Term
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Definition
- hollow muscular tube that begins at the mouth and ends at the anus; encompasses the pharynx, esophagus, stomach, small/large intestine
- primary functios are to digest & absorb foods & fluids & excrete metabolic waste
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Term
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Definition
- affect the mouth or esophagus, compromising a pt's ability to ingest food
- usually occur secondary to a primary disease (e.g. cancer, acquired immunodeficiency syndrome (AIDS), diabetes) or result from poor dentition
- stomatitis, esophagitis, achalasia (slow transit of food from mouth to stomach), esophageal hiatal hernia & oral & esophageal cancers are disorders of food intake
- risk factors: presence of primary disease, malnutrition, use of tobacco
- some disorders, such as hiatal hernia & achalasia, have no specific risk factors
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Term
| disorders of digestion & absorption |
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Definition
- disorders of digestion & absorption affect the stomach and small intestine, hindering the body's ability to break down food & absorb essential nutrients
- gastritis, peptic ulcer disease, gastroenteritis (stomach flu), malabsorption syndrome, stomach cancer & cancer of the small intestine are disorders
- ulcerative colitis and regional enteritis (Crohn's disease) are considered disorders of digestion/absorption as well as elimination
- risk factors: genetic predisposition, stress, administration of certain drugs, use of tobacco
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Term
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Definition
- disorders of elimination affect the large intestine, rendering a person unable to maintain a normal elimination pattern
- these may occur alone, as a sequal to another disease, or as a result of admin certain drugs
- disorders in elimination result in abnormal amts or constituents of stool
- ulcerative colitis, regional enteritis (Crohn's), irritable bowel syndrome (exculsion diagnosis), diverticulitis, & cancer of the large intestine
- risk factors: presence of cancer, genetic predisposition, stress, ingestion of foods that do not agree w/ the individual, admin of certain drugs, use of tobacco
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Term
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Definition
| always made worse by the use of tobacco & ETOH; avoiding these substances is part of the treatment for any GI disorder |
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Term
| physiological responses to gastrointestinal dysfunction: |
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Definition
- Halitosis: foul smelling breath; may indicate periodontal or oral infectious process
- dysphagia: difficulty swallowing; may result from mechanical problem (e.g. neoplasm, surgery) or occur secondary to neurologic damage or dysfunction (e.g. CVA)
- Odynophagia: painful swallowing; important marker for infection or disease
- Pyrosis (heartburn): burning sensation usually in midsternal area caused by reflux of gastric contents into esophagus
- dyspepsia (ingestion): feeling of discomfort during digestive process, or inability to digest food secondary to GI disorder
- anorexia: loss of appetite, common complaint associated w/ GI disease; causes can include: neoplastic process ,anxiety, pain, depression, infection, or constipation
- satiety: feeling of fullness, at times beyond the point of satisfaction
- malabsorption: inability to absorb nutrients secondary to GI disorder or surgery
- altered bowel sounds: indicate passage of air/fluid in GI tract; diminished or absent after abdominal surgery or hyperactive/high pitched as a result of hypermotility of GI tract
- melena: black or tarry stools indicating presence of blood
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Term
| peptic ulcer disease (PUD) |
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Definition
- chronic condition characterized by ulceration of the gastric mucosa, duodenum; less frequently of the lower esophagus & jejunum
- duodenal ulcers are 3x more prevalent than gastric ulcers & usually occur between 20-50yrs of age
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Term
| pathophysiology of peptic ulcer disease |
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Definition
- not fully understood
- possible contributing factors:
- mucosal breakdown secondary to infection w/ gram-neg Helicobacter pylori
- genetic predisposition
- tobacco use
- ingestion of food/drugs that injure or alter gastric mucosa or increase HCL production (e.g. ASA, corticosteroids, caffeine, spicy foods)
- stress
- presence of disease that alter gastric secretion (e.g. pancreatitis, Crohn's)
- increased Cl secretion
- inagdequate mucosal defense against gastric acid
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Term
| protecting factors of PUD |
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Definition
mucus bicarbonate prosteglandins |
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Term
| treatment approaches for PUD |
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Definition
- eradicating H.pylori infection
- reducing secretion of gastric acid or neutralizing the acid after it is released
- providing agents that protect the gastric mucosa from damage
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Term
| regulation of gastric acid secretion |
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Definition
- gastric acid secretion by parietal cells of the gastric mucosa is controlled by acetylcholine, histamine, prostoglandins E2 & I2 & gastrin
