CH 59+ 60, GI Flashcards
(44 cards)
Physiology of Upper Gastrointestinal Tract
- stomach secretes acid, enzymes, and hormones that are essential to digestive physiology
What are the natural defenses of the stomach?
- somatostatin
- bicarbonate ion
- mucus
- prostaglandin E2
What do prostaglandin antagonists include?
- NSAIDs/ASA (damages GI mucosa directly)
- corticosteroids
Peptic ulcer risk factors
- infection w/ H. pylori
- close family hx of PUD
- drugs
- blood group O
- smoking tobacco
- excessive caffeine
- psychological stress (thought to be primary cause of PUD)
what drugs increase risk of peptic ulcer disease (PUD?)
- glucorticoids
- NSAIDs
- platelet inhibitors
PUD: NSAID-induced risk factors
- long-term use
- advanced age
- hx of ulcers
- corticosteroids
- anticoagulants
- alcohol + smoking
Goals of PUD pharmacotherapy
- relieve symptoms
- promote healing
- prevent complications
- prevent future recurrence
what do PPIs end in? and what do they do?
“-prazole”
- PPIs block gastric acid secretion
- choice of drug therapy in PUD + gastroesophageal reflex disease
H2 -receptor antagonists - what do they do?
suppress gastric acid secretion & are widely prescribed for treating PUD + gastroesophageal disease
what are the H2-receptor antagonists?
- ranitidine (Zantac)
- cimetidine (Tagamet)
- famotidine (pepcid)
- nizatidine (axid)
H2 receptor antagonists - Pharmacokinetic properties
- rapid absorption from SI
- 30 minute onset of action
- half-life from 1-4h
- no known effects on fetus
- excreted primarily from kidneys
what are antacids?
= alkaline substancse that neutralize stomach acid to treat symptoms of heartburn
Antacids Pharmacotherapy: AEs
- constipation
- @ high doses, aluminum products bind w/ phosphate in GI tract = LT use can result in phosphate depletion
- high risk in: malnourished, alcoholics, renal disease
Symptoms of bowel obstruction
abdominal distension, n/v, bloating, tender
SNT - soft, non-tender, no distention?
Antacids: Contraindications / precautions
- prolonged use with low serum phosphate
- avoid w/ suspected bowel obstruction
Antacids: Drug Interactions
- don’t take with other meds – will interfere w/ absorption
- anticholinergic drugs incr effects of antacids
- aluminum + calcium antacids may inhbit absorption of dietary iron
- decr absorption of some drugs
Antacids decrease the absorption of which drugs?
- cimetidine
- fluoroquinolones
- digoxin
- isoniazid
- chloroquine
- NSAIDs
- iron salts
- phenytoin
- tetracycline
- thyroxine
Considerations w/ Antacids
- PMH
- watch kidney labratory values
- monitor for bowel changes & worsening symptoms
- **hold drug + notify prescriber **if pt has symptoms of appendicitis, undiagnosed GI bleeding, or suspected obstruction
What helps with simple nausea, such as motion sickness?
Pharmacotherapy of N/V
- anticholinergic agents (scopolamine)
- antihistamines (dimenhydrinate/diphenhydramine)
What helps with chemotherapy-induced N/V?
Pharmacotherapy of N/V
- serotonin (5-HT3) receptor antagonists (Zofran)
what is the primary indication for the use of antiemetic medication?
chemotherapy-induced nausea and vomiting
what is used for antineoplastic therapy?
Pharmacotherapy of N/V
- phenothiazine (methotrimeprazine / Nozinan)
- hydroxyzine (Atarax)
- dopamine antagonists –> Metoclopramide (Reglan)
Ondansetron - Therapeutic + Pharmacological classification?
therapeutic: antiemetic
pharmacologic: serotonin (5-HT3) receptor antagonist
