GI drugs I

Question 1

what is the cause of ulcers

Answer 1

increased acidity or decreased mucosal resistance. caused or promoted by gastric acid

Question 2

where is a peptic ulcer located

Answer 2

in the duodenum

Question 3

what three receptors are present on the parietal cell in the stomach and what do they do?

Answer 3

gastrin, Ach, and histamine. all act to stimulate the K+/H+ ATPase.

Question 4

what does histamine do the cell

Answer 4

increases the formation of cyclic AMP

Question 5

what does gastrin and cholinergics do the parietal cell

Answer 5

increases intracellular calcium

Question 6

where does gastrin come from in the stomach

Answer 6

the antrum

Question 7

where does Ach come from in the stomach

Answer 7

from vagal input

Question 8

where does histamine come from in the stomach

Answer 8

stimulated by both Ach and gastrin

Question 9

define the mucosal protection from acid

Answer 9

there is a pH gradient from very low, to 7 caused by the secretion of bicarbonate. this protects the mucosa from damage. there is reduced bicarb secretion in DU patients.

Question 10

what is the approach to treating ulcers

Answer 10

relief of symptoms, promotion of healing, prevention of complications, prevention of recurrence.

Question 11

what is the treatment plan for ulcers

Answer 11

neutralize acid, decrease acid production, increase resistance

Question 12

antacid therapy

Answer 12

only effective when they can elevate the pH to above 5. stops pepsins damage as well as acidic erosion. best if taken 1 hour after eating when gastrin activity is highest. liquids work better

Question 13

calcium carbonate

Answer 13

reacts slowly with HCl to form calcium chloride and carbonic acid. it is constipating so given with magnesium compounds as laxatives

Question 14

what are the SE of calcium carbonate

Answer 14

milk-alkali syndrome, nephrocalcinosis, rebound acidity, digitalis antagonism d

Question 15

sodium bicarbonate

Answer 15

rarely used because of systemic alkalosis, enhanced effects of amphetamine, quinidine, cinchophen. high sodium content

Question 16

magnesium hydroxide and carbonate

Answer 16

hydroxide is more potent. may cause magnesium intoxication in renal disease.

Question 17

magnesium hydroxide and carbonate SE

Answer 17

diarrhea, hypokalemia, hypermagnesemia, iron deficiency

Question 18

aluminum hydroxide

Answer 18

combines to form al-Cl and water. aluminum is excreted in the feces when it combines with phosphate. this is also useful in protecting the mucosa and doesnt perturb the electrolytes in the body. useful in renal patients.

Question 19

adverse of effects of aluminum chlorides

Answer 19

constipation, phosphate depletion, weakness, anemia, tetany, apnea, delayed gastric emptying, concretions, fecaloma, perforation, peritonitis, encephalopathy. impaired absorption of tetracycline and digoxin.

Question 20

what is defoaming agent and what does it do

Answer 20

within an antacid preparation, claims to disperse the antacid.

Question 21

what is an adverse effect of all antacids

Answer 21

increases the luminal pH

Question 22

antacids cause the decreased absorption of what

Answer 22

dicumarol, L-dopa

Question 23

antacids cause the increased absorption of what

Answer 23

phenothiazines, INH, nalidixic acid, nitrofurantoin, pen G, sulfonamides, premature release of enteric coated tablets.

Question 24

anticholinergics for ulcer treatment

Answer 24

vagotomy effect reduction of HCl secretion. spasmolytic effect.

Question 25

adverse effects of anticholinergics

Answer 25

dry mouth, blurred vision, atony of the bladder, constipation, drowsiness, mental confusion.

Question 26

when are anticholinergics contraindicated

Answer 26

pyloric obstruction, hiatal hernia, peptic esophagitis,

Question 27

what are the common anticholinergics

Answer 27

atropine, propantheline, metantheline bromide.

Question 28

when to administer anticholinergics

Answer 28

30 min before meals and at bedtime.

Question 29

why give the anticholinergics before bed

Answer 29

to reduce nocturnal secretion by vagal block when antacids are not being consumed.

Question 30

H2 blockers agents

Answer 30

cimetidine, ranitidine, famotidine, nizatidine

Question 31

H2 blockers do what

Answer 31

lower acid secretion by blocking the receptor on parietal cells which mediates the release of acid. decreases both basal and food stimulated. can be given prophylactically to reduce stress ulcers.

Question 32

adverse effects of H2 blockers

Answer 32

uncommon. HA, lethargy, confusion, depression and hallucinations.

Question 33

what are the drug interactions for the H2 blockers

Answer 33

P450, theophylline, warfarin, dilatin, lidocaine.

Question 34

H+/K+ ATPase inhibitors agents

Answer 34

omeprazole, lansoprazole, rabeprazole, esomeprazole, pantoprazole, dexlansoprazole.

Question 35

general H+/K+ ATPase inhibitors

Answer 35

these are noncompetitive inhibitors. acitvated by acidic pH. inhibits 90% of 24 hr secretion. better pain relief and healing than the H2-blockers. will even heal H2 refractory ulcers.

Question 36

adverse effects of the H+/K+ ATPase inhibitors

Answer 36

headache gynecomastia, inhibition of 450, gastric hyperplasia. not recommended for long-term use due top carcinoid tumors.

Question 37

what drugs do the H+/K+ ATPase inhibitors interact with

Answer 37

warfarin, diazepam, dilantin

Question 38

what are the agents that decrease the mucosal defenser

Answer 38

NSAIDs, H. pylori, smoking, genetics, stress.

Question 39

hat drugs coat the ulcer/crater

Answer 39

bismuth salts (pepto), sucralfate

Question 40

how do bismuth salts work

Answer 40

in acid they form crystals that precipitate on the ulcer. they have a lower ulcer recurrence rate than H2.

Question 41

how does sucralfate work

Answer 41

aluminum hydroxide complex of sucrose binds to the ulcerated tissue after activation in the acid environment.

Question 42

what are the SE of the coating agents

Answer 42

no adverse effects. constipation, aluminum tox, renal failure.

Question 43

prostaglandin E2 analogs agent

Answer 43

misoprostol

Question 44

misoprostol does what

Answer 44

decreased acid production, increase mucous and bicarbonate secretion. less effective than H2. t

Question 45

what is misoprostol mainly used for

Answer 45

to prevent NSAID induced gastric ulcer

Question 46

adverse effects of misoprostol

Answer 46

transient diarrhea, cannot use in pregnancy

Question 47

drugs that eradicate H pylori

Answer 47

bismuth salts and antibiotics (metronidazole + tetracycline/amoxicillin

Question 48

what is triple therapy for h pylori

Answer 48

a PPI/ranitidine bismuth citrate 2X/day and 2 of amoxicillin/clarithromycin/metronidazole.

Question 49

what is quadruple therapy for h pylori

Answer 49

PPI 2 X tetracycline 4 X bismuth subsalicylate or subcitrate 4X metronidazole 3 X.