Mod 3: Lecture 1 Flashcards
Exam 1
1
Q
Divisions of the GI system
A
Upper
Lower
Hepatobilliary system
2
Q
Divisions of the GI system: Upper
A
Esophagus
Stomach
Small intestine
3
Q
Divisions of the GI system: Lower
A
Large intestine (colon)
Appendix
Rectum
4
Q
Divisions of the GI system: Hepatobilliary system
A
Liver, gallbladder, pancreas
5
Q
Neural controls: Sympathetic nervous system- what does it decrease?
A
Decreases secretion and peristalsis
6
Q
Neural controls: Parasympathetic nervous system- what nerve
A
Vagus nerve
7
Q
Neural controls: Parasympathetic nervous system- does what?
A
Increases secretion and peristalsis
Tasting food
8
Q
Neural controls: Sympathetic nervous system- what does it stimulate?
A
Stimulates vasoconstriction in the mucosa
9
Q
What stomach enzyme digests proteins?
A
Pepsin
10
Q
What does HCI do in the stomach?
A
HCl acid activates enzymes, breaks up food, kills germs
11
Q
What protects the stomach walls?
A
Mucus protects stomach wall
12
Q
What is an issue with the stomach?
A
limited absorption
13
Q
Lower esophageal (cardiac) sphincter is where:
A
between esophagus and stomach
14
Q
Pyloric sphincter is where:
A
between the stomach and duodenum
15
Q
What protects gut wall of small intestine?
A
Mucus
16
Q
What does small intestine do?
A
Absorbs nutrients and most water
17
Q
What in small intestine digests proteins, what digests sugars? What digests nucleotides?
A
Peptidase digests protein
Sucrases digest sugar
Nucleotidases and phosphatases digest nucleotides
18
Q
What does large intestine do?
A
Reabsorbs some water and ions
Forms and stores feces
19
Q
What does rectum do?
A
Stores feces prior to elimination through anus
20
Q
What organ completes digestion?
A
small intestine
21
Q
Chyme
A
acid fluid passes partially digested food from stomach to small intestine
22
Q
What are the digestive juices stomach makes:
A
Hydrochloric acid ~
Pepsin ~
Gastric lipase ~
Intrinsic factor ~
Mucus ~
23
Q
How does HCI work?
A
is secreted by parietal cells,
protein digestion, kills bacteria
24
Q
What does gastric lipase do?
A
Gastric lipase ~ fat digestion
25
What does intrinsic factor do?
Intrinsic factor ~ B12 absorption in small intestine
26
What is mucus stimulated by?
Mucus ~ Protects stomach lining,
stimulated by prostaglandins,
mucosal barrier, gastric mucosal blood flow
27
Stomach absorption of nutrient? What is absorbed in the stomach?
No nutrients, only prepares for absorption.
ETOH
28
Pyloric sphincter- what does it prevent?
Prevents reflux of bile from the small intestines
29
Pyloric sphincter
a muscular valve at the bottom of the stomach that controls the flow of food from the stomach into the small intestine
30
What is the initial part of the small intestine?
Duodenum
31
Emesis- what kind of action?
Involuntary or voluntary
32
How is emesis protective?
Drug OD
Infection
33
What is emesis associated with? What are examples?
Association with severe pain
ex;
Migraines
Renal calculi
34
What does emesis involve coordination with?
Coordination via medulla oblongata
35
Coordination via medulla oblongata for emesis include what two groups?
1. Vomiting center (VC) activation
2. Chemoreceptor Trigger Zone (CTZ)
36
What is needed for Vomiting center (VC) activation?
Direct acting stimuli
37
What are examples of direct acting stimuli in VC activation?
Fear ~ cerebral cortex
Smell/sight or pain ~ sensory organs
Motion sickness ~ vestibular apparatus of inner ear (cranial nerve VIII)
38
Fear is involved with what part of the brain?
Fear ~ cerebral cortex
39
Smell/sight or pain is involved with what part of the brain?
Smell/sight or pain ~ sensory organs
40
Motion sickness is involved with what part of the brain?
Motion sickness ~ vestibular apparatus of inner ear (cranial nerve VIII)
41
The Chemoreceptor Trigger Zone (CTZ) requires what kind of stimuli?
Indirect stimuli
42
Indirect stimuli for the CTZ include what?
Gut activation
Drugs, toxins, chemicals in the blood
43
Vomitus; What is it and does it aid with?
Contents vomited
Aids w/ ID of underlying cause
44
Hematemesis:
vomitus with blood
45
What kind of appearance does vomit with blood have? Why?
Brown, granular appearance ~ coffee grounds
It is Partially digested protein
46
Why does hematemesis occur?