- receptor-mediated binding of Ach, histamine, or gastrin results in activation of a H/K-APTase proton pump that secretes HCl into the lumen of the stomach
- in contrast, receptor binding of prostaglandins E2 & I2, diminishes HCl production
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Term
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Definition
- H.pylori is a gram-neg, curved or spiral bacterium found primarily in the mucous layers of the gastric antrum of humans
- produces significant amts of urease, which catalyzes the hydrolysis of urea into ammonia & CO2; ammonia neutralizes gastric acid & is toxic to gastric epithelial cells; also, stimulates gastric epithelial cells to release proinflammatory substances that participate in the initiation of inflammation & tissue injury
- most common chronic bacterial infection in humans & is a well-established primary causative factor of PUD; has been linked to other types of gastritis, gastric adenocarcinoma, & low grade gastric lymphoma arising from mucosa-associated lymphoid tissue (MALT)
- H.pylori associated PUD afflicts about 10% of US popl'n
- mode of transmission is not known; thought to be person to person through fecal-oral or oral-oral contact, gastric routes, or hands (so, not blood)
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Term
clinical syndrome: helicobacter pylori |
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Definition
- factors that determine disease outcome - not fully understood; estimated that only 1 in 6-7 infected people will develop PUD; risks of gastric adenocarcinoma & gastric lymphoma are even lower
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Term
| treatment for helicobacter pylori |
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Definition
- a combo drug regimen; no regimen is ideal, and no regimen can eradicate the infection in 100% of treated pts
- triple regimens comprising a PPI, clarithromycin & amoxicillin are regarded as first-line; should be used for 10-14 days (4 tablets BID)
- 7-day & 3-day regimens are awaiting FDA approval
- pts allergic to PCN-combo of PPI, clarithromycin & metronidazole; this is associated w/ higher incidence of side effects; moreover, if this tx fails, H.pylori may be resistant to both clarithromycin & metronidazole after tx; therefore, not recommended for routine use
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Term
| gastroesophageal reflux disease |
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Definition
- constellation of sx caused by the reflux of acidic gastric content into the esophagus
- contributing pathophysiologic mechs: (H.pylori +)
- decreased esophageal clearance
- incompetence of the lower esophageal sphincter (LES)
- impaired resistance of esophageal mucosa
- delayed gastric emptying
- presence of hiatal hernia
- small amt of physiologic reflux (<5.5% of the time) - normal. in majority of GERD pts, pathology's cause is not acid overproduction but length & frequency of esophageal acid exposure
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Term
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Definition
- GER: passage of gastric contents into the esophagus
- regurgitation: passage of gastric contents into the oropharynx
- emesis: expulsion of gastric contents from the mouth
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Term
physiologic reflux vs. pathologic reflux |
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Definition
- physiologic reflux: reflux that does not compromise health or well-being (the usual cause in infancy) - if baby is not gaining weight, the it could be a problem
- pathologic refulx: reflux associated w/ esophagitis, growth failure, respiratory disease, apnea, or psychosocial dysfunction
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Term
| clinical presentation of gastroesophageal reflux disease |
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Definition
- heartburn, acid regurgitation, epigastric pain = most common
- others: belching, dysphagia, odynophagia, cough, hoarseness, nausea, noncardiac chest pain, respiratory complaints: asthma, chronic sinusitis
- alarm symptoms: serious damage may have already occurred if the followin are present:
- dysphagia: difficulty w/ swallowing
- bleeding: vomiting blood or having tarry, black BMs
- choking: sensation of acid refluxed into the windpipe causing SOB, coughing, or hoarseness
- weight loss
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Term
| management of gastroesophageal reflux disease |
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Definition
- individualized depending upon severity of symptoms; goals are to:
- relieve symptoms
- heal esophagitis if present
- prevent complications
- maintain remission
- treat complications
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Term
gastroesophageal reflux disease: tx in infants |
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Definition
- physiologic GER (infancy):
- smaller, more freqeunt feedings
- more frequent burping
- positioning (up at 30 degrees)
- thickening of feedings (some advise adding rice cereal to formula); will eat less volume
- elemental formula (simple amino acids to baby doesn't need gastrin to break down anything into amino acids); very expensive and not sure if it's necessary
- only 10% of babies won't correct this by 18yrs old
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Term
| lifestyle modifications for GER |
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Definition
- diet modifications
- avoid food that aggrevate symptoms (peppermint, chocolate, citrus juice, tomatoes, coffee, smoking, ETOH, fatty foods, spicy foods, onions) - activate gastrin pathway
- avoid eating 2-3hrs before bed
- avoid large meals & quantities of liquid
- avoid medications that lower lES tone or decrease motility
