Medication for GI Flashcards
Histamine 2
PUD
treatment of H.pylori
Drug:
* Histamine 2- receptor antagonists
* Cimetidine (H1 and H2)
* Ranitidine (H2)
* Famotidine
Therapeutic use
* treats gastric and duodenal ulcers
* GERD
* Zollinger Ellison syndrome, hypersecretion of gastric acid and development of acid and development of peptic ulcers
* Heartburn acid indigestion and sour stomach
MOA
* promotes ulcer healing by suppressing secretions of gastric acid
* prevents erosion of the gut wall
* Activation of H1 receptors produce symptoms of allergies
* Activation of H2 receptors are located on peripheral cells of the stomach and promote secretion of gastric actid
Side effects
Cimetidine:
* Antiandrogenic effect- binds two androgen receptors causing gynecomastia, reduced libido, and impotence
- CNS effects- most likely in older adults who have renal or hepatic impairment
- Confusion, hallucinations, CNS depression (lethargy, somnolence), and CNS excitation (restlessness, seizures)
- Pneumonia- related to gastric pH elevation and decreasing healthy upper GI flora
Ranitidine & Famotidine:
* CNS effects are rare due to penetrating the BBB poorly
- Does not cause anti androgenic effects
- Pneumonia- related to gastric pH elevation
Drug interactions:
Cimetidine:
* Increases blood levels of Coumadin, Dilantin and theophylline
* Ranitidine & Famotidin
Pt. teaching
Cimetidine:
* Do not give cimetidine to the elderly due to CNS effects
Ranitidine:
* Immediate removal from shelves in 2020 due to cancer causing contaminants can build up over time
All:
* Educate and monitor for s/s of pneumonia or URI
Nurse education for PUD:
- Small frequent meals for peptic ulcers
- Stop smoking to prevent vasoconstriction
- Decrease or stop NSAIDs
Proton pump inhibitors
Drugs
* Esomeprazole
* Lansoprazole
* Omeprazole
Therapeutic use
* GERD
* Gastric and duodenal ulcers
MOA
* blocks all acid production
* inhibits gastric acid pump of the parietal cells
Adverse effects
* HA,N,V,D
* Fractures (reduces acid secretion and decreases absorption of calcium)
- Pneumonia (alter upper GI flora/reduces gastric acidity, impairment of WBC function)
- Acid rebound (hypersecretion of gastric acid)
- Intestinal infection with C. diff (diarrhea/abdominal pain)
- Hypomagnesium (reduce intestinal magnesium absorption)
- Gastric cancer (hypersecretion of gastrin)
Drug interaction
* Clopidogrel (decrease adverse effects and reduce beneficial effects)
- Decrease absorption of HIV/AIDS medications
pt. education
* Most effective inhibitor of gastric secretions
* Short half-life
* More expensive
* Used for short term therapy and lowest dose possible
* Report serious adverse event symptoms ASAP
antacids
Drugs
* Aluminum hydroxide
* calcium carbonate
* magnesium hydroxide
Therapeutic use
* Heartburn
* GERD
* PUD
MOA
- Neutralizes gastric acid by buffering hydrochloric acid
- making hydrochloric acid less corrosive
Adverse effects
* Constipation (aluminum and calcium)
- Diarrhea (magnesium)
- Toxic levels of calcium and magnesium can accumulate in patients with renal failure (due to difficulty excreting medication from body)
- May cause sodium loading due to large amounts of sodium in the antacid
- Can exacerbate hypertension and heart failure
Drug interactions:
* Can influence the dissolution and absorption a H2RAs due to raising gastric pH
- Can disrupt the absorption of iron and antibiotics
pt. education
* Use cautiously in renal failure due to difficulty excreting medication from body (calcium, magnesium)
- Administer drug at least 1-2 hours from sucralfate, H2RAs, antibiotics and Iron
- Do not use antacids for more than two weeks
- Use cautiously in patients with hypertension, CHF, and renal insufficiency
sucralfate
Therapeutic use
* acute therapy and maintenace therapy of duodenal ulcers
* PUD
MOA
* ANTI-ulcer med
* promotes ulcer healing by creating a barrier against acid pepsin
* has no acid neturalizing capacity and does not decrease acid secretion
* not systemically absorbed
Adverse effects
* limited
* constipatation and nasuea most common
Drug interaction
* antacids may interfere with sucralfate effects
* may decrease the absorption of Phenytoin, theophylline, digoxin, warfarin, and fluroroquinolone antibiotics
pt education
* administer antacids and sucralfate atleast 1-2 hours a part
* Administer other medications and sucralfate at least 2 hours apart
* Administer 30 minutes to one hour prior to meals
Misoprostol
Therapeutic use
* prevents gastric ulcers caused by long term therapy with insets
* used to promote cervical ripening and in combination with mifepristone to induce medical termination of pregnancy
MOA
* Prostaglandin E1 analog: replacement for endogenous prostaglandis)
* prostaglandis helps protect the stomach by suppressing secretion of gastric acid, which promotes the secretion of bicarbonate and cytoprotective mucus
* asprin and other incidents cause gastric ulcers by inhibiting prostaglandin biosynthesis
Adverse effects
* Diarrhea, and abdominal pain
* spotting and dysmenorrehea in women
contraindicated in pregnant women
Bulk forming laxatives
drugs
* Psyllium
Therapeutic use
* constipation
* therapeutic group 3
MOA
* contains natural or semisynthetic polysaccarides and cellulose derived from grains and other plant material
* fxn like fiber
* causes water to be retained in stool
* agents are non-digestable and non-absorbable
Adverse effects
* Esophageal obstruction
* gas formation
* intestinal obstruction