Blood irritation to GI mucosa --> attempts to expel
47
Diagnosis is capable of causing upper GI bleed include
Gastric ulcers
Esophageal varices
GIB gastro intestinal bleeding
48
Bile containing vomitus is what color?
Yellow- or green-colored
49
Bile containing vomitus
Why does it occur?
Can occur from GI tract obstruction
Liver biliary
50
Fecal containing vomitus (throwing up poop); how does it appear? Why?
Deep brown color of
May indicate content from lower intestine, possibly fecal
51
Fecal containing vomitus (throwing up poop) diagnosis include:
Intestinal obstruction
Impacted feces
cancer
52
Undigested food in vomitus occur because:
Impaired gastric emptying
Pyloric stenosis
53
Projectile Emesis
Vomitus exits with force
54
What are qualities of projectile emesis?
Often sudden
Subsequent excessive vomitus with each attack
Are not preceded by nausea
55
Associated conditions of projectile vomitting? what is the main one?
Intestinal obstructions
Delayed gastric emptying
**↑ ICP/Head injury**
Poisoning
Overeating
Neurologic lesions – tumors, aneurysms- involving brainstem
Pyloric stenosis
56
Complications of Emesis include:
Exhaustion
Fluid imbalances
Electrolyte imbalances
Acid–Base imbalances -?
Aspiration
57
What kind of acid base imbalance from vomitting?
metabolic alkalosis
acidosis for diarrhea
58
Procedures for management of Emesis may include?
PMH
PE
Blood chem
59
What are treatment goals for management of emesis?
Cessation of vomiting
Maintaining hydration (PO/IVF)
Restoring acid–base balance
Correcting electrolyte alterations
60
For cessation of vomiting, what can be given?
Antiemetics
61
Antiemetics include
5HT antagonists
Metoclopramide
Antihistamines: Dimenhydrinate, Meclizine, Diphenhydramine
Muscarinic antagonist: scopolamine
62
Best management of motion sickness
Most effective to treat prophylactically
63
Scopolamine is what kind of drug?
Muscarinic antagonist
64
How does Scopolamine patch work?
TD patch behind the ear
Apply 4h prior to travel
65
What are examples of Antihistamines for motion sickness?
Dimenhydrinate & meclizine
66
Which is most effective for managing motion sickness?
Scopolamine
67
Receptors & Agents Involved in Emesis
What classes of drugs are involved in emesis control?
1. Serotonin antagonists
2. Anticholinergics
3. Antihistamines
68
5HT3 receptor Antagonists (serotonin receptor antagonists)- What is the prototype?
Ondansetron (Zofran)
69
What class in Ondansetron (Zofran)?
Class: Serotonin antagonists
70
What is the mode of action of Ondansetron (Zofran)?
Blocks type 5HT-3 serotonin receptors in the CTZ & on afferent vagal nerves upper GIT
71
What is Ondansetron (Zofran) used for?
CINV
Radiation
Anesthesia
72
How is Ondansetron (Zofran) administered?
PO, IM or IV, ODT
73
What is Ondansetron (Zofran) augmented with?
Augmentation with GCs
74
How should Ondansetron (Zofran) for a procedure (chemo)?
Give before to prevent:
CINV 30min prior
Anesthesia 1h prior
Radiation TID
Postop N/V
75
COmmon adverse effects of Ondansetron (Zofran)?
HA, diarrhea, dizziness
76
What is a serious adverse effect of Ondansetron (Zofran)?
QT prolongation
↑ risk of torsades de pointes
Avoid in long QT syndrome
77
When should Ondansetron (Zofran) be avoided?
Avoid in long QT syndrome
78
What does Ondansetron (Zofran) not cause?
⍉ DA blockade = ⍉ EPS
79
Precautions to take for Ondansetron (Zofran)?
Electrolyte imbalances
HF
Brady dysrhythmias
**QT prolonging drugs**
80
Metoclopramide (Reglan) is what class of drug?
Prokinetic agent/Dopamine antagonist
81
Since Metoclopramide (Reglan) is a Prokinetic agent/Dopamine antagonist, what does that mean?
Increase GI tone & motility
82
What is the mode of action of Metoclopramide (Reglan) ?
Blockade of Dopamine & serotonin receptors in CTZ
Increases Ach actions = increase in upper GI motility
83
Metoclopramide (Reglan) causes Blockade of Dopamine & serotonin receptors in CTZ, what can this be used for?
CINV & post-op N/V
chemotherapy-induced nausea and vomiting
84
Since Metoclopramide (Reglan) increases acetylcholine actions and increases upper GI motility what does that mean?
