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Nursing 3703 Nursing 3703 Pharmacology Pharmacology Digestive System Digestive System Drugs Drugs By Linda Self APN, MSN, By Linda Self APN, MSN, CCRN CCRN

Nursing 3703 Pharmacology Digestive System Drugs

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Page 1: Nursing 3703 Pharmacology Digestive System Drugs

Nursing 3703Nursing 3703PharmacologyPharmacology

Digestive System DrugsDigestive System Drugs

By Linda Self APN, MSN, CCRNBy Linda Self APN, MSN, CCRN

Page 2: Nursing 3703 Pharmacology Digestive System Drugs

Effects of Drugs on the Digestive Effects of Drugs on the Digestive SystemSystem

Digestive system and drug therapy have a reciprocal Digestive system and drug therapy have a reciprocal relationshiprelationship

Some medications cause GI symptoms (e.g. EES); Some medications cause GI symptoms (e.g. EES); conversely, some GI disorders alter the absorption conversely, some GI disorders alter the absorption and metabolism of drugs (liver failure)and metabolism of drugs (liver failure)

Drugs affecting the GI tract include: laxatives, Drugs affecting the GI tract include: laxatives, antidiarrheals, antiemetics, drugs used in acid-peptic antidiarrheals, antiemetics, drugs used in acid-peptic disorders . Others include cholinergics (Aricept) disorders . Others include cholinergics (Aricept) anticholinergics (atropine), corticosteroids and anti-anticholinergics (atropine), corticosteroids and anti-infectives.infectives.

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Review physiology of the digestive systemReview physiology of the digestive systemOrgans and some associated disordersOrgans and some associated disorders Oral cavity-stomatitisOral cavity-stomatitis Esophagus-GERDEsophagus-GERD Stomach—peptic ulcers, gastritisStomach—peptic ulcers, gastritis Small intestine—malabsorption, Inflammatory bowel Small intestine—malabsorption, Inflammatory bowel Large intestine—diarrhea, constipationLarge intestine—diarrhea, constipation Pancreas—pancreatitis, Diabetes, ARDSPancreas—pancreatitis, Diabetes, ARDS Gallbladder—cholestasis,cholelithiasis, cholecystitisGallbladder—cholestasis,cholelithiasis, cholecystitis Liver—hepatitis, cirrhosisLiver—hepatitis, cirrhosis

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Cell protective mechanisms in Cell protective mechanisms in stomachstomach

Secretion of mucus and bicarbonateSecretion of mucus and bicarbonate Dilution of gastric acid by food and secretionsDilution of gastric acid by food and secretions Prevention of diffusion of HCL from the Prevention of diffusion of HCL from the

stomach lumen back into the gastric mucosal stomach lumen back into the gastric mucosal lininglining

Presence of prostaglandin EPresence of prostaglandin E Alkalinization of gastric secretions by Alkalinization of gastric secretions by

pancreatic juices and bilepancreatic juices and bile

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Cell Destructive Effects in StomachCell Destructive Effects in Stomach

Gastric acid, secreted by parietal cells Gastric acid, secreted by parietal cells Paretal cells contain receptrors for Paretal cells contain receptrors for

acetylcholine, gastrin and histamine, all of acetylcholine, gastrin and histamine, all of which stimulate gastric acid productionwhich stimulate gastric acid production

Acetylcholine is released by vagus nerve Acetylcholine is released by vagus nerve endings in response to stimuli, such as endings in response to stimuli, such as thinking about foodthinking about food

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Cell destructive effects cont.Cell destructive effects cont. Gastrin is a hormone released by the stomach Gastrin is a hormone released by the stomach

and duodenum in response to food ingestion. and duodenum in response to food ingestion. Affects parietal cells which in turn causes Affects parietal cells which in turn causes gastric acid to be released in stomach.gastric acid to be released in stomach.

