTZ. Also works at STN. -Primarily used as antispasmodics in gi disorders, esp. for irritable bowel syndrome -hyoscyamine (Levsin) (C) -dicyclomine (Bentyl) (B) -hyoscyamine + atropine + phenobarbital- self limiting -decrease abuse

Answer 32

-MOA - block 5-hydroxytryptamine (Serotonin) receptors (5-HT3 receptors are found in the gut, solitary tract nucleus and CTZ) -ondansetron (Zofran) (B) PO, IV -granisetron (Kytril) (B) PO, IV -dolasetron (Anzemet) (B) PO, IV -palonosetron (Aloxi) (B) IV only -ADRs for all – headache, drowsiness, diarrhea and rarely bradycardia -All are used to PREVENT chemotherapy induced nausea and vomiting -must be given prior to or immediately following administration of chemo drug -Other FDA indications include prevention and/or tx of post-op nausea and vomiting and prevention of radiation-induced nausea and vomiting -These indications vary amongst the different agents

Answer 33

-MOA – primarily blocks dopamine (D2) receptor at the CTZ, thereby decreasing stimulation of the vomiting center, also block (D2) receptor in the solitary tract nucleus -As a class, PTZ have antiemetic, antipsychotic, anticholinergic, antihistamine, antitussive, and sedative properties -prochlorperazine (Compazine) (C) -promethazine (Phenergan) (C) -trimethobenzamide (Tigan) (C) -ADRs - sedation, confusion, anticholinergic, orthostatic hypotension, hematologic SEs, and Extrapyramidal SEs -Dystonia- uncontrolled movements -dyskinesia -these are good for people that cant keep meds down -> suppository and injectables

Answer 34

-(reglan) (B) -MOA – same as PTZ except it also can inhibit vomiting by blocking 5HT3 receptors in gut and CTZ. Also a prokinetic agent. -Available PO/INJ -ADRs – CNS depression, restlessness, hematologic SEs, potentiates anticholinergic SEs, EPS, Rarely causes suicidal ideation and seizures

Answer 35

-(Marinol) (C) – oral formulation of tetrahydrocannabinol (THC) (CIII) -Approved for the treatment of chemotherapy induced nausea and vomiting and as an appetite stimulant in AIDS anorexia -MOA – inhibition of endorphins in brain’s emesis center. Also, stimulation of cannabinoid receptor (CB1) within CNS may contribute to its antiemetic effects

Answer 36

-emend (B) -FDA approved use – used in combo with other antiemetics for prevention of acute and delayed n/v assoc with initial and repeat courses of highly emetogenic chemotherapy -MOA – selective high-affinity antagonist of human substance P/neurokinin 1 receptors. Has little or no effect on other receptors involved in emesis pathways

Answer 37

-(Varubi) (B) -FDA approved use – used in combo with other antiemetics for prevention of acute and delayed n/v assoc with initial and repeat courses of highly emetogenic chemotherapy -MOA – selective high-affinity antagonist of human substance P/neurokinin 1 receptors. Has little or no effect on other receptors involved in emesis pathways

Answer 38

-phosphorated carbonated soln - OTC -Used to relieve nausea caused by intestinal flu, stomach flu or food & drink indiscretions -MOA – direct local action of the GI tract that reduces smooth muscle contraction -Avoid in DM b/c of high sugar content

Answer 39

-Used to treat gi motility disorders – (GERD, gastroparesis, IBS) -MOA - Increase gi motility in esophagus, stomach and small intestine -Examples: -metoclopramide (Reglan)– blocks D2 and 5HT3 receptor -lubiprostone (Amitiza) (C) – prostaglandin E1 analog that activates chloride channels in the gut. This leads to increased intestinal fluid secretion and improved motility. Only approved for adult females with IBS and constipation

Answer 40

-Constipation predominant: adequate hydration, dietary fiber, bulk-forming laxatives, occasional use of osmotic laxatives, prokinetics, and lubiprostone (Amitiza) -Abdominal pain, spasms: Anticholinergic antispasmodics and fiber-based products -Diarrhea: Antidiarrheals -Bloating and gas: Simethicone -Tx also aimed at avoiding triggers like excess caffeine, fruit intake, carbonated drinks and gum -NSAIDs and Antidepressants (esp TCAs) may be used to treat pain associated with IBS

Answer 41

-(lotronex) -MOA: potent and selective 5-HT3 receptor antagonist -approved for treatment of WOMEN with Irritable Bowel Syndrome (IBS) whose predominant bowel symptom is diarrhea and who are non-constipated. -ADR: -Hypertension -Allergic rhinitis -Throat and tonsil discomfort and pain -Bacterial ear, nose, and throat infections -Nausea -Gastrointestinal discomfort and pain -Abdominal discomfort and pain -Gastrointestinal gaseous symptoms. -Viral gastrointestinal infections -Dyspeptic symptoms -Abdominal distention -Hemorrhoids -Sleep disorders -Depressive disorders

Answer 42

-(Viverzi) -MOA: mu-opioid receptor agonist; eluxadoline is also a delta opioid receptor antagonist and a kappa opioid receptor agonist. It decreases pain and potentially mitigates the constipating effect of unopposed mu agonism. -specifically indicated in adults for the treatment of irritable bowel syndrome with diarrhea. -ADR -constipation -nausea -abdominal pain