Stimulates motility of UGI tract & accelerates gastric emptying (rest & digest)
85
Metoclopramide (Reglan) Stimulates motility of UGI tract & accelerates gastric emptying (rest & digest); What does this mean it can be used for?
Diabetic gastroparesis
Suppression of gastroesophageal reflux
86
How is Metoclopramide (Reglan) administered?
PO
IV
87
When should Metoclopramide (Reglan) be administered for Diabetic gastroparesis ? How?
PO
Diabetic gastroparesis (10mg PO 30 min before meals & HS x 2-8 wks)
88
When should Metoclopramide (Reglan) be administered for gastroesophageal reflux? How?
PO
Suppression of gastroesophageal reflux (10-15mg PO 30 min before meals & HS for max 12 wks)
89
What is Metoclopramide (Reglan) given IV for? When?
CINV & post-op N/V ~ 30min prior
90
Adverse effects of Metoclopramide (Reglan)
Sedation & diarrhea- Common in High Dose therapy
Irreversible tardive dyskinesia
91
Since Metoclopramide (Reglan) causes tardive dyskinesia, what does this?
Keep TX brief!!!
92
What is Metoclopramide (Reglan) contraindicated in?
GI obstruction, perforation, or hemorrhage
as per ↑ GI motility
93
Key Nursing Responsibilities with Metoclopramide Administration:
Assess for Parkinsonian sx – diff speaking, swallowing, loss of balance, pill rolling, rigidity, tremors, dystonia and tardive dyskinesia – uncontrolled rhythmic movements of mouth, face, exts, lip smacking, puffing cheeks
94
What is the mode of action of scopolamine?
Suppressing nerve communication in neuronal pathway that connects the vestibular apparatus of inner ear to the vomiting center
95
What is released during vestibular system activation?
Acetylcholine
Vestibular apparatus --> XX inner ear XX --> VC
96
Scopolamine is used for what?
Most effective drug for preventing motion sickness
End Of Life
Scopolamine > antihistamines
97
How is Scopolamine administered?
Oral, Sq, transdermal
TD patch applied behind ear
Q72h
98
Common Adverse effects of Scopolamine?
Dry mouth, blurred vision, drowsiness
99
What are more severe but less common effects of scopolamine?
Urinary retention, constipation, disorientation
100
Antihistamine drugs include?
Dimenhydrinate (Dramamine)
Meclizine (Antivert)
101
Why are antihistamines classified as anticholingerics?
Classified as anticholinergic because block receptors for acetylcholine (muscarinic cholinergic)
102
Why are antihistamines mode of action?
Blockade of histamine (H1) & muscarinic receptors in the neuro pathway connecting inner ear to VC
103
What can antihistamines be used for?
Use: motion sickness
104
What are adverse effects of antihistamines?
H1 blockade
Muscarinic blockade
105
Adverse effects of antihistamines: H1 blockade means it leads to what symptoms?
Sedation
106
Adverse effects of antihistamines: muscarinic blockade means it leads to what symptoms??
Dry mouth, confusion, hallucinations
Blurry vision, urinary retention, constipation
107
Gastritis
Inflammatory disorder of the gastric mucosa lining
108
What does gastritic do to stomach lining?
Gastric lining red, edematous
109
What occurs when the stomach lining is damaged?
Ulceration and bleeding when the mucosal barrier is damaged, or circulation compromised
110
What are common causes of gastritis?
Drugs: *NSAIDs, Glucocorticoids
*H. pylori, physiologic stress-related mucosal changes
Alcohol, metabolic disorders (eg renal failure – uremia)
111
Symptoms of acute gastritis include?
Sx: vague abd pain, epigastric tenderness, bleeding
112
Who does Chronic gastritis tend to occur in?
Tends to occur in older adults
113
What does Chronic gastritis cause?
Causes gastric mucosal atrophy, epithelial changes
114
What are two types of chronic gastritis?
2 types: immune (T-cell toleranace, auto Abs) vs
non-immune (same causes as acute)
115
What is immune cause of chronic gastritis?
T-cell toleranace, auto Abs)
116
What is nonimmune cause of chronic gastritis?
non-immune (same causes as acute)
117
What does chronic gastritis put you at an increased risk for?
Increased risk of duodenal ulcers, gastric cancer
118
What is effects with chronic gastritis?
Absorption of nutrients and enzymes are affected
119
How to treat chronic gastritis without medicine?
Eat small meals, soft, bland diet, avoid etoh & ASA
120
What is treatment of chronic gastritis?
Tx: GI meds, abx for h.pylori, Vit B12
121
Helicobacter pylori (H. Pylori) what kind of bacteria?