Histamine is released from cells in the gastric Histamine is released from cells in the gastric mucosa and diffuses into nearby parietal cellsmucosa and diffuses into nearby parietal cells

Pepsin is a proteolytic enzyme that helps Pepsin is a proteolytic enzyme that helps digest protein foods and also can digest the digest protein foods and also can digest the stomach wallstomach wall

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Cell destructive effects Cell destructive effects

H. pyloriH. pylori is a gram negative bacterium found in is a gram negative bacterium found in the gastric mucosa of most clients with chronic the gastric mucosa of most clients with chronic gastritisgastritis

In 75% of those with gastric ulcers and in 90% In 75% of those with gastric ulcers and in 90% of clients with duodenal ulcersof clients with duodenal ulcers

Spread by oral fecal route or by iatrogenic Spread by oral fecal route or by iatrogenic spreadspread

Thought to affect mucosal functionThought to affect mucosal function

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Peptic Ulcer DiseasePeptic Ulcer Disease

Gastric UlcersGastric Ulcers Associated with stress, NSAIDs or Associated with stress, NSAIDs or H. pyloriH. pylori Manifested by painless bleeding Manifested by painless bleeding Take longer to heal than duodenal ulcersTake longer to heal than duodenal ulcers When associated w/stress, can occur at any ageWhen associated w/stress, can occur at any age With With H. pylori and H. pylori and NSAIDs generally are in NSAIDs generally are in

66thth or 7 or 7thth decade decade chronicchronic

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PUD cont.PUD cont.

Duodenal UlcersDuodenal Ulcers Can occur at any ageCan occur at any age Occur equally in men and womenOccur equally in men and women Manifested by abdominal painManifested by abdominal pain Associated with cigarette smokingAssociated with cigarette smoking Also associated with NSAIDs and Also associated with NSAIDs and H. pyloriH. pylori

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Peptic Ulcer and Acid Reflux Peptic Ulcer and Acid Reflux DisordersDisorders

Characterized by ulcer formation in the Characterized by ulcer formation in the esophagus, stomach or duodenumesophagus, stomach or duodenum

Occurs in areas that are exposed to gastric acid Occurs in areas that are exposed to gastric acid and pepsinand pepsin

Gastric and duodenal ulcers are more common Gastric and duodenal ulcers are more common than esophageal ulcersthan esophageal ulcers

Parietal cells contain receptors for Parietal cells contain receptors for acetylcholine—acetylcholine—implication of which is implication of which is stimulation by/of vagusstimulation by/of vagus

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Upper GI DisordersUpper GI Disorders Gastritis—acute or chronic inflammatory reaction of Gastritis—acute or chronic inflammatory reaction of

gastric mucosa.gastric mucosa.Usually will see peptic ulcers with gastritisUsually will see peptic ulcers with gastritis Non-steroidal anti-inflammatory Drug GastropathyNon-steroidal anti-inflammatory Drug Gastropathy Occurs with damage to mucosa by ASA or other Occurs with damage to mucosa by ASA or other

NSAIDsNSAIDsChronic ingestion causes irritation of the gastric Chronic ingestion causes irritation of the gastric

mucosa, inhibits the synthesis of prostaglandins mucosa, inhibits the synthesis of prostaglandins (which protect mucosal lining) and increasess the (which protect mucosal lining) and increasess the synthesis of leukotrienes and other substances that synthesis of leukotrienes and other substances that can cause mucosal damagecan cause mucosal damage

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Selected Upper Gastrointestinal Selected Upper Gastrointestinal DisordersDisorders

Review p. 853 in textReview p. 853 in text Include GastritisInclude Gastritis Nonsteroidal anti-Inflammatory Drug GastropathyNonsteroidal anti-Inflammatory Drug Gastropathy Stress UlcersStress Ulcers Zollinger-Ellison Syndrome-rare; excessive secretion Zollinger-Ellison Syndrome-rare; excessive secretion

of gastric acid and a high incidence of ulcers. Caused of gastric acid and a high incidence of ulcers. Caused by gastrin-secreting tumors in pancreas, stomach or by gastrin-secreting tumors in pancreas, stomach or duodenum. Often malignant.duodenum. Often malignant.

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Gastroesophageal Reflux DiseaseGastroesophageal Reflux Disease Most common disorder of the esophagusMost common disorder of the esophagus Characterized by regurgitation of gastric contents into Characterized by regurgitation of gastric contents into

the esophagus the esophagus Occurs most often after a mealOccurs most often after a meal Worse when recumbentWorse when recumbent Caused by incompetent lower esophageal sphincterCaused by incompetent lower esophageal sphincter Foods that cause relaxation include: etoh, caffeine, Foods that cause relaxation include: etoh, caffeine,

fats, chocolate, cigarrette smoking, gastric distention fats, chocolate, cigarrette smoking, gastric distention and medications (beta adrenergic blockers, calcium and medications (beta adrenergic blockers, calcium channel blockers, nitrates)channel blockers, nitrates)

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GERD cont.GERD cont. Occurs in men, women, and children Occurs in men, women, and children Common during pregnancyCommon during pregnancy More common after 40 years of ageMore common after 40 years of age

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Classifications and Individual DrugsClassifications and Individual Drugs

Antacids—alkaline substances that neutralize Antacids—alkaline substances that neutralize acids. Raising the pH to approximately 3.5 acids. Raising the pH to approximately 3.5 neutralizes more than 90% of gastric acid and neutralizes more than 90% of gastric acid and inhibits conversion of pepsinogen to pepsin. inhibits conversion of pepsinogen to pepsin. Commonly used antacids are aluminum, Commonly used antacids are aluminum, magnesium, and calcium compounds.magnesium, and calcium compounds.

