Anti-ulcer drugs Flashcards
1
Q
role of gastric acid
A
- digestion of proteins
- activates proenzymes
- absorption of calcium, iron, B12
- suppresses bacterial growth
2
Q
stimulation of parietal cells
A
- ACh
- gastrin
- histamine
3
Q
Ach function
A
- major neural stimulatory of parietal cells
- increases gastrin release
- inhibits somatostatin
4
Q
gastrin function
A
- major endocrine regulator
- release triggered by a protein meal and gastric distention
- increases histamine release
5
Q
histamine function
A
- major autocrine/paracrine stimulator
6
Q
inhibitors of parietal cells
A
- somatostatin and prostaglandins
7
Q
somatostatin function
A
- inhibitor of acid secretion by inhibiting gastrin and histamine release
8
Q
prostaglandin function
A
- inhibit acid secretion by decreasing cAMP
- stimulation secretion of mucin and bicarbonate
- inhibited by NSAIDs
9
Q
PPI MOA
A
- irreversibly block active H/K ATPase pumps in parietal cells
- if the pumps are inactive the drug will not work
10
Q
PPI pharmacokinetics
A
- highly protein bound
- metabolized in the liver by P450, specifically CYP2C19 and CYP3A4
- should be taken 20-30 minutes before breakfast
11
Q
PPI adverse effects
A
- diarrhea
- increased gastrin level: hyperplasia of ECL cells, rebound hypersecretion of acid once PPI discontinued
- risk factor for C. difficile colitis
- risk factor for hip fracture and hypomagnesmia
12
Q
PPI drug interactions
A
- PPIs may inhibit CYP2C19 which decreases clopidogrels antiplatelet effect
- dexlansoprazole is only PPI FDA approved for concominant use with clopidogrel
- most are pregnancy B except omeprazole which is class C
13
Q
common H2RB
A
- ranitidine (Zantac)
- famotidine (Pepcid)
14
Q
HR2B MOA
A
- inhibit acid production by reversibly competing with histamine for binding to H2 receptors
- give at night
15
Q
H2RB pharmacokinetics
A
- absorbed rapidly, peak concentration in 1-2 hours
- small % protein bound
16
Q
H2RB drug interactions
A
- mainly with cimetidine
- cimetidine inhibits cytochrome P450 more so than do other agents of this class
- pregnancy class B
17
Q
prostaglandin analogue MOA
A
- stimulates secretion of mucin and bicarbonate
- acid suppression at cellular interface is most critical effect
18
Q
prostaglandin side effects
A
- diarrhea
- abortion risk
19
Q
antacid MOA
A
- neutralized the acid environment
20
Q
antacid side effects
A
- careful in chronic renal disease
- hypermagnesemia: N/V, weakness, hypocalemia, arrhythmias
- milk- alkali syndrome: hypercalemia, alkalosis, renal impairment
21
Q
bismuth subsalicylate indications
A
- used to treat diarrhea, heartburn, and upset stomach
- used in combo with other meds (PPIs, antibiotics) to treat H. pylori induced ulcers
22
Q
bismuth side effects
A
- black stools, people may think upper GI bleed
23
Q
GERD severity stage I
A
- sporadic uncomplicated heartburn
- 2-3 episodes per week
- treat with lifestyle modification and antacid or H2RB as needed
24
Q
GERD severity stage 2
A
- more frequent symptoms
- greater than 2-3 episodes per week
- PPI more effective than H2RB
25
GERD severity stage 3
- chronic unrelenting symptoms
- relapse off treatment
- EGD shows complications: Barrett's, stricture, ulcers
- PPI once or twice daily: 30 minutes before breakfast and 30 before dinner
- PPI and H2RB: PPI 30 minutes before breakfast, H2RB at bedtime
26
PUD treatment
- mainstay of treatment are PPIs
- if H pylori present then:
- PPI twice daily for 7-14 days AND
- amoxicillin for 7-14 days AND
- clarithromycin for 7-14 days
- if allergic to penicillins then give metronidazole
27
risk factors for acute GI bleeds secondary to PUD
- mechanical ventilation more than 48 hours
| - coagulopathy
28
active ulcer or bleeding
- low bp
- high HR
- low hemoglobin/ hematocrit
- increased BUN/Cr ratio
29
treatment for active bleeding
- endoscopic therapy is mainstay
| - plus pantoprazole (protonix)
30
curling ulcer
- associated with severe burns and volume depletion leading to ischemia and cell necrosis diminishing the mucosal barrier
31
cushing ulcer
- associated with increased intracranial pressure, and theorized to increase ACh stimulation of parietal cells
32
risk factors for developing stress ulcers
- mechanical ventilation for more than 48 8hours and coagulopathy
33
treatment of ZES
- PPIs twice daily
