Pharm 2 Exam #3 (Chpt. 42, 13, 12, 14) Flashcards
Compare the pharmacologic treatment of vomiting, diarrhea, and constipation
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Chapter 42, objective #1
Vomiting: vestibular system and chemoreceptor trigger zone are very close to one another causing N/V sensory input; S/Sx: salivate, dry heaving
Diarrhea:
Constipation:
RN Implications for taking drugs for the GI tract
Obtain diet, travel, illness and medication history
Monitor vitals
Monitor hydration (vomiting and diarrhea can lead to severe dehydration and shock)
Monitor bowel sounds – hypoactivity or hyperactivity
Provide oral hygiene
Provide pericare
Monitor for side effects of medications
Encourage nonpharmagological therapies as first line treatment
Drugs to treat GI problems
— Antiemetics
— Emetics
— Antidiarrheals
— Laxatives
Location of chemoreceptor trigger zone (CTZ) + vomiting center
CTZ: lies near the medulla
Vomiting center: inside the medulla
What are things to trigger the CTZ?
— Drugs
— Toxins
— Vestibular center is in the middle ear
Which stimulates the vomiting center?
What are the direct triggers of the vomiting center?
Think sensory impulses
— Odors
— Smells,
— Taste
— Gastric mucosal irritation
Neurotransmitter actions of CTZ and vomiting center
— Dopamine stimulates the CTZ
— Acetylcholine stimulates the vomiting center
Non-pharmacological measures for vomiting
1st step to treatment of GI problems
Weak tea
Flat soda
Gelatin
Pedialyte (for use in children)
Gatorade
Crackers
Dry Toast
Peppermint/ginger
Mild nausea may be relieved by applying acupressure on the inside of your wrist
BRAT diet when Tx of GI d/o’s: bananas, rice, applesauce, toast
Nonprescription Antiemetics
2nd step to Tx of GI problems
Antihistamines:
Dimenhydrinate (Dramamine) —
— provides anticholinergic effects = drowsiness, dry mouth, constipation so increase fluid and fiber intake, take 30-60minutes before activity
Bismuth subsalicylate (Pepto-Bismol)
may have allergic rxn b/c has trace amounts of sulfa/aspirin
NOTE: RISK OF REYE’S SYNDROME FOR CHILDREN WITH VIRAL SYNDROMES WHEN TAKING PEPTO-BISMOL!!
Prescriptive Antiemetics: Antihistamines
3rd option to tx to imitigate nausea/GI problems
_Action: act primarily on the vomiting center | decrease stimulation of CTZ + vestibular pathways
NOTE: Antihistamines have CNS depressive effects so sedation and respiratory depression is a concern, especially if combined with OTHER CNS depressants = problem if drug is used to counteract the emetogenic properties of opiates!
Prescriptive Antiemetics Examples: Antihistamines + Anticholinergics
3rd option to Tx GI problems
Hydroxyzine (Vistaril)
Promethazine (Phenergan)
Scopolamine (Transderm-Scop)
Side effects for Antiemetics: Antihistamines + Anticholinergics
Side effects: drowsiness, dry mouth, blurred vision caused by pupillary dilation, tachycardia (with anticholinergic use), and constipation
— These drugs should not be used by patients with glaucoma
Differences b/w: emesis, emetogenic, antiemetic
Emesis = vomiting
Emetogenic = something that causes nausea/vomiting; e.g. chemotherapy drugs
Antiemetics = medicines that imitigate nausea
How long should OTC antihistamines for motion sickness be taken before travel?