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AntacidsAntacids Antacids vary in onset of active and dosage needed Antacids vary in onset of active and dosage needed

for neutralizationfor neutralization Aluminum compounds require large doses for Aluminum compounds require large doses for

effectiveness. They can cause constipation, effectiveness. They can cause constipation, hypophosphatemia and osteomalacia.hypophosphatemia and osteomalacia.

Magnesium based antacids have more rapid onset Magnesium based antacids have more rapid onset than Al++ but can cause diarrhea and than Al++ but can cause diarrhea and hypermagnesemiahypermagnesemia

Calcium compounds can cause hypercalcemia and Calcium compounds can cause hypercalcemia and hypersecretion of gastric acid==“rebound”hypersecretion of gastric acid==“rebound”

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AntacidsAntacids May be in combinations such as aluminum and May be in combinations such as aluminum and

magnesium hydroxidemagnesium hydroxide Decreases the diarrhea and constipationDecreases the diarrhea and constipation Most antacids are pregnancy category CMost antacids are pregnancy category C Antacids may be used in childrenAntacids may be used in children Antacides with magnesium are Antacides with magnesium are contraindicatedcontraindicated

because hypermagnesemia may resultbecause hypermagnesemia may result Additives such as simethicone may be addedAdditives such as simethicone may be added pills are as effective as liquidspills are as effective as liquids

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Use in Older AdultsUse in Older Adults Smaller doses as they secrete less acidSmaller doses as they secrete less acid May have some renal compromiseMay have some renal compromise Older adults often take large doses of NSAIDsOlder adults often take large doses of NSAIDs H2 receptor antagonists sometimes cause more H2 receptor antagonists sometimes cause more

side effectsside effects Sucralfate is well toleratedSucralfate is well tolerated PPIs are drugs of choice in this populationPPIs are drugs of choice in this population

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HelicobacterHelicobacter pyloripylori Requires combination of two antimicrobials and a Requires combination of two antimicrobials and a

PPI or an H2RAPPI or an H2RA Use amoxicillin, clarithromycin, metronidazole or Use amoxicillin, clarithromycin, metronidazole or

tetracycline for antibiotic portiontetracycline for antibiotic portion More than antimicrobial is indicated to prevent More than antimicrobial is indicated to prevent

resistanceresistance Bismuth compound is added for its antibacterial Bismuth compound is added for its antibacterial

effects as well as increasing the HCO3- and mucous effects as well as increasing the HCO3- and mucous contents of the stomachcontents of the stomach

Adding an H2RA or PPI decreases S/S and hastens Adding an H2RA or PPI decreases S/S and hastens healing healing

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Histamine 2 Receptor AntagonistsHistamine 2 Receptor Antagonists

Histamine release causes contraction of Histamine release causes contraction of smooth muscle in bronchi, GI tract, increases smooth muscle in bronchi, GI tract, increases permeability of capillaries,stimulation of permeability of capillaries,stimulation of sensory nerve endings sensory nerve endings and strong stimulation and strong stimulation of gastric acid secretionof gastric acid secretion

Vagal stimulation causes release of histamine Vagal stimulation causes release of histamine from cells in stomach, acts on receptors in from cells in stomach, acts on receptors in parietal cells>>>>increases HCL production.parietal cells>>>>increases HCL production.

Called H2 receptorsCalled H2 receptors

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Histamine 2 Receptor AntagonistsHistamine 2 Receptor Antagonists

Traditional antihistamines or H1 receptor Traditional antihistamines or H1 receptor antagonists generally reduce the effects of antagonists generally reduce the effects of histamine in the body but do not block histamine in the body but do not block histamine effects on gastric acid production.histamine effects on gastric acid production.