- elevate head of bed
- curtain smoking & ETOH intake
- avoid stooping & bending
- do not exercise immediately after eating
- avoid tight-fitting clothing
- reduce weight, if overweight
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Term
| pharmacodynamics of antacids |
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Definition
- gastric antacids are weak bases that react w/ gastric HCl to form salt & water: net result = increased gastric pH
- goal of antacid tx: pH between 3-3.5 (from original 1.8)
- can effectively reduce the recurrance rate of peptic ulcers when used regularly in doses that significantly raise the stomach pH
- acid-neutralizing ability of an antacid depends on its capacity to neutralize gastric HCl & on whether the stomach is full or empty (food delays stomach emptying allowing more time for the antacid to react)
- since Ca salts stimulate gastrin release, use of Ca-containing antacids may be counterproductive
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Term
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Definition
magnesium hydroxide (Milk of Magnesia) aluminum hydroxide (AlternaGEL, Amphogel) aluminum/magnesium cpds (Maalox, Riopan) aluminum hydroxide & magnesium hydroxide (Maalox II, Mylanta II) calcium carbonate (TUMS) sodium bicarbonate |
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Term
| pharmacokinetics of antacids |
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Definition
- duration of action is only 2hrs; need to be taken frequently
- differ mainly in their absorption & effects on stool consistency
- Mg & Al compounds are not as absorbed from the bowel
- Mg hydroxide has strong laxative effects
- Aluminum hydroxide has constipating actions; reacts w/ HCl to form an insoluble cpd
- both calcium carbonate & sodium carbonate are absorbed from the gut; b/c of their systemic effects are less popular as antacids that Mg & Al salts
- sodium bicarb is used to treat metabolic acidosis; not recommended for tx of PUD
- calcium carb's side effects: nephrolithiasis & constipation
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Term
| contraindications of antacids |
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Definition
- pts w/ any known allergy to any antacid component
- caution in pts w/ any conditions that electrolyte or acid-base imbalances, GI obstruction, or renal dysfunction may exacerbate (esp Al)
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Term
| drug interactions with antacids |
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Definition
- presence of antacids in the stomach may impair absorption of many other drugs; advisable to avoid concurrent admin of antacids & other drugs; by binding to drugs (e.g. tetracycline) Al cpds can form insoluble complexes that are not absorbed; on the other hand, antacids can increase the rate of absorption of some drugs e.g. levodopa
- when antacids are taken w/ enteric-coated meds, coating is disintegrated & drug is released prematurely in the stomach
- Ca & Mg preps exacerbate the action of digitalis (secondary to effect of K) - b/c Mg & K always go the same way (Ca goes opposite)
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Term
| adverse effects of antacids |
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Definition
- Al cpds: constipation, delayed gastric emptying & hypophosphatemia
- Ca cpds: costipation, hypercalcemia & renal calcuri
- Mg cpds: diarrhea, w/ resultant hypokalemia, iron deficiency & hypermagnesemia
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Term
| nursing considerations of antacids |
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Definition
- onset of drug action is within 5-15min & duration is 2 hrs (short 1/2 life, so usually for short-term issues)
- admin at least 1 hr before or 2 hrs after any other PO drug to ensure adequate absorption
- monitor electrolytes of the pt who is taking antacids for early detection of an electrolyte imbalance
- instruct pt to chew antacids thoroghly and follow w/ one glass of water to ensure it reaches stomach f or direct action and to avoid development of intestinal concretions calculi
- instruct pt to shake liquid preps before pouring
- acid rebound may be present & repeated use for 1-2wks might cause a rebound acid stim action, quickly leading to development of chronic antacid use
- pts who receive large quantities of antacids over prolonged period or those who are on a diet that is low in phosphorus (while taking antacids continuously) may develop hypophosphatemia within 2 wks
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Term
| histamine2-receptor antagonists |
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Definition
famotidine (Pepcid) - block histamine2-receptor sites in the gastric mucosa, thus reducing secretion of HCl
- capable of reducing more than 90% of basal secretions of gastric acid after a single dose (96-99%) - comparable to more expensive proton pump inhibitor
- PO absorption is good; routes of admin: PO/IV
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Term
| contraindications & drug interactions with histamine2-receptor antagonists |
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Definition
- cimetidine: contraindicated in preg/lactation & liver impairment
- caution in pts w/ renal insufficiency & elderly (dose adjustment recommended)
- cimetidine: potent inhibitor of enzymes of the P-450 system & can slow metabolism (and thus potentiate action) of several drugs (e.g warfarin, phenytoin, diazepam)
- famotidine: few drug interactions; do not exhibit inhibitory function on the P-450 system
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Term
| adverse effects of histamine2-receptor antagonists |
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Definition