30 minutes before travel
NOTE: antihistamines inhibit vestibular stimulation in the middle ear
Antiemetics Drugs
— Dopamine antagonists
Phenothiazine antiemetics: Chlorpromazine (Thorazine) | Prochlorperazine edisylate (Compazine) | Promethazine (Phenergan) |
— Droperidol (Inapsine): Butyrophenone (NOT for patients w/ QT prolongation) |
Diphenidol (Vontrol), trimethovbenzamide (Tigan)
Miscellaneous Antiemetics
Action:
— suppress impulses to CTZ and reduce sensation of nausea
Side Effects:
— drowsiness + anticholinergic Sx b/c meds reduce availability of dopamine, which will relieve of N/V, but may cause EPS effects (Parkinson’s)
— Trimethobenzamide can cause HoTN, diarrhea, and EPS
Causes of Diarrhea
Spoiled foods or excessively spicy foods
Bacteria (Escherichia coli, Salmonella), virus (parvovirus, rotavirus), toxins
Drug reactions
Fecal impaction, laxative abuse
Malabsorption disorders, bowel tumor, inflammatory bowel disease
Stress, anxiety
Non-pharmacological measures for treating diarrhea
— Clear liquids
— Oral solutions (Gatorade, Pedialyte, Rehydralyte [both if use in children])
— IV electrolyte solutions
— Grab a small cup (~30mL/cc) and pour liquid (H2O, flat soda, Pedialyte, etc) and have person sip on it every few minutes; if capable of drinking 2 “cups” per hour = 1/2 cup drunken within the 1 hour
Purpose, caution, and types of Antidiarrheals
Purpose: decrease hypermotility in the gut
Caution: should nOT be used for more than 2 days or if fever present
Types:
— Opiates and opiate-related agents
— Somatostatin analogue
— Adsorbents
— MIschellaneous
Diarrhea = constipation = opstimation (chronic constipation) = colon rupture/perforation (trying to get rid of stool) = sepsis = death
Metoclopramide (Reglan)
Mischellaneous Antiemetics
Action: suppress impulses to CTZ and increases GI transit time
Side effects: high doses can cause sedation and diarrhea; occurrence of EPS is more prevalent in children than adults (tardive dyskinesia) |
Contraindicated w/: GI obstruction, hemorrhage, or perforation
Ipecac (OTC)
Emetic
Action: stimulates CTZ and acts directly on gastric mucosa
Use: induces vomiting after toxic substance
Caution:
— avoid vomiting if substance is caustic or petroleum
— if vomiting contraindicated, activated charcoal or gastric la age can be used
Substances that induce emetics + use of Ipecac
Caustic substances: ammonia, chlorine bleach, lye, toilet cleaners, battery acid
Petroleum substances: gasoline, kerosene, paint thinners, lighter fluid
Activated charcoal is used when emesis is contraindicated.
RN Interventions:
— Ipecac is considered appropriate in isolated cases for the patient who is alert and if administered within 1 hour of poisoning
— Be sure to use ipecac syrup and not ipecac fluid extract
— Give with glass of water…not milk or sodas Vomiting usually begins within 15 to 30 minutes of ingestion
Diarrhea can lead to
— Malabsortion disorders (UC, Crohn’s, Celiac Disease)
— Bowel tumor
— Inflammatoy bowel disease
Antidiarrheals: Opiates, Opiate-related agents
Diphenoxylate with atropine (Lomotil) — contraindicated with IBD b/c can cause severe complications of toxic mega colon
Difenoxin (Motofen)
Loperamide (Imodium)
Opiates decrease GI motility.
Opiates may cause respiratory depression.
Especially children and older adults
May cause physical dependence
Atropine contraindicated in glaucoma.
What is the key differences between Imodium vs. Lomotil
Imodium is structurally related to Lomotil but causes less CNS depression and can be purchased as an OTC drug.
NOTE: Prolonged use of these meds may cause physical dependence.
What Antidiarrheals do you NOT use to treat Traveler’s Diarrhea? Why?
**Ioperamide (Imodium) **
— Is used cautiously as it slows peristalsis and may also slow the exit of infectious organism from the GI tract (causing infectious diarrhea).
— Allow patient to poop it out as opposed to slowing and maintaining bacteria in the gut if using this drug
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NOTE: Traveler’s diarrhea can be reduced by drinking bottled water, washing fruit, and eating cooked vegetables. Meats should be cooked until well done.
Pharmacological options for nausea
Prescriptive antiemetics
Antihistamines
Anticholinergics
Dopamine antagonists
Benzodiazepines
Serotonin antagonists
Glucocorticoids
Cannabinoids (for patients with cancer)
Miscellaneous
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NOTE: these drugs act as antagonists to dopamine, histamine, serotonin, and acetylcholine, which are all associated with N/V
— Cannabinoids: dronabinol (Marinol)
— Miscellaneous: Diphenidol (Vontrol), Trimeth (reduce availability in Dopamine that can trigger EPS), Metoclopramide (Reglan),
Antihistamines + Anticholinergics to combat N/V
Hydroxyzine (Vistaril)
Promethazine (Phenergan)
Scopolamine (Transderm-Scop)
Side effects: drowsiness, dry mouth, blurred vision caused by pupillary dilation, tachycardia (with anticholinergic use), and constipation
These drugs should not be used by patients with glaucoma.