Replaced as first choice drugs by the PPIsReplaced as first choice drugs by the PPIs Prototype is cimetidinePrototype is cimetidine Generally are pregnancy category BGenerally are pregnancy category B May have multiple drug interactions and SEMay have multiple drug interactions and SE Available OTC and by RxAvailable OTC and by Rx

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H2RAH2RA Reduce dosage in pregnancyReduce dosage in pregnancy Cimetidine affects the cytochrome p450 drug Cimetidine affects the cytochrome p450 drug

metabolizing system in the liver; may cause metabolizing system in the liver; may cause confusion and antiadrogenic effects (gynecomastia)confusion and antiadrogenic effects (gynecomastia)

Ranitidine more powerfulRanitidine more powerful Use for up to 8 weeksUse for up to 8 weeks May be used long term but with variable dosingMay be used long term but with variable dosing Antacids may be given concurrently to relieve painAntacids may be given concurrently to relieve pain

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Proton Pump inhibitorsProton Pump inhibitors Strong inhibitors of gastric acid secretionStrong inhibitors of gastric acid secretion Bind irreversibly to the gastric proton pump to Bind irreversibly to the gastric proton pump to

prevent the release of gastric acid from parietal cellsprevent the release of gastric acid from parietal cells Suppresses acid secretion in response to all primary Suppresses acid secretion in response to all primary

stimuli including histamine, gastric, and acetylcholinestimuli including histamine, gastric, and acetylcholine Are the drugs of first choice in erosive esophagitis, Are the drugs of first choice in erosive esophagitis,

erosive gastritis and Zollinger-Ellisonerosive gastritis and Zollinger-Ellison

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PPIsPPIs More effective than H2RAMore effective than H2RA Faster symptom relief and faster healingFaster symptom relief and faster healing Used in prevention of esophagitisUsed in prevention of esophagitis Tx Tx H. pyloriH. pylori associated ulcers associated ulcers Side effects are nausea, diarrhea and HASide effects are nausea, diarrhea and HA Long term effects??? Implications??Long term effects??? Implications??

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ProstaglandinProstaglandin Naturally occurring prostaglandin E is Naturally occurring prostaglandin E is

produced by mucosal cells of the stomach and produced by mucosal cells of the stomach and duodenum. It inhibits gastric acid secretion duodenum. It inhibits gastric acid secretion and increases mucous and bicarbonate, and increases mucous and bicarbonate, mucosal blood flow and mucosal repair. With mucosal blood flow and mucosal repair. With inhibition of Prostaglandin E, erosion and inhibition of Prostaglandin E, erosion and ulceration of the gastric mucosa may occur. ulceration of the gastric mucosa may occur.

ImplicationsImplications

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Cytotec (misoprostol)Cytotec (misoprostol) Synthetic form of prostaglandin ESynthetic form of prostaglandin E Indicated for clients at high risk for GI Indicated for clients at high risk for GI

ulceration and bleeding and in those who take ulceration and bleeding and in those who take NSAIDsNSAIDs

Contraindicated in women of childbearing Contraindicated in women of childbearing ageage and during pregnancy (see text p. 862) and during pregnancy (see text p. 862)

May induce abortionMay induce abortion Side effects include diarrhea and abdominal Side effects include diarrhea and abdominal

crampingcramping

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SucralfateSucralfate Preparation of sulfated sucrose and aluminum Preparation of sulfated sucrose and aluminum

hydroxide that binds to normal and ulcerated mucosahydroxide that binds to normal and ulcerated mucosa Mechanism of action is unclearMechanism of action is unclear Thought to possible bind to the ulcer and form a Thought to possible bind to the ulcer and form a

protective barrier between the mucosa and gastric protective barrier between the mucosa and gastric acid, pepsin and bile salts; and stimulating acid, pepsin and bile salts; and stimulating prostaglandin synthesisprostaglandin synthesis

Effective in healing duodenal ulcers and in Effective in healing duodenal ulcers and in prevention of recurrenceprevention of recurrence

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SucralfateSucralfate Side effects include constipation and dry Side effects include constipation and dry

mouthmouth Must be given BidMust be given Bid Cannot be given with an antacid, H2RA or PPICannot be given with an antacid, H2RA or PPI May bind other drugs and prevent their May bind other drugs and prevent their

absorptionabsorption Give 2 hours before or after other drugsGive 2 hours before or after other drugs

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Effects of Acid Suppressant Drugs Effects of Acid Suppressant Drugs on Nutrientson Nutrients

Dietary folate, iron and Vitamin B12 are better Dietary folate, iron and Vitamin B12 are better absorbed from an acidic environmentabsorbed from an acidic environment

Less acidic environment can cause Less acidic environment can cause deficiencies of these nutrientsdeficiencies of these nutrients