- prolonged therapy w/ cimetidine associated with: confusional state, psychotic symptoms, nausea, headahce, reversible gynecomastia
- can increase stomach pH sufficiently to allow for outgrowth of microorganisms (bacteria, candida) - not signif. unless has secondary conditions
inform pt to seek help if symptoms do not subside within 1-2mo of therapy |
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Term
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Definition
omeprazole (Prilosec), lansoprazole (Prevacid), rabeprazole (Aciphex), pantoprazole (Protonix) IV, esomeprazole (Nexium) - act directly on the secretory surface of the gastric parietal cells
- become active in an acidic environment & irreversibly inhibit the hydrogen-potassium ATPase gastric enzyme system, which catalyzes the final step of the acid production in the stomach
- most effective agents: can essentially inhibit 100% of gastric acid secretion with a single daily dose; their antisecretory effect lasts up to 72hrs (so, better for noncompliant pts)
- most rapid acting (but very expensive)
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Term
| pharmacotherapeutics for proton pump inhibitors |
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Definition
- PUD
- GER
- erosive esophagitis
- Zollinger-Ellison syndrome & other hypersecretory syndromes
- successfully used w/ antimicrobials regimens to eradicate H.pylori
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Term
| contraindications/drug interactions for proton pump inhibitors |
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Definition
- hypersensitivity
- preg cat C
- caution in hepatic impairment (dose adjustment)
- absorption of concurrent drugs may be decreased b/c of alteration of gastric pH (e.g. Fe, digoxin, ampicillin)
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Term
| side effects of proton pump inhibitors |
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Definition
- as a group well tolerated
- HA, diarrhea, nausea, emesis (rare w/ short term use)
- can increase stomach pH sufficiently to allow for outgrowth of microorganisms (bacteria, candida)
- avoid opening, chewing, or crushing capsules; they should be swallowed whole for therapeutic effect; lansoprazole capsules can be opened and sprinkled on soft food
- advise pt to take PPIs before meals on empty stomach to ensure drug efficacy
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Term
| safety of long term PPI treatment |
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Definition
- incidence & spectrum of adverse events similar to H2RAs
- no evidence that long term PPI tx promotes development of: gastric carcinoids, atrophic gastritis, gastric adenocarcinoma
- risk ofenteric infection does not seem to be a clinical problem
- absorption of fats & minerals unimpaired
- prob no need to monitor B12 levels in routine practice
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Term
mucosal protectant/citoprotective agent: sucralfate (Carafate) |
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Definition
- complex of Al(OH)3 & sulfated sucrose, a small, poorly soluble molecule that polymerizes in the acid environment of the stomach; this polymer binds to injured tissue & forms a protective coating over ulcer beds; creates a physical barrier that protects the ulcer form gastric acid, pepsin & bile
- its action is local rather than systemic; too insoluble to have significant systemic effects
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Term
| pharmacokinetics of sucralfate |
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Definition
- contains an aluminum complex
- only minimal amt is absorbed through GI tract
- 90% of the paste is excreted in f eces
- do not admin w/ antacids; gastric acid is needed to activate sucralfate
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Term
| pharmacotherapeutics of sucralfate |
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Definition
- used to protect the wall of the GI tract from ulceration or injury from excess acid (hyperacidity)
- to prevent or treat ulcer disease & used for short-term tx (up to 8wks) of duodenal & gastric ulcers
- contraindicated in kidney impairment b/c Al is not removed via the impaired kidneys or dialysis
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Term
| drug interactions/adverse effects of sucralfate |
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Definition
- may decrease absorption of other drugs; should be given 2hrs apart from other drugs
- very well tolerated
- constipation & dry mouth = most common
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Term
| nursing considerations for sucralfate |
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Definition
- give PO in either tablet or suspension form
- admin on an empty stomach (1 hr before meals and at bedtime) - or it won't form polymer
- give other PO meds 2 hrs before sucralfate
- continue therapy even when symptoms of ulcer disappear unless healing canbe confirmed by endoscopy
- advise pt to avoid smoking & spicy foods that might aggravate ulcer
- monitor pt w/ chornic renal failure for increasing signs and symptoms of Al toxicity: acute dementia, osteomalacia, bone pain with or without fractures
- admin antacids 30 min before or after sucralfate
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Term
prostoglandin misoprostol (Cytotec) |
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Definition
- synthetic protaglandin E1 that decreases gastric acid secretion & helps protect the GI mucosa
- may be used in pts on NSAIDs & those who are at risk or NSAID-induced gastric ulcers; usually used concurrently as long as the pt is on NSAIDs