Gram neg bacteria adapts to acidic stomach by secreting toxins
122
How does Helicobacter pylori (H. Pylori) survive in the stomach?
Gram neg bacteria adapts to acidic stomach by secreting toxins
123
What does Helicobacter pylori (H. Pylori) do?
Invades the gastric mucosa lining, causing inflammation.
124
What is important about the shape of H.pylori?
Spiral shape allows them to penetrate mucosal barrier, where they are protected by mucus, interfering in the immune response so they are not destroyed.
125
What causes stomach irritation in H.Pylori? What else does it cause?
The combination of stomach acid and H. pylori cause irritation, resulting in sores and ulcerations.
126
How long is H.pylori in the gut?
Can remain in gut for decades
127
What are signs and symptoms of Helicobacter pylori (H. Pylori)?
S/sx: Excessive burping, bloating, n/v, anorexia, unexplained weight loss, foul breath
128
How is H.Pylori assessed?
Tested through stomach lining endoscopic biopsy, breath, serologic, stool tests
129
What does H.Pylori treatment consist of in general?
Combo of antibiotics prescribed (at least 2) to reduce risk of resistance (10-14 days)
130
What antibiotics are used to treat H.pylori in combination? - name 4
Proton Pump Inhibitor (PPI) or HR2A blocker
Mucosal protectants
Amoxicillin (Pcn)
Clarithromycin (macrolide)
131
What antibiotics are used to treat H.pylori in combination? - name 3
Bismuth compounds (bismuth subsalicylate - main ingredient in Pepto-Bismol)
Tetracycline
Metronidazole
132
What does amoxicillin do to treat H.pylori?
Kills H. pylori by disrupting cell wall, highly sensitive
133
Where does amoxicillin work highest?
Works highest at a neutral pH
134
How are amoxicillin effects enhanced?
Effects enhanced by reducing gastric acidity with an antisecretory agent
135
What is the most common side effect of amoxicillin?
Most common side effect is diarrhea
136
What does Clarithromycin (macrolide) do for H.pylori treatment?
Suppresses growth of H. pylori by inhibiting protein synthesis
137
What is the most common side effect of Clarithromycin (macrolide)?
Most common side effects: Nausea, Diarrhea, Distortion of taste
138
What does Bismuth compounds (bismuth subsalicylate - main ingredient in Pepto-Bismol) do for H.pylori treatment?
Disrupt the cell wall of H. pylori
139
What does Bismuth compounds (bismuth subsalicylate - main ingredient in Pepto-Bismol) may do to H.pylori?
May inhibit urease activity and may prevent H. pylori from adhering to the gastric surface
140
What can Bismuth compounds (bismuth subsalicylate - main ingredient in Pepto-Bismol) cause as a harmless effect? **highlighted
Can impart a harmless black coloration to the tongue and stool (melena)
141
What should be included in patient teaching of Bismuth compounds (bismuth subsalicylate - main ingredient in Pepto-Bismol) use? **highlighted
Long-term therapy: Possible risk of neurologic injury
142
What does Tetracycline do to H.pylori?
Inhibitor of bacterial protein synthesis
143
What can happen if tetracycline is used in pregnant/young children?
Use in pregnant patients/young children can stain developing teeth
144
What is wrong with Metronidazole use for H.pylori?
Over 40% of strains are now resistant
145
Most common side effects of Metronidazole use for H.pylori?
Most common side effects are nausea and headache
146
What happens if Metronidazole is used with alcohol
Disulfiram reaction if used with etoh
147
Peptic Ulcer Disease is what?
Open sores on stomach’s protective mucosal lining or upper duodenum
148
How can severe erosion in PUD be complicated?
Severe erosion can be complicated by hemorrhage and perforation
149
How can PUD be?
Can be single, multiple, acute, chronic, superficial, deep
150
What are causes of Peptic Ulcer Disease (PUD)?
Imbalance between protective mucosal < erosive factors
Most common cause - Infection with H. pylori
Second most common cause - NSAIDs
151
What is the most common cause of PUD?
**highlighted slide**
Most common cause - Infection with H. pylori
152
What are risk factors to peptic ulcer disease?
NSAIDs, H. pylori, stress, etoh, steroids, age, smoking
153
What are signs and symptoms of Peptic Ulcer Disease (PUD)
epigastric/abd pain, cramps, heartburn, indigestion, CP, N/V, fatigue, unexplained wgt loss, hematemesis & melena (duodenal ulcers)
154
What are three types of three types of Peptic Ulcers? What is the most common?