* may be contraindicted in pt. who may have GI obstruction or impaction
pt. education
* glass of water to prevent esophageal obstruction
- Should produce a soft formed stool in 24-72 hours
- Do not use in patients who may have GI obstructions or impaction & monitor for S/S of intestinal obstruction when given to patients
laxitive education
- Increase fluids and fiber
- Dietary fiber is always best before chemical use
- Have a bowel movement when the need is felt (defecation reflex)
- Exercise after meals
- Laxative overuse can lead to electrolyte imbalance
- Do not use in patients who may have GI obstructions or impaction & monitor for S/S of intestinal obstruction when given to patients
Surfactant laxatives
Drug
* Docusate sodium
Theapeutic use
* constipation
* Therapeutic group 3
MOA
* Lower surface tension which faciliates the penetration of water into the feces
* acts onto the intestinal wall to inhibit fluid absorption and stimulate secretion of water and elctrolyes into the intestinal lumen
** Adverse effects**
* abdominal cramping
pt education
* should produce a soft stool with 1-3 days
* best for cardiac patients
stimulate laxatives
Drug
* Bisacodyl
* rectal suppository & PO enteric tablet
* Senna
Therapeutic use
* constipation
* treatment of opiod induced constipation
* Therapeutic group II
MOA
* Stimulates intestinal motility (nerve stimulation)
* increases the amount of water and electrolytes within the intestinal lumen by increasing secretion of water into the intestine
* Reduced water and electrolyte absorption
Adverse Effects
* systemic absorption followed by renal secretion may cause a harmless yellowish brown or pink color in the urine
Drug/ food interaction
* do not administer with milk and antacids
* accelerates dissolutions of the enteric coating
pt. education
* PO acts within 6-12 hours
* suppositorys act rapidly within 15-60 min
* produce a soft or semi fluid stool
* swallow pills intact due to enteric coating
– prevents gastric irritation
* seperate milk and antacids within 1-3 hours of ingestion
* urine discoloration is a harmless side effect
osmotic laxitives
Drug
* Magnesium hydroxide
* sodium phosphate
* magnesium citrate
Therapeutic use
* constipation
* bowel prep
MOA
* Draws water into the intestinal lumen
* peristalsis is stimulated by the swelling of the fecal mass due to the acculumation of water
Adverse effects
* can cause substantial loss of water which leads to electolytes imbalance
* magnesium can accumulate to toxic levels in those with renal issues
* sodium absorption can cause fluid retention
* sodium phosphate can cause acute renal failure in high-risk patients
* kidney disease
* ACE, ARBs, diruetics
pt education
* produce a soft or semi fluid stool within 6-12 hours of absorption
* rapid acting within 2-6 hours cause fluid evacuation in high doses
* high dose therapy is used for procedures
* pt. should increase fluid intake to avoid dehydration
* magnesium salts are contradicted in pt with kidney disease
* sodium phsophate should be avoided din high-risk pt
* MOM in the Am for a bowel mvmt in the Pm
Lubricants
Drugs
* Glycerin suppository
* mineral oil
Therapeutic use
* constipation
MOA
* lubricates intestinal wall and softens stool
Adverse effects
* affects absorption of fat soluble vitamins
produces stool within 12-18 hours
Loperamide
Therapeutic use
* Dirrhea
* reduce the volume of discharge from ileostomies
MOA
* a strucutal analogue of meperidine
* suppresses bowel motility
* suppresses fluid secretion into the intestinal lumen
Adverse effects
* constipation
benefits over diphenoxylate
* blood is poorly absorbed and is not readily crossed the blood brain barrier
* very large oral doses do not elicit morphone like subjective effects
* Loperamine has little or no potential for abuse and is not regulated unter teh controlled substance act
Diphenoxylate with Atropine
Therapeutic use
* opioid used only for diarrhea
* in combination with atropine to discourage diphenoxylate abuse
MOA
* Acts through the autonomic nervous system on the nerve endings in the intenstinal wall
* reduces peristalis and GI motility
* Atropine–> anticholinergic agent
* decreases peristalis and muscular tone of the intestines
Adverse effects
* Constipation
* decreased respiratory effort if takin in high doses
Benefits
* drug is insoluable in water and cannot be abused by parental routes
* PO in antidiarrheal doses has no effect on the central neverous system
- hold if patient is having symtoms of constipation
Ondansetron
Therapeutic use
* chemo related N/V/
* morning sickness of pregnancy
MOA
* serotonin receptor antagonist
* blocks type 3 serotonin receptors located in the CTZ and on the afferent vagal neutons in the upper GI tract
Adverse effects
* HA, diarrhea, constipation, dizziness and sedation
* prolongs the QT interval and poses a risk of torsades de point dysthythmia
Contraindications
* pt with electrolyte abnormalites
* heart failure
* brady dyrhythmias
* long QT syndrome
* those taking other QT drugs
Benefits
* does not block dopamine receptors
* does not cause the extrapyramidals effect scene with anti-emetic phenothiazines
pt. nurse
* education on most common side effect
* not to be used for long term use
Dexamethasome
Therapeutic uses
* Chemo related N/V/
* Used in combination with other antiemetics IV
MOA
* suppression on emesis is unknown
Adverse effects
* uses intermittent in short term therefore serious side effects are absent