- NSAIDsinhibit prostaglandin production, which leads to a decrease in bicarbonate & mucus production, which increases the risk of gastric mucosal injury from NSAIDs
- also produces uterine contractions
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Term
| contraindications of prostoglandins (misoprostol) |
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Definition
- hypersensitivity
- renal dysfunction
- contraindicated in pregnancy b/c partial or complete abortion & uterine bleeding may result
- contraindicated in lactation & kids
- antacids may reduce the action of misoprostol
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Term
| adverse effects of prostoglandin (misoprostol) |
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Definition
- well tolerated
- most common: diarrhea & abdominal pain; diarrhea usually dose-related, mild & self-limiting (resolving in about 8 days)
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Term
| nursing considerations for prostoglandin (misoprostol) |
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Definition
- no dose reduction is suggested for pts w/ renal impairment or older pts, unless dose is not tolerated
- admin ac & ghs w/ food to prevent GI discomfort &diarrhea
- avoid admin w/ Mg-containing antacids, which may increase incidence & severity of diarrhea
- advise pt w/ childbearing potential to avoid pregnancy & use effective contraception
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Term
prokinetic drugs/GI stimulants metoclopramide (Reglan) |
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Definition
- increase motion & movement through the GI tract & aceleration of GI emptying; no effect on peristaltic movement in the colon
- cholinergic drug that stimulates motility of the upper GI w/o increasing gastric, biliary &pancreatic secretions
- also has an antiemetic effect
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Term
| pharmacotherapeutics of prokinetic drugs/GI stimulants (metoclopramide) |
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Definition
- GERD
- gastroparesis (slow motility)
- postoperative GI hypomobility
- postoperative & chemotherapy nausea & emesis
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Term
| contraindications of prokinetic drugs/GI stimulants (metoclopramide) |
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Definition
- GI obstruction, hemorrhange, perfusion
- hypersenstivity
- epilepsy
- those receiving other drugs that are likely to cause EPS
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Term
| drug interactions & adverse effects of prokinetic drugs (metoclopramide) |
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Definition
- ETOH & other CNS depressants: increased sedation
- phenothiazins: increased risk of EPS
- anticholinergics & opiate analgesics: antagonize the therapeutic effect & decrease GI motility
- most common adverse effects: drowsiness, restlessness, fatigue, diarrhea & EPS, particularly acute dystonic rxns
- EPS usually subsides 2-3mo after d/c
- other adverse effects: dizziness, visual disturbances, confusion, depression (b/c blocking dopamine receptors), insomnia, suicidal ideation, galactorrhea, gynocomastia
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Term
| nursing considerations for prokinetic drugs (metoclopramide) |
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Definition
- PO 30 min before meals & at bedtime
- dilute IV doses above 10mg or more in 50ml of parenteral sol'n & give slowly over 15 min or longer; 10mg or less may be given over 1-2min
- protect IV metoclopramide from light w/ aluminum foil or other protective covering
- monitor fo EPS, which are most likely to occur early in tx, at high doses, in pts who are dehydrated, or in pediatric and young pts
- benadryl may be given IM to reverse EPS
- monitor for tardive dyskinesia symptoms, including involuntary movements of the tongue, mouth, or jaw, face or extremities; potentially irreversible so withhold and notify PCP
- have adequate fluid intake
- avoid ETOH & other depressants
- monitor blood sugar & s/s of hypoglycemia
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Term
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Definition
- symptom rather than disease
- historically defined as pasage of less than 3BMs/week (medical diagnosis - not pt's word)
- ROME II diagnostic criteria: two or more of the following for at least 12 wks in the last 12mo - strainin, lumpy or hard stools, sensation of incomplete evacuation, sensation of obstruction, manual maneuvers (all in more than 25% of defecations), loose stools not present
- for infants/young kids, at least 2 wks of pepple-like, hard stools for the majority of stools or firm stools two or fewer times/wk
- most pts are found to have no discernible cause for constipation & are labeled as having a chronic functional or idiopathic constipation
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Term
treatment for constipation: laxatives |
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Definition
promote bowel evacuation; generally glassified by simplified mechanism of action: - stimulant laxatives
- bulk-forming laxatives
- lubricant laxatives
- hyperosmotic laxatives
- saline laxatives/saline cathartics
- stool softener/surfactant laxatives
- (cathartics = stronger agent, producing semi-liquid or liquid stools)
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Term
| stimulant/irritant laxatives |
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Definition
senna (Senokot) - cathartic effect: stimulate peristalsis by irritating the lining of the small & large intestinal wall
- strongest & most abused; results in 6-12hrs after PO admin; 15-60min after PR (rectal) admin (dose dependent)
- certain foods- prunes, raisins, rhubarb, pears-contain organic acids that cause irritation of the intestinal mucosa & stimulation of peristalsis
