Drugs for Gastrointestinal Problems Flashcards
The digestive system is composed of
The mouth espionage’s stomach intestines and accessory structures
Prostaglandins maintain good
Blood flow to the stomach
Antiemetic Drugs
Used to prevent and treat nausea and vomiting
Vomiting center in the brain
Direct-acting stimuli
Indirect-acting stimuli
Chemoreceptors trigger zone
-opioids, alcohol, certain antibiotics
Classes of antiemetic drugs
Serotonin receptors antagonists, substance P antagonists, phenothiazines, cannabanoids, promotility drugs, butyrophenones, and anticholinergics
Serotonin (5-HT3) Receptor Antagonists
Reduces or halts nausea and vomiting by blocking serotonin receptors in the intestinal tract and the CTZ so serotonin cannot activate these receptors
Uses of serotonin receptors antagonists
Prevent the nausea and vomiting from cancer chemotherapy, radiation therapy, and anesthesia-induced nausea and vomiting after surgery
Serotonin receptors antagonists
Dolasetron (Anzemet), ondasteron (Zofran, Zuplenz), palonosetron (Aloxi)
Dolasteron causes
Dizziness
Contraindications of dolasteron
Drugs that affect serotonin levels
Substance P/neurokonin1 receptor antagonists
Reduce or prevent immediate and delayed nausea and vomiting by blocking the substance P/neurokonin1 receptors in the CTZ, preventing both of these substances from binding to and triggering the CTZ
Aprepitant (Emend), rolapitant (Varubi)
Substance P/neurokinin1 receptor antagonists drugs
Apreptiant or rolapitant
Can be taken with corticosteroids to reduce symptoms of nausea and vomiting even further, may need to be taken in more frequent doses
Phenothiazines
reduce nausea and vomiting by blocking dopamine receptors in the CTZ
prochlorperazine (Compazine, Compro), promethazine (Pehnadoz, Phenergan, Promethegan)
Phenothiazine drugs
Adverse Reactions of phenothiazines
can cause hypotension, alcohol can increase drowsiness, can cause Parkinson’s disease-like tremors or gait changes and muscle spasms, or motor changes such as tongue rolling or lip smacking (ESPs)
neuroleptic malignant syndrome, a sudden increase in temperature
Cannabinoids
dronabinol (Marinol, Syndros), nabilone (Cesamet)
Use of cannabinoids
reserved for patients who continue to have nausea and vomiting who do not respond to other categories of antiemetics
Cannabinoid drug administration
typically given as solution or in liquid-filled capsules with the dosage individualized according to body surface area
first dose should be taken on an empty stomach 30 minutes before meals, after the first dose these drugs can be taken with food
Contraindications of cannabinoid drugs
alcohol, sedatives, or other CNS depressants
Promotility drugs
a class of drugs that increases contraction of the upper GI tract including the stomach and the small intestines; they do this by blocking dopamine receptors in the CTZ and the intestinal tract
Metoclorpramide (Reglan), trimethobenzamide (Tigan)
Promotility drugs
Nursing implications of promotility drugs
monitor for mood changes or restlessness, check vital signs regularly to assess for changes in blood pressure (decrease) because there is a risk for orthostatic hypotension, give these drugs at least 30 minutes before meals and at bedtime because these are times of increased potential for nausea
Serotonin receptors antagonist side effects
dizzinesss, headache, and drowsiness; some patients may experience changes in taste, heartburn, constipation or diarrhea
rarely a patient may experience chills with shivering
Adverse reactions of serotonin receptor antagonists
allergic reactions, dysrhythmias, and renal or liver damage
serotonin syndrome can occur
Serotonin receptor antagonist drug interactions
MAOIs, morphine, serotonin reuptake inhibitors
when combined with phenothiazine drugs, patient may experience cardiac dysrhythmias
Nursing implications of serotonin receptor antagonists
follow protocols very carefully to ensure adequate timing before the patient receives chemotherapy, monitor vital signs before and after giving the drug, ask patient about abdominal pain
Action and Uses of Substance P/NK receptor antagonists
block the substance P/NK 1 receptors in the CTZ, prevents triggering of the CTZ
reduce or prevent nausea and vomiting that results from cancer chemotherapy and after surgery
Side effects of Substance P/NK receptor antagonists
fatigue, diarrhea, nausea, and dizziness; patient may also experience mild hiccups, flatulence, and sweating
Adverse reactions of Substance P/NK receptor antagonists
neutropenia, angiodema, severe allergic reactions, and respiratory depression; anemia, thrombocytopenia
Drug interactions with Substance P/NK receptor antagonists
opioid drugs, drowsiness, increased dizziness, and sedation; use with benzos can increase CNS effects
The oral form of aprepitant should not be opened until