Duodenal ulcers (most common)
Gastric ulcers (stomach ulcers)
Stress Ulcers
155
Types of Peptic Ulcers: What are Duodenal ulcers (most common) characterized by?
Characterized by intermittent pain in the epigastric area
156
Types of Peptic Ulcers: When does pain associated with Duodenal ulcers occur?
Pain begins 2-3 hours after eating, when stomach empty
157
Types of Peptic Ulcers: When relieves pain associated with Duodenal ulcers occur?
Relieved by food or antacids
158
Types of Peptic Ulcers: In duodenal ulcers, increased acid load is caused by?
Increased acid load caused from H. pylori
159
What does H.pylori do in Duodenal ulcers?
H. Pylori activates immune cells (T&B lymphocytes), cytokines, neutrophils --> damages mucosa
160
How do Duodenal ulcers heal?
Heal spontaneously but reoccur
161
Types of Peptic Ulcers: Gastric ulcers (stomach ulcers)
What are they?
A lesion in mucosal wall of stomach breaks down mucosal barrier
Permits H+ ions --> mucosa --> Disrupts cell structure
162
Where else can gastric ulcers be seen?
Less freq, more deadly, chronic, can be seen in chronic gastritis
163
What are gastric ulcers seen in chronic gastritis more likely to result in?
more likely to result in obstruction, & increase cancer risk
164
What does histamines do in gastric ulcers?
Histamine released from the damaged mucosa --> vasodilation and increased capillary permeability --> further secretion of acid and pepsin.
165
What can gastric ulcers do to the stomach wall?
Can perforate stomach wall gastric contents enter abdominal cavity
166
What makes pain worse in gastric ulcers?
Pain worse when eating --> anorexia
167
What are stress ulcers?
Major physiological stressor
severe illness or major trauma
168
What can cause stress ulcers?
Due to local tissue ischemia (HF, sepsis, burns, shock, anoxia, sympathetic responses)
169
Complications of all peptic ulcers include?
Complications – **GI hemorrhage (hematemesis or melena)**, obstruction, perforation (destruction of multiple layers), peritonitis, gastric ca
170
Defense factors of the stomach against H.pylori?
Mucus
Bicarbonate
Blood flow
Prostaglandins
171
What is bicarbonate secreted from?
Secreted by epithelial cells of stomach and duodenum
172
What is bicarbonate produced by?
Produced by pancreas, secreted into lumen of duodenum
173
What does bicarbonate do?
Neutralizes acids
174
What happens to blood flow is poor in the stomach?
Poor blood flow --> ischemia, cell injury, and vulnerability to attack by acid/pepsin
175
What do prostaglandins stimulate? What does it promote?
Stimulate the secretion of mucus and bicarbonate, promote vasodilation, maintains submucosal blood flow, suppress gastric acid
176
Patho of PUD: What are aggressive factors leading to PUD?
H Pylori
NSAIDs
Gastric Acid
Pepsin
Smoking
177
What do NSAIDs inhibit?
Inhibit PGs
178
Because NSAIDs inhibit prostaglandins, what does this lead to (having to do with PUD)?
Decrease submucosal blood flow
Suppress mucus/bicarb
Promote gastric acid
Irritant
179
What does gastric acid do in PUD?
Injures cells of GI mucosa, activates pepsin
180
What does pepsin do in PUD?
Proteolytic enzyme in gastric juice
Injures gastric mucosa
181
What does smoking do in PUD?
Delays healing, vasoconstriction
182
Why does Heartburn & acid regurgitation
occur in GERD?
Chyme periodically backs up from the stomach into the esophagus.
Reflux of bile salts, acid and pepsin from the stomach to the esophagus compromises its defenses causing esophagitis, inflammation, ulceration, precancerous lesions (Barrett esophagus)
183
Gastroesophageal reflux disease (GERD)- what is it?
Heartburn & acid regurgitation
184
What would cause GERD?
Abnormalities in LES function, esophageal & delayed gastric motility
185
What does GERD eventually lead to?
Eventually, fibrosis and strictures develop in the esophagus.
186
What occurs in GERD that would lead to dysphagia and weightloss?
Edema, strictures, esophageal spasms, decreased esophageal motility --> dysphagia/wgt loss
187
What has little to no role in GERD?
H. pylori has little to no role
188
Common predisposing factors to GERD?
Hiatal hernia
Delayed gastric emptying
Vomiting
Coughing
Lifting, bending
Constipation
Foods
189
Look at slide 36
gastroparesis
190
What can foods cause that lead to GERD?
Foods like what?
chocolate, peppermint, fatty foods, coffee, and tea decrease lower esophageal sphincter (LES) pressure, predisposing to reflux
191
What do acidic foods do to cause GERD? Like what?