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Term
| contraindications/precautions with stimulant/irritant laxatives |
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Definition
- pts w/ hypersensitivity, undiagnosed abdominal pain, ulcerated hemorrhoids, Crohn's, ulcerative colitis, and other chornic inflammatory bowel diseases
- b/c cascara sagrada contains ETOH, it should be avoided in pts w/ a known intolerance to ETOH
- enteric coating of ex-lax is prematurely removed when taken concurrently within 1hr of antacids or dairy products
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Term
| adverse effects of stimulant/irritant laxatives |
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Definition
- most common: abdominal cramping from increased paristalsis
- excessive & prolonged use may lead to dependence; if drug is stopped, pt is likely to experience constipation (so, discontinue after 3-5 days)
- Senokot may color uring and feces a reddish or yellow-brown
- castor oil is used less frequently b/c of high incidence of numerous adverse effects such as severe abdominal pain
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Term
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Definition
psyllium (Metamucil) - stimulate peristalsis by adding bulk to stools; results usually occur in 24hrs & may take up to 2-3days to establish regularity
- combine w/ water in intestine to form a gelatinous or viscous stool; the stool expansion causes the colon to distend & stimulate peristalsis
- bulk laxatives are indigestible, mild & less apt to habit-forming than other laxatives
- no interference w/ absorption of nutrients
- considered the safest laxative, produce the same natural action as do 6-10g of fiber/day
- should be taken w/ 8oz of fluid; the mixture should be taken immediately b/c it will congeal in a few min
- can be used for diarrhea or constipation
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Term
lubricant laxatives: mineral oil (elderly pts still often use) |
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Definition
- coats fecal material w/ a film, which prevents the reabsorption of water through the colon; softens the stool & lubricates the intestinal wall, w hich facilitates the smooth passage of feces
- absorption of food & fat-soluble vits (A,D,E,K) may be reduced if taken longer than 2 wks
- most dangerous adverse effect = lipid pneumonia, when mineral oil droplets are aspirated
- prolonged use may lead to bowel-elimination dependence
- should be taken after the evening meal & qhs to avoid loss of fat-soluble vits; should be taken at least 2hrs after meals to avoid interference w/ digestion of food
- b/c aspiration of mineral oil appears to be greatest during sleep, it should be given well before bedtime to prevent aspiration & resultant lipid pneumonia
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Term
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Definition
polyethylene glycol-electrolyte soln (GoLYTELY) - hypertonic drugs that draw water from surrounding tissue into the intestine, thereby creating an increased osmotic pressure in the bowel; the fluid moves from extracellular compartments through intestinal mucosa into the bowel; additional fluid changes the stool consistency to liquid, distends the bowel, stimulates stretch receptors & peristalsis
- oral hyperosmotic laxatives should not be given within 1hr of other oral meds b/c the increased transit time of the laxatives will interfere w/ the absorption of other drugs
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Term
| hyperosmotic laxatives are often used to ____ |
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Definition
| cleanse the entire digestive tract for diagnostic purposes (e.g. colonoscopy), flush poisons from the system, or remove parasites; inappropriate for long-term use |
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Term
| _______ gives the best & most complete evaculation of the GI tract of all of the available laxatives |
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Definition
polyethylene glycol-electrolyte soln (GoLYTELY) admin PO over 3-hr period and may be admin in 240cc (8oz) q10min; this should begin about 4-5hrs before exam or procedure; when the pt is unable to take PO, it may b e admin through a NG tube at a rate of 20-30cc/min; admin at home: 8oz every 10min until all 4L are taken; onset of action is 30min-3hrs for PO |
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Term
stool softeners: docusate sodium, docusate calcium, docusate potassium |
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Definition
- not considered to be laxatives in the truest sense
- surface-active agents that emulsify & wet the stool by permitting water to penetrate & soften the stool for easier passage
- used to prevent constipation or two soften stool for a wide range of conditions in which straining of stool is contraindicated (e.g. cardiac disease or after rectal surgery)
- can be safely used for long-term management of chronic constipation, esp when the cause is a low-fiber diet; they are the least harmful of laxatives b/c they are less habit-forming & do not inhibit absorption of certain nutrients
- full effect may take up to 3 days at start of tx; on daily basis, work overnight
- caps and tabs must be swallowed whole & not chewed or crushed; instruct pt to take PO dose w/ full glass of water
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Term
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Definition
- acute diarrhea: more frequent, looser than normal stools for less than 2 weeks; objectively: 200mg+ of stool output/day; often other GI s/s
- persistent diarrhea: >14days