ready to prepare
Injectable fosaprepitant must be carefully prepared
do not shake this drug, gently swirl or invert the solution to gently mix
Phenothiazines are also recognized as
dopamine antagonists
Dopamine antagonists (phenothiazines) are approved to reduce nausea and vomiting from many problems except
the morning sickness associated with pregnancy
Phenothiazines side effects
blurred vision, drowsiness, dry mouth, and dizziness; can cause urine to change to a pinkish red color; sensitivity to sun exposure is common
Phenothiazines should be avoided in patients with
cardiovascular disease, can cause angina, tachycardia and/or orthostatic hypotension
Drug interactions of phenothiazines
metoclopramide (Reglan), can increase the effects of any other drug that affects dopamine (MAOIs, certain antidepressants), avoid benzos for patients who are taking carbidopa/levodopa for PD
Nursing Implications of Phenothiazines
carefully assess vitals, can cause a decrease in blood pressure and an increase in heart rate in some patients
avoid giving to patients with low blood pressure or who are dehydrated
assess for any occurrence of EPS
Avoid being overheated when taking
phenothiazines (decreases ability to sweat)
Photosensitivity can be caused by
phenothiazines
Cannabinoids action
THC reduces nausea by binding to both cannabinoid receptors in the CTZ and by preventing serotonin 5-HT3 from binding to its receptors in the CTZ
Cannabinoid side effects
a dose-related “high”, dizziness, anxiety, insomnia, difficulty concentrating, and mood changes; some patients may experience emotional lability (mood swings)
GI effects such as nausea, vomiting, and abdominal pain
orthostatic hypotension is more common in older adults
Adverse reactions of Cannabinoids
acute confusion, hypersensitivity, and seizure-like activity have occurred in some patients
rarely, hallucinations, excessive sweating, and fainting
use with caution with patients who have a history of substance abuse
Cannabinoid drug interactions
warfarin, calcium channel blockers, opioid agonists, and a variety of antiretroviral drugs
Patients taking dronabinol should avoid
grapefruit juice
Nursing implications of cannabinoids
can be taken using standard tablets and capsules or can be given as a liquid or in liquid-filled capsules (dose according to BSA)
Promotility drugs are also known as
prokinetic
Action of promotility drugs
increase contraction of the upper GI tract, by blocking dopamine receptors in the CTZ
These drugs work similarly to phenothizines but do not have the sedating effect
promotility drugs
Uses of promotility drugs
patients with postoperative nausea and vomiting, chemotherapy-induced nausea and vomiting, and GERD; may also be used in patients that have difficulties emptying stomach contents
Side effects of promotility drugs
drowsiness, dizziness, fatigue, and restlessness; visual impairment, urinary incontinence, and insomnia
Adverse reactions of promotility drugs
use with caution in patients with a history of depression, seizures, blood disorders, cardiac dysrhythmias, and heart failure; PD-like symptoms, EPS, and neuroleptic malignant syndrome
Promotility drug interactions
contraindicated in patients who are taking phenothizine drugs, typical and atypical antipsychotics and levodopa/carbodopa; use of these drugs with certain antidepressants can increase the risk for serotonin syndrome
Nursing Implications of promotility drugs
carefully monitor the patient for symptoms of restlessness, dizziness, and fatigue; monitor the patient for PD-like symptoms
Men taking promotility drugs may experience
gynecomastia
Drugs for peptic ulcer disease and gastroesophageal reflux disease
antacids, histamine H2 receptor antagonists, proton pump inhibitors, and cytoprotective drugs
Antacids
Aluminum hydroxide (Alternagel, Alu-cap), calcium carbonate (Rolaids Extra Strength, Tums, Caltrate, Maalox), magnesium hydroxide (Milk of Magnesia)
Antacid nursing implications
Often available as combination drugs, timing relating to meals and other drugs is very important, many drugs bind to antacids and lose effectiveness, antacids should be given 1 hour before any other drugs and 2 hours after drugs
Patients with heart failure or any other cardiac disease should avoid antacids high in sodium
Histamine H2 receptor antagonist drugs
famotidine (Pepcid AC, Pepcid), nizatidine (Axid), ranitidine (Zantac)
Nursing implications of histamine h2 receptor antagonists
OTC doses are typically about half the prescription drug doses. Patients who are taking these OTC drugs should not take them for more than 2 weeks without seeing a healthcare provider, as they may be experiencing a more significant issue. Monitor the patient for signs of restlessness or confusion b ecause these side effects may increase the risk for falls
Proton pump inhibitors function
