Pharm: Secretion Disorders Flashcards
1
Q
Dyspepsia
A
- Upset stomach
- alleviated by reducing gastric acid
- GERD
- Peptic Ulcer Disease
- gastric and duodenal
- stress-induced
2
Q
Antacids
A
- Neutralize gastric acid
- inhibit pepsin activity
- Acid+weak base=Salt + H2O
3
Q
Examples of Antacids
A
- Sodium Bicarbonate
- Baking Soda
- Produces :NaCl, H2O, Co2=Belching
- Bicarbonate is absorbed
- alkinalization-increased excrtion of weak acids
- Calcium Carbonate
- TUMs
- carbonate is absorbed
- contains calcium:
- wantedl-osteoporosis
- unwanted
- increased MI risk
- Kidney stones
- Hypercalcemia with excessie use
- Aluminium Hydroxide
- No CO2-No belching
- Constipation
- Magnesium Hydroxide
- No CO2-No belching
- Diarrhea
- Combined: Magnesium/Aluminum hydroxide
- no gas and belching
- FEWER absorption problems with hydroxide=less alkalinzation
4
Q
Antacids: Concerns
A
- No safety concerrns
- but ALTERED absorption and excretion of otehr drugs
- slowed disoolution of tablets and capsules
- adsorption and chelation may slow absortiopn
- alkalinzation of urine increases acid excretion
- Recommend: seperate doses of antacids and other drugs by 2 hours
- w/impaired renal function
- decreased excretion of absorbed metals
- Patients consider them not a drug
5
Q
H2 Antagonists
A
- Reversible
- “tidine” family
- Cime
- rani
- Ramo
- Niza
- effective against pepsin and acid production
- effective against nightime GERD
6
Q
H2 antagonists: Pharmokinectics:
A
- Rapid intestinal absoprtion
- First pass metabolism; Except Niazatidine
- 50% bioavailability
- Liver metabolism and urinary excretion are important for elimination
- except nizatidine excretion=urinary
- Renal trouble=reduce doses
7
Q
Ranitidine
A
- aka Zantac
- H2 antagonist
- removed from market due to NDMA carcinogen
- Drug itself is fine
8
Q
Cimetidine
A
- H2 antagonist
- Potent cytochrome P450 inhibitor
- CYP1A2
- CYP2D6
- CYP3A4
- May increase blood levels of
- warfarin
- phenytoin
- theophylline
- calclium channel blockers
- diltizem
- felodipine
- nifedipine
9
Q
PPIs
A
- Prazole family
- ome
- esome
- panto
- lanso
- rabe
- All are prodrugs
- administered orally in enteric coated capsules
- food reduces absorption-take before meal
- Dissolution occurs in the intestine
- compounds are lipophilic weak bases
- diffuse into parietal cells and portonate=trapped to have efffect
- Takes a day for effects
- Short half life, but irreversible inhibition leads to persistent effects
10
Q
PPI Effectiveness
A
- Daily dose is usually curative
- peptic ulcer typically QD
- once daily
- GERD typically BID
- twice a day
- peptic ulcer typically QD
- H. pylori can cause relapse
- most cases of peptic ulcer
- usually given with antibiotic
- clarithromycin
- metronidazole
- amoxicillin
11
Q
PPI Problems
A
- Reduce absorption of:
- vitamin b12
- Mg2+
- Changes in normal flora-increase in enteric infection
- Increased Gastrin Signaling
- elevated pH–>Positive feedback–>increase number of ECL cells
- Concern about promoting cancer
- Reduces Clopidogrel efficacy
- inhibit CYP2C19
- esomeprzaol and omeprazole reduce 50%
- pantaprazole may also casue
12
Q
PPIs: problem in elderly
A
- Increased risk of:
- c. difficile infection
- bone fracture
- due to reduced Mg2+ absorption
- community-acquired pneumonia
- mortality in finnish nursing homes
- CORRELATION IS NOT CAUSATION
13
Q
Agents for Mucosal Protection
A
14
Q
Sucralfate
A
- forms a paste
- creates a physical barrier to acid and digestive enzymes
- sticks to gastric lesions
- Stimulates other protective responses
- prostaglandin release
- bicarbonate secretion
- Safe and effect
- little is absorbed
- constipation may occur