- chornic diarrhea: duration of at least 1mo
- pathogens not detected in over 50% f cases; most cases resove in 48hrs
- persistent diarrhea should be tx secondary to danger of dehydration & electrolyte imbalances
- peds patients & elderly are at risk for most complications
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Term
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Definition
- locally acting or systemically absorbed drugs used to decrease the vol or fluidity of bowel contents or to decrease peristalsis for both acute & chronic diarrhea
- types of antidiarrheals:
- opioids: most effective agents
- absorbants
- intestinal flora modifiers
- bulk-forming agents
- antibiotics used in tx of infectious diarrhea
- corticosteroids in tx of diarrhea in inflammatory conditions
- overdose of antidiarrheals = constipation
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Term
antidiarreal agents: 1. opioids |
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Definition
lopermadine (Imodium, Kaopectate) diphenoxylate Hydrocholride w/ atropine sulfate (Lomotil) - slow intestinal motility or propulsion
- both are analogues of meperidine & have opioid-like actions on the gut, activating presynaptic opioid receptors in the enteric NS to inhibit ACh release & decrease paristalsis
- no or minimal potential for abuse b/c they do not cross the BBB
- side effects: drowsiness, abdominal cramps, dizziness, constipation
- since these can cause toxic megacolon, they should not be used inkids or pts w/ severe colitis
- caution in increased ICP, h/o drug abuse, and severe pulmonary disease
- ETOH & CNS depressants should be avoided during tx w/ opioid antidiarrheals
- response to tx should be noticeable 48hrs after tx begins; these are not innocuous drugs & not intended for prolonged use
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Term
antidiarrheal drugs: 2. absorbents |
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Definition
bismuth subsalicylate (Pepto-Bismol) - decreases fluid content in stool
- has demulcent, astrigent & anti-inflammatory properties; action may have direct antimicrobial & antiviral effects
- contains salicylates-contraindicated in kids (below 13) recovering from flu-type illnesses or chicken pox in which ASA is contraindicated (questionable assocation w/ Reye's syndome), in concomitant anticoagulant therapy, and in pts hypersensitive to ASA
- adverse effects: gray-black tongue or stools & constipation
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Term
antidiarrheal drugs: 3. intestinal flora modifiers |
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Definition
lactobacillus acidophilus (Lactinex, Bacid) - promotes growth of E.coli-normal bacterium present in the bowel
- restores gut flora depleted by abx therapy
- admin w/ milk, 2 hrs before or after intake of other meds
- know that adjunct of dietary regimen high in lactose & dexrose is also effective in providing recolonization of colon (ex: yogurt, milk, buttermilk)
- in pts w/ milk product allergies or intolerance, admin of Lactobacillus acidophilus may cause similar s/s of bloating, cramps, diarrhea, flatulence
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Term
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Definition
- n/v may occur in variety of conditions (e.g motion sickness, pregnancy, hepatitis, and as side effects of chemo)
- nearly 70-80% of all pts given chemo experience n/v
- emesis can produce dehydration, profound metabolic imbalances & nutrient depletion
- mech that trigger vomiting = vomiting reflex pathway
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Term
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Definition
- chemoreceptor trigger zone (CTZ)
- located in the area postrema (structure at caudal end of fourth ventricle)
- outside BBB - so it can respond directly to stimuli in blood re cerebrospinal fluid
- vomiting center
- located in lateral reticular formation of mediulla
- coordinates motor mech of vomiting
- vestibular system
- located in middle ear
- functions mainly in motion sickness
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Term
| considering the complexity of the mechs involved in emesis, the antiemetics represent a variety of classes: |
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Definition
- some act by inhibiting the chemoreceptor trigger zone in the medulla by blocking the action of dopamine (e.g. phenothiazines)
- other act by decreasing the sensitivity of the vestibular apparatus in the middle ear (e.g. antihistamines, anticholinergics)
- other agentsdo not act in either of these ways
- antiemetics should be admin before emetogenic tx; it is easier to prevent nausea than to treat it!
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Term
antiemetic drugs: phenothiazines/dopamine receptor antagonists agents |
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Definition
- prochlorperazine (Compazine) - tx of severe n/v
- promethazine (Phenergan) - tx of motion sickness & drug of choice for n/v of gastroenteritis
- trimethobenzamide (Tigan) - tx n/v of radiation therapy, in postoperative nausea, and gastroenteritis
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Term
antiemetic drugs: phenothiazines/dopamine receptor antagonists |
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Definition
- block dopamine receptors in the CTZ; dopamine is required for the conduction of impulses from excited afferent nerves to stimulate the medullar-vomiting center
- blocking dopamine receptors inhibits the stimulation of hte vomiting center & an antiemetic effect results
- used to manage nausea & emesis due to either ratdiation therapy or chemo, or do to the effects of toxins
- contraindicated in depression, severe liver & CV disease, pregnancy, and kids < 2y.o.