these drugs help heal gastric ulcers and reduce symptoms of GERD by stopping the acid secretory pump that is located within the gastric parietal cell membrane. This helps reduce the amount of acid secreted into the stomach
Function of Histamine H2 receptor antagonists
these drugs bind to the H2 receptor in the stomach cells leading to a decrease in production of basal and nighttime gastric acid. They also decrease the amount of gastric acid that is released with meals and with substance such as caffeine
Proton pump inhibitor drugs
esomeprazole (Nexium), lansoprazole (Prevacid), omeprazole (Prilosec), pantoprazole (Protonix)
Nursing implications of Proton pump inhibitors
Give with full glass of water 30-60 minutes before meals for maximum benefit (read drug information carefully); OTC proton pump inhibitors should not be taken for more than 2 weeks because failure to relieve symptoms may indicate a more severe health problem; prescriptions of proton pump inhibitors may vary in length from 2 to 8 weeks depending on the patient’s presenting condition; teach patients it may take several days to experience relief once beginning proton pump inhibitors; if the patient has H. pylori bacteria in the stomach, the proton pump inhibitor will be combined with specific antibiotics to treat the infection so remind them to take the full prescription
Functions of cytoprotective drugs
these drugs protect the lining of the stomach and protect from further damage. When taken properly, some of these drugs can “stick” to the ulcerated areas in the stomach or duodenum to protect them from further damage and allow them to heal
Cytoprotective drugs
sucralfate (Carafate, Sulcrate), bismuth subsalicylate (Pepto-Bismol), misoprostol (Cytotec)
Nursing implications of cytoprotective drugs
do not give antacids within 30 minutes before or 1 hour after sucralfate because they decrease the effectiveness; do not crush or chew the tablets. For patients who are unable to swallow, dissolve in 10 mL of water. Shake the oral suspension well before giving to achieve a consistent dose of drug in solution. Carefully review dosages for bismuth subsalicylate before giving because this drug can be given for several conditions besides gastric distress. It can also be used for antibiotics properties. If patients do not receive relief from the recommended doses, make sure to contact the patient’s healthcare provider in case there is a significant underlying condition that needs treatment. Teach patients that bismuth subsalicylate can turn stools dark brown or even black while taking this drug. Taking too much bismuth subsalicylate can result in symptoms of aspirin toxicity. Encourage the patient to drink at least 2-3 L of liquid unless contraindicated because this drug can cause constipation. remember that misoprostol must never be given to pregnant women because it can cause uterine contractions
Patients with H. pylori ulcers are typically treated
by a combination of antimicrobial drugs and PPIs, treated for about 10 to 14 days with a standard triple therapy consisting of a combination PPI and two selected antimicrobials.
A standard quadruple therapy for H. pylori may require
a PPI and three antimicrobials
Antacids
neutralize hydrochloric acid and increase gastric pH
Expected side effects of antacids
diarrhea, constipation, loss of appetite, frequent burping, nausea and vomiting, fatigue, and weight loss
Adverse reactions of antacids
magnesium based antacids: hypermagnesia, muscle weakness, low blood pressure, low heart rate; calcium-containing antacids: bone pain, kidney stones and cardiac dysrhythmias; aluminium-containing antacids can cause mood changes, confusion, osteoporosis, and hypercalcemia
Drug interactions with antacids
a major concern is the impact on absorption of other drugs, space apart drug administration between prescription drugs and antacids
Expected side effects of histamine h2 receptor antagonists
headache, nausea, diarrhea, or constipation, and mild abdominal pain; some patients have mental status changes, including confusion, anxiety, or depression
Adverse reactions of histamine h2 receptor antagonists
severe reactions are rare and include severe allergic reactions, a variety of blood disorders, and cardiac dysrhythmias; patients may also be at risk for pneumonia
Drug interactions of histamine h2 receptor antagonists
can affect certain enzymes in the liver that metabolize drugs, which can affect how certain drugs are metabolized in the body, including warfarin, beta blockers, benzos, calcium channel blockers, and alcohol
H2 receptor blockers should be given
at meals and at bedtime
Proton pump inhibitors expected side effects