Why can you not give patients Antihistamines and Opiates together?
** — Antihistamines + Opiates = additive effects r/t respiratory depression**
— Antihistamines and anticholinergic agents reduce opioid-induced vestibular sensitivity.
— Antihistamines have CNS depressant effects and adding an opiate will have sedating effect adding to respiratory depression
Dopamine antagonists that combat N/V
Phenothiazine antiemetics
Chlorpromazine (Thorazine) — used as an antipsychotic
Prochlorperazine edisylate (Compazine)
Promethazine (Phenergan)
droperidol (Inapsine)
Butyrophenone — (Haldol found in this category for antipsychotic patients)
Contraindicated in patients with QT prolongation
Side effects: moderate sedation, hypotension, EPS, CNS effects, and mild anticholinergic symptoms
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Benzodiazepines
Lorazepam effectively provides emesis control, sedation, anxiety reduction, and amnesia when used in combination with a glucocorticoid and serotonin 5-HT3 receptor antagonist (can cause ischemic colitis).
Promethazine (Phenergan)
Category: Phenothiazines
MOA: blocks H1-receptor sites and inhibits CTZ
Onset: 15-60 minutes (oral); 20 minutes (IM); 3-5 minutes (IV)
Duration: 4-6 hours (oral, IM, IV)
*— Treats/prevents motion sickness, N/V and sedation induction
— A CNS depressant and an additive if taken with EtOH, narcotics/opiates, sedative-hypnotics, and general anesthetics
— Anticholinergic effects increase when combined with antihistamines (e.g. atropine)
Side effects: have antihistamine + anticholinergic properties, watch for EPS and CNS effects (restlessness, weakness, systolic rxns, agitation)
Contraindications: Narrow angle glaucoma, intestinal obstruction, blood dyspraxia’s, liver dysfunction, COPD
Serotonin antagonists for Antiemetics
Ondansetron (Zofran), granisetron (Kytril), dolasetron (Anzemet), palonosetron (Aloxi)
— work on 5H-T receptors
— Best used for patients CINV, PONV, radiation therapy NV, viral gastritis NV & NVP (pregnancy)
Serotonin antagonists benefits r/t nausea, vomiting + side effects
Benefits: reduces N/V r/t chemotherapy, post-op, radiation, viral gastritis, & pregnancy
Common side effects: headache, diarrhea, dizziness, and fatigue
These drugs DO NOT block dopamine so will not cause EPS effects
These drugs can also prolong the QT measurement —> TORSADES de Pointes
— Antidote: Magnesium IV
Glucocorticoids (corticosteroids) for N/V
Dexamethasone (Decadron)
Methylprednisolone (Solu-Medrol)
Administered IV
Effective in suppressing emesis associated with cancer chemotherapy
NOTE: Because these are administered IV and for only a short while, side effects normally associated with glucocorticoids are minimized
IBD vs. IBS
IBD = inflammatory bowel disease
— electrolytes, biologic? Med, malabsorption
e.g. ulcerative colitis, celiac, crohn’s
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IBS = irritable bowel syndrome
— no inflammation
— usually diet/stress-related
— C(constipation predominant; don’t poop for 2 weeks) | D(diarrhea predominant)
Diphenoxylate with Atropine
Class: Antidiarrheals CSS V
Dose: initially, 2 tabs (2.5mg diphenoxylate, 0.025mg atropine each tablet); MAX = 8 tablets
MOA: inhibits gastric motility by exerting effect on smooth muscle cells of GI tract
Therapeutic effects: Tx diarrhea by slowing intestinal motility
Contraindications: severe diarrhea d/t pseudomembranous colitis; Increased CNS depression when drinking EtOH, antihistamines, opioids, sedative-hypnotics; MAOIs = may enhance HTNive crisis
Labs to check: increased serum liver enzymes, amylase
S/Eff: drowsiness, dizziness, confusion, euphoria, H/A, restlessness, abd pain, N/V, flushing, urine retention
A/Eff: angioedema, pancreatitis, tachycardia, lieu’s, toxic mega colon
Differentiate the actions and side effects of antiemetics, emetics, antidiarrheals, and laxatives
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Chapter 42, objective #2
Apply the nursing process for the patient taking antiemetics, antidiarrheals, and laxatives
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Chapter 42, objective #3
What is PUD and it’s causes?