Acidic foods, such as tomato-based products, orange juice, cola, and red wine, may irritate the esophagus.
192
What are common causes of GERD?
There is no single cause for GERD.
Incompetent LES:
lower esophageal sphincter (LES)
193
What does lower esophageal sphincter (LES) do to cause GERD?
An incompetent LES lets gastric contents reflux from the stomach to the esophagus when the patient is supine (lying down on back).
194
What are clinical manifestations of GERD?
Heartburn/Pain/Dyspepsia
Regurgitation
195
What is included in heartburn/pain/dyspepsia?
Burning or tight sensation in the chest --> jaw
196
When does Heartburn/Pain/Dyspepsia
associate with GERD occur?
Usually occurs 60 minutes after eating
Worse at night, rousing from sleep
Sx worse with increased intra-abd pressure
Pain or discomfort centered in the upper abdomen.
197
Regurgitation in GERD
Hot, bitter, or sour liquid coming into the throat or mouth. This sour taste in the mouth occurs after meals.
198
What are treatments for GERD?
Tx: PPIs, H2RAs, antacids, prokinetics
199
Non-Pharm Management for GERD
Smoking cessation
Weight loss
Elevating head of bed
Meal patterns & timing
Avoidance of trigger foods/beverages
200
Non-Pharm Management for GERD
Increased fluid intake with food consumption alone not adequate
Increase consumption of protein-rich diet
Clothing ~ loose
Proper administration of irritating medications ~ remain upright & plenty H2O
Symptom diary
201
How should meals be with GERD?
Avoid 2-3h of bedtime/sleep
Smaller meals
202
What foods/beverages should be avoided with GERD?
Alcohol
Caffeine, chocolate, peppermint
Dietary fat intake
Citrus, oranges, tomatoes, onions & spicy foods, carbonated beverages
203
Classes of Antiulcer Drugs
Antibiotics
Proton Pump Inhibitors
Histamine2 Receptor Antagonists/Blockers
Gastric Lumen Adherent Cytoprotectives
Antisecretory agents that enhance mucosal defenses
Antacids
204
Proton Pump Inhibitors PPIs (What do they end in). What are the prototypes?
"zole"
Prototype: Omeprazole (Prilosec), Pantoprazole (Protonix)
205
What are the most effective drugs for suppression of gastric acid? What do they do?
PPIs
Most effective drugs for suppression of gastric acid, reduce gastric acid by 90%
Fast acting
206
What is the mode of action of Proton Pump Inhibitors? Where do they work?
Works in parietal cells of stomach
207
What is the mode of action of Proton Pump Inhibitors? What do they inhibit?
Irreversible inhibition of H+,K+-ATPase (proton pump)
208
H+,K+-ATPase (proton pump) - what does it do?
This is the enzyme that produces gastric acid
209
How are Proton Pump Inhibitors PPIs metabolized and excreted?
Hepatic metabolism, renal excretion
210
How long is the half life, how long do effects persist of Proton Pump Inhibitors PPIs ?
½ life 1 hr but effects persist long after drug leaves body
211
What do PPIs have to protect against the stomach coating?
Protective EC coated to protect from stomach acid
212
How is Pantoprazole administered?
Pantoprazole – PO, IV push, IV drip for GIB
213
How are Proton Pump Inhibitors PPIs used?
Short-term tx of PUD, erosive esophagitis, GERD
214
How long should Proton Pump Inhibitors PPIs be used?
Limit tx to 4-8wks
215
Proton Pump Inhibitors PPIs work more effectively and faster than what?
More effective & faster than H2RAs
216
What do Proton Pump Inhibitors PPIs prevent?
Prevent stress ulcers
217
Minor adverse effects of Proton Pump Inhibitors PPIs?
Minor: GI ~ n/v/d, CNS ~ headaches, dizziness
218
Major adverse effects of Proton Pump Inhibitors PPIs?
Major: Pneumonia, osteoporosis, acid rebound upon d/c, HypoMg/Ca by reducing intestinal absorption (↑ risk w/diuretics), C.diff
219
What should you teach patients to report immediately with Proton Pump Inhibitors PPIs use?
Teach pts to report diarrhea immediately
220
Nursing Implications of PPIs: How should patient take PPI capsules/tablets?
Capsules & tablets should be swallowed intact, not crushed, split or chewed
221
Nursing Implications of PPIs: When should PPIs be taken?
Depending on PPI may be taken at least an hour to right before meals or just before eating.
Some PPIs taken w/o regard to food
222
Nursing Implications of PPIs: How are the risks v benefits of PPI use?
Risks > Benefits LT use
223
Nursing Implications of PPIs: What should you warn patients about with PPI use?