headache, mild abdominal pain, nausea, and vomiting, flatulence, and diarrhea or constipation; many patients experience increased sensitivity to light, and less common side effects include dizziness, anxiety, or mild rash; low vitamin b12 levels may develop in patients who have taken PPIs for more than 1 year
Adverse reactions of PPIs
pancreatitis, blood abnormalities, there is some concern that decreased calcium absorption in the stomach may place the patient at risk for osteoporosis and bone fractures with long-term use
Drug interactions of PPIs
inhibits certain enzymes in the liver that are involved in metabolizing other drugs. PPIs can decrease the effectiveness of warfarin, alprazolam, drugs given to treat TB, and certain drugs used to decrease blood cholesterol
Give PPIs
about 30 to 60 minutes before the first meal of the day
These drugs can “stick” to the ulcerated areas in the stomach or duodenum to protect them from further damage and allow them to heal
Cytoprotective drugs, aka Pepto Bismol, Carafate, and Cytotec
Misoprostol
is a synthetic prostaglandin with both an antisecretory and a mucosal protective action, indicated for use in patients who have gastric distress or ulceration secondary to the use of NSAIDs
Drugs for constipation and diarrhea
anticholinergic drugs, antispasmodic drugs, opioid agonists, bulk-forming drugs, emollients/stool softeners, stimulants, and osmotic laxatives
Bulk forming laxatives
relieve constipation by absorbing water in the GI tract, altering interstitial fluid and electrolytes
-increased bulk stimulates peristalsis and the absorbed water softens the stool
Bulk-forming laxatives can be used for
IBS and diverticulosis
Stool softeners
relieve constipation by reducing surface tension of the stool so water and lipids can enter the stool and soften the feces. This makes it easier to pass the stool.
Stool softeners are mostly used for
after surgery, or patients who should avoid straining
-softening of the stool usually takes 1 to 3 days after starting the drug
Lubricant laxatives
relieve constipation by creating a barrier between the feces and the colon wall that prevents the colon from reabsorbing fecal fluid, thus softening the stool. The lubricant also eases the passage of feces through the intestine
Lubricant laxatives are mostly used for
cases in which straining should be avoided, such as myocardial infarction, aneurysm, stroke, or hernia or after abdominal or rectal surgery
-they can help prevent pain and decrease the risk for tearing or laceration of hemorrhoids or anal fissures
Osmotic laxatives
also known as saline laxatives (includes lactulose and glycerin), relieve constipation by producing an osmotic effect by drawing water into the intestinal lumen of the small intestine and colon
-increase in fluid helps soften the stool and causes distention of the stool to help stimulate peristalsis
Osmotic laxatives are typically used for
cleansing of the bowels in preparation for certain surgical procedures, x-ray studies or colonoscopies
Lactulose can also be used for
patients with liver failure, because it helps reduce ammonia levels by nearly 50%
-help reduce confusion caused by liver failure
Laxatives may be used in conjunction with osmotic laxatives
as part of bowel preparation for surgery
Stimulant laxatives
increase peristalsis by several mechanisms: can stimulate sensitive nerve fibers in the intestine, irritate the mucosa in the intestine, and affect water and electrolyte secretion in the bowel
-peristalsis within 6 to 8 hours
Expected side effects of laxatives
nausea, abdominal cramps, bloating and diarrhea
Adverse effects of laxatives
inhaling the psyllium dust particles can cause hypersensitivity reactions, patients who do not drink enough water are at risk for esophageal obstruction, lubricant laxatives may produce decreased absorption of nutrients and fat-soluble vitamins, lipid pneumonia can occur by inhalation of fat-containing substances like mineral oil, osmotic laxatives can cause a fluid and electrolyte disturbance if overused, stimulant laxatives may cause muscle weakness, dermatitis, pruritius alkalosis, and electrolyte imbalance
Drug interactions with laxatives
may reduce absorption or bind to certain drugs because they can increase GI motility; separate loop diuretics, warfarin, salicylates and digoxin with laxatives by 2 hours; patients taking loop diuretics and digoxin are at risk of hypokalemia or hypernatremia
Anticholinergic drugs
dicyclomine (Bentyl)
reduce diarrhea and associated symptoms by selectively blocking the neurotransmitter acetylcholine from binding to its receptors in nerve cells. The nerve fibers of the parasympathetic system affect the involuntary movement of smooth muscle in the GI tract, lungs, and urinary tract
Antispasmodic drugs
atropine, hyoscyamine, phenobarbital, scopolamine (Donnatal)
these drugs reduce muscle contraction in the GI tract. This causes decreased muscle cramping, bloating, and diarrhea
Opioid agonist drugs