Sucralfate interferes with the absorption of the Sucralfate interferes with the absorption of the fat soluble vitamins fat soluble vitamins

Magnesium containing antacids interfere with Magnesium containing antacids interfere with absorption of Vitamin Aabsorption of Vitamin A

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Nursing ActionsNursing Actions Review administration on p. 865-867Review administration on p. 865-867

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AntiemeticsAntiemetics Used to prevent or treat nausea and vomitingUsed to prevent or treat nausea and vomiting

Vomiting Vomiting is the expulsion of stomach contents is the expulsion of stomach contents through the mouththrough the mouth

Vomiting can occur w/o nauseaVomiting can occur w/o nausea

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Origin of vomitingOrigin of vomiting Vomiting center is located in medulla Vomiting center is located in medulla

oblongataoblongata Stimuli are relayed to the vomiting center from Stimuli are relayed to the vomiting center from

the periphery (gastric mucosa, peritoneum, the periphery (gastric mucosa, peritoneum, intestines, joints(?)) and centrally (from the intestines, joints(?)) and centrally (from the cerebral cortex; vestibular apparatus and from cerebral cortex; vestibular apparatus and from neurons in the fourth neurons in the fourth ventricle==chemoreceptor trigger zone) sitesventricle==chemoreceptor trigger zone) sites

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The vomiting center, chemoreceptor trigger zone and The vomiting center, chemoreceptor trigger zone and GI tract contain benzodiazepine, cholinergic, GI tract contain benzodiazepine, cholinergic, dopamine, histamine, opiate and serotonin receptors dopamine, histamine, opiate and serotonin receptors that are stimulated by emetogenic drugs and toxinsthat are stimulated by emetogenic drugs and toxins

For example: chemotherapy may stimulate the CTZ For example: chemotherapy may stimulate the CTZ which then signals the vomiting centerwhich then signals the vomiting center

Motion sickness—changes in body Motion sickness—changes in body motion>>stimulate receptors in inner motion>>stimulate receptors in inner ear>>transmitted to the CTZ and the vomiting centerear>>transmitted to the CTZ and the vomiting center

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Triggering the vomiting centerTriggering the vomiting center Efferent impulses cause glottic closureEfferent impulses cause glottic closure Contraction of abdominal muscles and Contraction of abdominal muscles and

diaphragmdiaphragm Relaxation of the GE sphincterRelaxation of the GE sphincter Reverse peristalsisReverse peristalsis Projection or expulsionProjection or expulsion

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Causes of nausea and vomitingCauses of nausea and vomiting PainPain Emotional disturbancesEmotional disturbances Radiation therapyRadiation therapy Motion sicknessMotion sickness Drug therapy: especially with alcohol, ASA, Drug therapy: especially with alcohol, ASA,

digoxin, anticancer drugs, antimicrobials, digoxin, anticancer drugs, antimicrobials, estrogen preparations and estrogen preparations and OpioidsOpioids

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Causes of Nausea and VomitingCauses of Nausea and Vomiting GI disorders such as inflammation of the GI GI disorders such as inflammation of the GI

tract, liver, gallbladder, pancreas, impaired GI tract, liver, gallbladder, pancreas, impaired GI motility and muscle tone (gastroparesis) and motility and muscle tone (gastroparesis) and ingestion of food that is irritating to the ingestion of food that is irritating to the mucosamucosa

Cardiovascular, infectious, neurologic or Cardiovascular, infectious, neurologic or metabolic disordersmetabolic disorders

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Antiemetic DrugsAntiemetic Drugs Most have anticholinergic, antidopaminergic, Most have anticholinergic, antidopaminergic,

antihistaminic or antiserotonergic effectsantihistaminic or antiserotonergic effects Generally are more effective in prophylaxis Generally are more effective in prophylaxis

than treatmentthan treatment Most act on the vomiting center, the Most act on the vomiting center, the

chemoreceptor trigger zone, the cerebral chemoreceptor trigger zone, the cerebral cortex, vestibular apparatus or any of the cortex, vestibular apparatus or any of the aboveabove

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Antiemetic DrugsAntiemetic Drugs

PhenothiazinesPhenothiazines—CNS depressants used in psychoses—CNS depressants used in psychoses Block dopamine from receptor sites in the brainBlock dopamine from receptor sites in the brain Act on CTZ and the vomiting centerAct on CTZ and the vomiting center Not all phenothiazines are anti-emeticsNot all phenothiazines are anti-emetics Cause drowsinessCause drowsiness Prochlorperazine (Compazine) and promethazine Prochlorperazine (Compazine) and promethazine