Inform pts about s/sx of resp infection
224
Nursing Implications of PPIs: What should you encourage patients to maintain while taking PPIs?
Encourage pts to maintain adequate Ca & Vit D intake
225
Nursing Implications of PPIs: How should patients avoid acid rebound?
Advise pts that acid rebound can be minimized by using lowest dose for shortest time.
226
Nursing Implications of PPIs: How should patients manage symptoms?
Sx may need to be managed w/H2RA & antacids
227
Nursing Implications of PPIs: What should you warn patients about?
Inform pts about risk of hypoMg (tremors, muscle cramps, seizures, dysrhythmias)
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Nursing Implications of PPIs: What levels may be increased with PPI use?
Serum levels of Digoxin may be slightly increased
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Histamine2 Receptor Antagonists (H2RAs): What is the prototypes?
Prototype: Cimetidine (Tagamet), Famotidine (Pepcid), Ranitidine (Zantac)
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Histamine2 Receptor Antagonists (H2RAs) MOA: How do histamines act?
Histamine acts through two types of receptors named H1 and H2
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Histamine2 Receptor Antagonists (H2RAs) MOA: When histamine stimulates H2 receptors, what happens?
H2 receptors on parietal cells stimulated by histamine --> promote gastric secretion
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Histamine2 Receptor Antagonists (H2RAs) MOA: When H2RAs block H2 receptors, what happens?
H2RAs block H2 receptors ---> decreased gastric acid secretion & H+ ion concentration
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Histamine2 Receptor Antagonists (H2RAs): Is it selective or nonselective?
Selective blockade of H2 receptors
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What is the pk of Histamine2 Receptor Antagonists (H2RAs)?
PKs: varies by prototype
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How should Histamine2 Receptor Antagonists (H2RAs) be taken? Administration, dose, freq, route?
Administration, dose, frequency, route varies by prototype
May be taken without regard to meals
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What is Histamine2 Receptor Antagonists (H2RAs) used for?
Gastric & duodenal ulcers treatment, **healing, prophylaxis**
GERD
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What does ADR of Histamine2 Receptor Antagonists (H2RAs) depend on?
ADRs (depend on prototype)
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ADRs of Histamine2 Receptor Antagonists (H2RAs) depend on prototype and include?
Pneumonia (elevation of gastric pH)
Stomach candida
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Drug interactions of Histamine2 Receptor Antagonists (H2RAs)
Vary per prototype
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Nursing Implications of H2RAs: How should they be taken?
Most H2RAs may be taken without regard to meals
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Nursing Implications of H2RAs: When is it best to take H2RAs?
Dosing is @QHS for better suppression of nocturnal acid secretion or BID
QHS= once per day at bed time.
BID= twice per day
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Nursing Implications of H2RAs: What should you educate patients about?
Educate pts about s/x GIB
Black tarry stools, coffee-ground emesis
Tx should increase gastric pH > 5 & pain relieved
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Nursing Implications of H2RAs: What should you warn patients about?
Inform pts about s/sx of resp tract infection
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Nursing Implications of H2RAs: How should you take antacids?
Separate from antacids by at least 1 hr
Absorption may be decreased
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Sucralfate [Carafate]- What does it do?
**important**
Creates a protective barrier against acid/pepsin for up to 6 hours
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Sucralfate [Carafate]. Creates a protective barrier against acid/pepsin for up to 6 hours- How?
Forms a viscid sticky gel & adheres to ulcer crater
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Sucralfate [Carafate].- What does it NOT do?
Does not decrease acid secretion/no acid neutralizing capability
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Sucralfate [Carafate].-Therapeutic uses?
Acute ulcers and maintenance therapy
249
PKs of Sucralfate [Carafate].-absorption and excretion?
Adm orally, minimal systemic absorption
90% of each dose eliminated in feces
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Sucralfate [Carafate]- adverse effects?
Constipation (only 2% of patients)
251
Sucralfate [Carafate]- how can it be taken?
Tx 4-8 wks
Can be halved, broken, or dissolved in 15-30mL H2O to form a slurry
Tablets do not crush well, but you may try splitting tablets.
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Sucralfate [Carafate]- Drug interactions
How should antacids be administered with this med? Why?
Antacids may interfere with effects of sucralfate by raising gastric pH >4
Adm 30 min apart
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Sucralfate [Carafate]- Drug interactions
may impede absorption of some drugs- what does that mean?
May impede absorption of some drugs, so adm 2h apart
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Misoprostol (Cytotec): MOA- what is this med a replacement for?