loperamide (Imodium), diphenoxylate with atropine (Lomotil)
these drugs are synthetic opioid agonists to decrease motility of the smooth muscle of the bowel. They are combined with atropine to decrease any mood-elevating effects of the opioid and reduce potential for abuse
Bulk-forming drugs
methylcellulose (Citrucel), psyllium (Fiberall, Karacil, Metamucil)
these act by absorbing fluids in the GI tract to form a mixture leading to softening and increased bulk of the stool. The increased bulk stimulates peristalsis leading to increased bowel mobility and more rapid transmit time through the GI tract. Stools are easier to pass. In addition, these drug can be helpful for patients with watery diarrhea by increasing the bulk and consistency of the stool`
Emollients/stool softener drugs
docusate (Colace, Sulfolax, Surfak)
these drugs lower the surface tension of the stool, allowing water and lipids to permeate the stool. This results in a softer, easier to pass stool. This typically takes 1 to 3 days for the patient to receive the benefit
Stimulant drugs
bisacodyl (Dulcolax, Doxidan, Feen-a-Mint)
these drugs stimulate peristalsis by irritating the mucosal lining of the intestine, and increase the amount of fluid in the intestine, relaxing the bowel and easing the passage of stool
Osmotic laxative drugs
polyethylene glycol (Miralax) these drugs cause increased absorption of fluid into the stool. As a result, the stool is softer and distends the colon, leading to peristalsis and easier passage of the stool
Nursing implications of anticholinergic drugs
do not give this drug within 2 hours of taking an antacid, do not stop this drug suddenly if the patient has used this drug for a long time, suddenly stopping the drug may result in withdrawal symptoms, to avoid local skin reaction with local pain and edema, inject this drug to a large muscle mass
Nursing implications of antispasmodic drugs
teach patients that they should not use contact lenses while taking these drugs because they can cause dry eyes and blurred vision, these drugs decrease GI motility and should not be used in infectious diarrhea, monitor patient’s vital signs carefully because these drugs can cause significant changes in heart rate, these drugs are not recommended in older adults because they can cause confusion and other adverse effects even at low doses
Nursing implications of opioid agonists
remind patients to avoid sedatives, tranquilizers, and opioid pain drugs because they may increase the risk for CNS effects, teach patients to follow directions carefully because overuse can result in constipation, drugs with atropine may cause side effects such as dry mouth or blurred vision. Use caution when taking the drug. Use ice chips or sugar-free candy to help keep lips and mouth moist
Nursing implications of bulk-forming drugs
teach patients that these drugs typically work within 12 hours to 3 days, instruct patients to drink at least one full glass of water with each dose to avoid blockages in the esophagus, these drugs can be mixed with water, fruit juices, or milk for better flavor
Nursing implications of emollients/stool softeners
teach patients that they may experience a change in urine color from pinkish red to yellow-brown depending on the alkalinity or acidity of the urine, teach the patient that these drugs typically have an effect in 1 to 3 days. They are not used to treat acute constipation but to prevent constipation from occuring
Nursing implications of stimulants
these drugs are available OTC and may be used for occasional constipation. Higher doses can be used as bowel preparation for x-rays of the colon or for colonoscopy, inform patients regarding the expected onset of action. Oral tablets can work 6-12 hours; rectal suppositories can work within 15 minutes to 1 hour
Nursing implications of osmotic laxatives
follow directions very carefully when these drugs are used as part of bowel preparation for colonoscopy or other procedures. Protocols may vary between prescribers. The goal is to have the best visibility of the lower intestine during examination. Instruct patients not to use these drugs more than recommended to avoid severe fluid and electrolyte imbalance. Some preparations include high amounts of sodium, so they should be avoided in patients who require a low sodium intake. These drugs work very quickly with onset of action within 1 to 3 hours. Make sure to teach patients that they should be near a place that has a bathroom or commode available
Anticholinergic drugs should not be given with
patients with a history of GI obstruction, benign prostatic hypertrophy, or glaucoma; some antispasmodic drugs contain phenobarbital, which should be avoided in patients with a history of sensitivity to barbituates; they should be avoided in patients with a history of substance abuse or alcoholism