- may drug interactions: check before admin; additive hypotensive effects w/ ETOH, antihypertensives, CNS depressants
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Term
| adverse effects of phenothiazines/dopamine receptor antagonists |
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Definition
- major: EPS esp. w/ prolonged therapy; dehydrated pts are more likely to experience this
- dystonia
- akathisia
- psuedoparkinsonism
- tardive dyskinesia
- anticholinergic effects: dry mouth, flushing, blurred vision, tachycardia, photosensitivity, constipation
- agranulocytosis: rare
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Term
antiemetic drugs: serotonin receptor antagonists |
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Definition
ondansetron (Zofran) - selectively block central & peripheral serotonin receptors, producing an antiemetic effect
- most effective antiemetics for highly emetogenic chemo drugs
- can be used for postoperative n/v
- onset of action: 30min PO; IV route:1-3min; duration of action for PO drugs is 4-24hrs; peak is 30-90min
- HA-common side efect; may require analgesic for relief
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Term
miscellaneous antiemetics: scopolamine (Transderm Scop) |
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Definition
- works well for prevention/tx of motion sickness
- avail as .33mg patch
- adults: apply one patch in hairless area behind ear 4hrs prior to when antiemetic effect is needed
- replace after 3 days
- kids: not recommended
- side effects: anticholinergic
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Term
emetic agents (induce vomiting): ipecac (Ipecac Syrup) |
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Definition
- tx of oral poisoning or overdose; goal is to expel toxic substance from the body before material is absorbed from the GI tract
- stimulates the CTZ & acts directly on the gastric mucosa to stimulate vomiting
- emesis should not be induced when caustic substance (e.g. ammonia, bleach, drain opener, dye, battery acid, gasoline, kerosene, lighter fluid) have been ingested b/c will burn again on the way up
- OTC drug
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Term
| contraindications of emetic agents: |
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Definition
- cardiac dysfunction
- hypersensitivity
- depressed gag reflex
- deep sedation
- those in shock & coma
- drug interactions:
- milk & activated charcoal may inactive ipecac
- vegetable oil may delay absorption of ipecac
- when given w/ carbonated bevs, abdominal distention may occur
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Term
| adverse effects of emetic agents: |
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Definition
- diarrhea, drowsiness, mild GI upset
- adverse effects that may occur when ipecac is not vomited and is absorbed or when it is overdosed include: persistent vomiting, severe myopathy, tremors, cardiotoxicity, arrhythmias, chest pain, bradycardia, tachycardia, hypotension, fatal myocarditis, depression, coma
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Term
| nursing considerations for emetic agents |
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Definition
- follow w/ 8-16oz of water, dose may be releated in 20 min as needed (kids 1yr+, follow dose w/ 6-8oz of water, kids under 1yr, follow dose w/ 4-8oz of water)
- ipecac fluid extract is 14x stronger compared to the syrup and has caused death when mistakenly given as syrup
- when dose is not vomited and allowed to absorb, cardiotoxicity may occur (activated charcoal may inactive it)
- call poinson control before usuing ipecac
- give ipecac before activating charcoal
- when vomiting does not occur within 15-20min, the ER should be contacted immediately and dose of ipecac given should be recovered using gastric lavage and activated charcoal
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Term
antiflatulents simethicone (Mylicon) |
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Definition
- drug given to tx the discomfot of excessive gas in the GI tract
- gas is introduced to the body by:
- swalling air (primary reason)
- bacterial action leading to gas as byproduct
- diffusion of gas from blood stream into the GI tract
- avg of 7-10L of gas passes through GI tract, motof which is reabsorbed
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Term
| pharmacodynamics of antiflatulents |
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Definition
- changes the surface tension of gas bubbles in the stomach & intestine
- changed surface tension allows gas bubbles to stick together to form larger bubbles
- larger bubbles are easier than smaller ones to pass via peristaltic movement & motility in the GI tract through the mouth by belching or through the anus as flatus
- used in tx of flatulenceand of postoperative pts w/ gaseous distention
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Term
| nursing considerations of antiflatulents |
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Definition
(no contraindications, drug interactions, or adverse effects) - give PO and may include an antacid or antidiarrheal med
- mix w/ water, infant formula, or other liquid
- skae suspensions thoroughly
- tablets must be chewed before swallowing (not gelatin caps)
- assess bowel sounsd for presence of peristaltic activity before admin
- acitvity will increase peristalsis
- eating in an upright position and avoiding gas-producing foods or carbonated bevs may help decrease swallowing of air and encourage gas movement
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