MOA: Replacement for endogenous prostaglandins
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Misoprostol (Cytotec): Uses of med
Uses: prevention of gastric ulcers caused by LT NSAID tx
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Misoprostol (Cytotec): ADRs?
diarrhea, abdominal pain
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Misoprostol (Cytotec): Contraindicated in?
Contraindicated in pregnancy
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Misoprostol (Cytotec): Why is it Contraindicated in pregnancy?
PGs stimulate uterine contractions
Can cause partial/complete expulsion of developing fetus
Women if childbearing age must comply with birth control, be advised on dangers, & have neg pregnancy test within 2 weeks before beginning tx
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Misoprostol (Cytotec): What must women of child bearing age have before starting med?
Women if childbearing age must comply with birth control, be advised on dangers, & have neg pregnancy test within 2 weeks before beginning tx
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COmbinations of Antacids available?
(Start with aluminum hydroxide)
Aluminum hydroxide + magnesium hydroxide + simethicone (Mylanta)
Aluminum hydroxide + magnesium hydroxide (Maalox)
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Combinations of Antacids available?
(Last 2 not including Aluminum hydroxide)
Calcium Carbonate (Tums)
Sodium bicarbonate (Alka-Seltzer)
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What are antacids used for?
Used for hyperacidity, indigestion, reflux
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Antacids are available in suspensions and tablets, how should they be taken in these forms?
Suspensions - shake well
Chew tablets thoroughly, then H2O or milk
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What kind of tablets are Antacids?
Effervescent tablets
Effervescent tablets are designed to release carbon dioxide upon contact with water, promoting their disintegration.
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How should antacids be taken?
Taken regularly, not PRN
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How should dosing of antacids be? Why?
Short duration of action = frequent dosing
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What kind of compounds are antacids? What does this mean they do?
Alkaline compounds that neutralize stomach acid
Reduce destruction of gut wall
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What are antacids used for?
Uses: PUD, sx of GERD (no studies demonstrate efficacy)
Can provide prophylaxis against stress-induced ulcers & symptomatic relief, but they do not accelerate healing.
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How do antacids effect stomach pH?
Except for sodium bicarbonate, antacids do not alter systemic pH
270
What has antacid use been replaced by?
H2RAs & PPIs
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Who should use antacids cautiously?
Use with caution in patients with renal impairment
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Adverse effects of antacids?
Constipation: Aluminum hydroxide
Diarrhea: Magnesium hydroxide
Combinations can minimize bowel effects (Maalox)
Sodium loading
-Caution with HF
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What are adverse effects of antacids with Aluminum hydroxide
Constipation
274
What are adverse effects of antacids with Mg hydroxide
Diarrhea
275
Drug interactions (due to increased pH)
in antacids would occur why?
(due to increased pH)
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Drug interactions (due to increased pH)
Antacids:
Elevation of urinary ph can excrete acidic drugs & delay excretion of basic drugs
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The ADRs of antacids for drugs interactions means what?
Allow at least 1 between antacids and other meds (eg ASA)
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Antacids: Magnesium Hydroxide [Milk of Magnesia]- what is the most prominent adverse effect?
Most prominent adverse effect is diarrhea
279
What is Magnesium Hydroxide usually taken with?
aluminum hydroxide
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Who should Magnesium Hydroxide [Milk of Magnesia] be avoided in?
Who should it be used cautiously in?
Avoided in patients with undiagnosed abdominal pain
Stimulation of bowel could be dangerous
Use with caution in patients with renal failure- Mg can accumulate to toxic levels (eg CNS depression)
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Aluminum Hydroxide- what does it do?
Binds to pepsin, which may facilitate healing
282
Antacids: What does Aluminum Hydroxide bind with?
Binds with phosphate
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When Aluminum Hydroxide binds with phosphate, what does it cause?
Reduce absorption & cause hypophosphatemia
284
What does Aluminum Hydroxide drug interactions include? What would binding effects be?
Tetracyclines, warfarin, digoxin
Binding may reduce their effects
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Calcium Carbonate (Tums)- What do they act as? How long is their duration of action
Also acts as calcium-based phosphate binder
Long duration of action
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Principle adverse effects of calcium carbonate (Tums)
Principal adverse effect: Constipation, which can be overcome by combining calcium carbonate with a magnesium-containing antacid (eg, magnesium hydroxide)
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Rare side effect of calcium carbonate?
Milk-alkali syndrome
288
Milk-alkali syndrome
Condition characterized by hyperCa++, met alk, soft tissue calcification, impaired renal function
Taking too many calcium supplements or chronic ingestion
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Who should calcium carbonate be used cautiously in?
Caution with renal patients (e.g calcium & phosphate levels)