Peptic Ulcer Disease (PUD)
— Group of upper GI disorders characterized by varying degrees of erosion of the gut wall
— Develops when aggressive factors outweigh defensive factors
Difference b/w aggressive factors vs. defensive factors related to PUD
Aggressive factors: H pylori, NSAIDs, acid, pepsin, hyperstimulative
—purpose: disorders stimulates the gut causing issues
Defensive factors: mucus, bicarb, submucosal blood blow, prostaglandins
— purpose: to keep/maintain gut health
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NOTE: NSAIDs inhibits prostaglandins =setting person up to development of erosions in the gut wall
H. pylori + how to treat
most common cause of PUDs
— Gram negative bacillus that can colonize the stomach and duodenum
— 60-75% of patients with peptic ulcer disease (PUD) have it
— Tx: control acid production, but will not cure, but trying to create conditions conducive to stomach; e.g. Take an anti acid (will neutralize acid in stomach and allow healing to occur) but will not FIX the hyper acidity problem that originally caused the problem — use antibiotics in conjunction to get RID of H.pylori and CURE problem
Examples of peptic ulcers
Esophageal ulcer
Results from reflux of acidic gastric secretions into esophagus due to an incompetent cardiac sphincter
Gastric ulcer
Results from a breakdown of gastric mucosal barrier
Duodenal ulcer
Results from hypersecretion of acid
Stress ulcer
Results from trauma, burns, major surgery
Stomach diagram
— Cardiac sphincter = top of stomach = lower esophageal sphincter (LES)
— Pyloric sphincter = @ end of stomach
— duodenum = beginning of small intestine
— stomach = starts digestion and makes hydrochloric acid
— lower stomach used to low pH
— small intestine = not used to low pH ( if lots of acid in tummy and moves to duodenal —> duodenal ulcers
Once you impair the mucosal barrier
Pepsin = used to start digestion of protein (stomach muscle is made of protein)
Heartburn = fluid refluxing through cardiac sphincter/LES and damaging the esophageal mucosa (not made for acidic pH)
Stomach can develop erosion = more difficult to heal in presence of more acid and pepsin
Differentiate contraindications to the use of antiemetics, emetics, antidiarrheals, and laxatives
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Chapter 42, objective #4
Differentiate between peptic ulcer, gastric ulcer, duodenal ulcer, and gastroesophageal reflux disease (GERD)
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Chapter 43, objective #2
Explain the predisposing factors for peptic ulcers
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Chapter 43, objective #1
What is GERD? Cause? Triggers?
GERD Gastroesophageal Reflux Disease aka reflux esophagitis
— inflammation of the esophageal mucosa caused by reflux of gastric content into the esophagus
Cause: incompetent lower esophageal sphincter — cannot maintain it’s competency (can’t stay shut very well), will allow reflux, creating sensation of heartburn of reflux esophagitis
Triggers: EtOH, smoking, stress, spicy foods
Explain the differences between enteral nutrition and parenteral nutrition
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Chapter 14, objective #1
— Nasogastric tube – can be used to give nutrition or empty stomach contents (gastric decompression)
— Nasoduodenal or nasojejunal tube – goes through pyloric sphincter; weighted Dobhoff tube; smaller bore and more flexible than NG; decreases aspiration risk; clogs easily!
— Gastrostomy and PEG (percutaneous endoscopic gastrostomy) – both gastric feeding tubes; flexible, larger bore than Dobhoff; difference is surgeon puts in gastrostomy tube; GI specialist can take patient to endoscopy and insert PEG tube; so PEGs are cheaper and require less anesthesia then gastrostomy tubes
— Jejunostomy tube – bypasses stomach and still can be used for feedings or intestinal decompression.