Answer 43

-(Xifaxan) -MOA: emi-synthetic derivative of rifampin and acts by binding to the betasubunit of bacterial DNA-dependent RNA polymerase blocking one of the steps in transcription. This results in inhibition of bacterial protein synthesis and consequently inhibits the growth of bacteria. -indicated for the treatment of of irritable bowel syndrome with diarrhea (IBS-D) in adults. -ADR: -ALT increased -nausea

Answer 44

-(Linzess) -MOA: Activation of GC-C results in an increase in both intracellular and extracellular concentrations of cyclic guanosine monophosphate (cGMP). -Elevation in intracellular cGMP stimulates secretion of chloride and bicarbonate into the intestinal lumen, resulting in increased intestinal fluid and accelerated transit -Linzess is specifically indicated for the treatment of adults with irritable bowel syndrome with constipation and for adults with chronic idiopathic constipation -ADRS -diarrhea -abdominal pain -flatulence -abdominal distension

Answer 45

-MOA; local anti-inflammatory action by COX inhibition -for colitis or chrons colitis -ADRs: Fever, fatigue, headache, n/v/d, SJS, BMS -Examples: -Sulfasalazine (Azulfidine): combination of sulfapyridine and 5-ASA. ADRs include n/v and headaches, orange pee -Mesalamine (Pentasa, Lialda): -5 – ASA only, no sulfapyridine. Can use in sulfa allergic patients. -Different formulations available to target certain sites in GI tract -Better tolerated than sulfasalazine -Also available as suppository (Canasa) or enema (Rowasa) – Can use both for additive effects -Osalazine (Dipentum) – prodrug of mesalamine. Produces lower plasma concentration and higher delivery of drug to colon. Also better tolerated than sulfasalazine

Answer 46

-PO as short term induction therapy and for bridging to MAB, AZA/6-MP and/or MTX. -More effective than aminosalicylates in inducing remission. -Prednisone is most commonly used agent. -IV short-course for exacerbations -Enemas for local effect in colon in pts with UC not controlled with mesalamine -use these to bridge people onto a diff med

Answer 47

-MOA – Induce T-cell apoptosis -Can help induce and maintain remission in 2/3 patients with IBD and reduce steroid dependancy -ADRs: BMS, increased infections, pancreatitis, cancer -you get symptoms outside of GI effects (joint, skin) and then you can tell if your having a flare -Examples: -Azathioprine (Imuran) -6-mercaptopurine (Purinethol) -other- cyclosporine, methotrexate

Answer 48

-(Neoral) -immunosuppressants -Used for UC -For severe cases or for bridging to other agents take effect -Monitor levels, CBC, lipids, renal function and BP

Answer 49

-immunosuppressants -for induction or maintenance of remission in CD -Usually considered if refractory to azathioprine and 6-MP -Monitor CBC and LFTs -**All of the immunosuppressants increase risk of infection, including atypical infections**

Answer 50

-Precautions/Black box warning: -Infections (including TB and serious opportunistic infections) can occur, esp if used in combo w/ other immunosuppressants. Screen for latent TB prior to initiating therapy. -Lymphoma risk -Indications: UC, CD, RA. Mostly used to induce and maintain remission and steroid sparing. For CD – particularly useful for reducing fistulas and extraintestinal complications -ADRs: Infection risk, Lymphoma risk, infusion or local injection site reactions, fatigue, URTI -Examples: -Infliximab (Remicade) (IV infusion)- comes from a mouse -Adalimumab (Humira) (SC) -Certolizumab pegol (Cimzia) (SC)

Answer 51

-Smoking can benefit UC but worsen CD -Surgery can be curative in UC -Steroids have similar role for both UC and CD -Aminosalicyclates are backbone for mild to moderate UC, reserving immunosuppressants for more severe cases -Aminosalicyclates main benefit in CD if disease confined to colon -Immunosuppressants and MABs have similar role in UC and CD (induce and maintain remission and reduce need for steroid) -MABs used more often in CD, also good for fistulas in CD. Infliximab is primary agent for UC, whereas all 3 MABs are used in CD -Alternatives to immunosuppressants: Cyclosporine for UC, MTX for CD -Antibiotics: Metronidazole and Ciprofloxacin are commonly used in CD for perianal fistulas

Answer 52

-(creon, pancrease, ultrase) -Indications: Used primarily for pancreatic insufficiency -MOA: product disintegrates into trypsin, amylase and lipase in order to break down proteins, carbohydrates and fats -DDIs: antacids may decrease efficacy of pancrelipase; pancrelipase decreases iron absorption -Dosing: should be dosed with all meals and snacks. Snack dose is half the meal dose -Can combine with H2 blockers and PPIs

Answer 53

What other questions might you ask this patient? Why is he at risk for H. pylori induced PUD? Which individual medications would you avoid in this patient What therapy would you recommend for patient and why? Write the RX for the treatment of PUD for this pt. -smoke? drink? NSAIDS? -avoid cimetidine in elderly -PPI, 1 tablet daily, famotidine 20mg 1-2xday -h pylori at least 2 antibiotics

Answer 54

What class of antiemetics is preferred to prevent chemotherapy-induced n/v? Which antiemetics can be used for the continued treatment of n/v post-chemo? Write a RX for an antiemetic for the pt to use at home on a PRN basis? -5HC3 -pre therapy -post chemo- prothylperizine, pheno, steroids, ativan, PKN1

GI Flashcards

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