(Phenergan) are examples(Phenergan) are examples Some are pregnancy category B, others C, should Some are pregnancy category B, others C, should

check 1stcheck 1st

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Side effects continuedSide effects continued Extrapyramidal symptoms which include:Extrapyramidal symptoms which include:Dyskinesias (rhythmic movements), dystonias Dyskinesias (rhythmic movements), dystonias

(rhythmic jerks) and akathesia (inability to sit (rhythmic jerks) and akathesia (inability to sit still) related to dopamine receptor blockadestill) related to dopamine receptor blockade

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AntihistaminesAntihistamines Prevent histamine from exerting its Prevent histamine from exerting its

widespread effects on the bodywidespread effects on the body Classic antihistamines or H1 receptor blocking Classic antihistamines or H1 receptor blocking

agents are thought to block the action of agents are thought to block the action of acetylcholine in the brain (anticholinergic)acetylcholine in the brain (anticholinergic)

Indicated in Motion sicknessIndicated in Motion sickness Examples are Dramamine, hydroxyzine Examples are Dramamine, hydroxyzine

(Vistaril), meclizine (Antivert)(Vistaril), meclizine (Antivert)

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CorticosteroidsCorticosteroids May affect prostaglandin activity in the May affect prostaglandin activity in the

cerebral cortexcerebral cortex Dexamethasone and methyprednisolone are Dexamethasone and methyprednisolone are

commonly used in the management of commonly used in the management of chemotherapy induced emesis, usually in chemotherapy induced emesis, usually in combination with other anti-emeticscombination with other anti-emetics

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Benzodiazepine antianxiety Benzodiazepine antianxiety drugsdrugs

Not classic anti-emetics but often used in Not classic anti-emetics but often used in multidrug regimens to prevent nausea and multidrug regimens to prevent nausea and vomiting associated with cancer chemotherapyvomiting associated with cancer chemotherapy

Inhibit cerebral cortex input to the vomiting Inhibit cerebral cortex input to the vomiting centercenter

May give to those with anticipatory nausea May give to those with anticipatory nausea before chemotherapybefore chemotherapy

Example is Ativan (lorazepam)Example is Ativan (lorazepam)

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5 Hydroxytryptamine (5-HT3 or 5 Hydroxytryptamine (5-HT3 or Serotonin)Receptor AntagonistsSerotonin)Receptor Antagonists

Ondansetron, granisetron and dolasetron are Ondansetron, granisetron and dolasetron are used to prevent or treat moderate to severe used to prevent or treat moderate to severe nausea and vomiting r/t cancer chemotherapy, nausea and vomiting r/t cancer chemotherapy, radiation therapy and postoperativelyradiation therapy and postoperatively

Some anticancer drugs seem to affect a subset Some anticancer drugs seem to affect a subset of 5-HT3 recptors in the CTZ and the GI tractof 5-HT3 recptors in the CTZ and the GI tract

These drugs antagonize receptors both These drugs antagonize receptors both peripherally (GI) and in the CTZ to prevent peripherally (GI) and in the CTZ to prevent activationactivation

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5-HT3 receptor antagonists cont.5-HT3 receptor antagonists cont. Can be given IV or orallyCan be given IV or orally Side effects are mild to moderate and include: Side effects are mild to moderate and include:

diarrhea, headache, dizziness, constipation, diarrhea, headache, dizziness, constipation, muscle aches and transient liver enzymes muscle aches and transient liver enzymes elevationelevation

Ondansetron (Zofran) is the prototypeOndansetron (Zofran) is the prototype Metabolized by the liverMetabolized by the liver

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Miscellaneous AntiemeticsMiscellaneous Antiemetics Dronabinol (Marinol) is a cannabinoid used in Dronabinol (Marinol) is a cannabinoid used in

the management of nausea and vomiting the management of nausea and vomiting associated with anticancer drugs and associated with anticancer drugs and unrelieved by other drugs.unrelieved by other drugs.

Schedule III under federal narcotic lawsSchedule III under federal narcotic laws Withdrawal S/S may occurWithdrawal S/S may occur Sleep disturbancesSleep disturbances

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ReglanReglan Prokinetic that increases GI motility and the Prokinetic that increases GI motility and the

rate of gastric emptying by increasing the rate of gastric emptying by increasing the release of acetylcholine from nerve edings in release of acetylcholine from nerve edings in the GI tractthe GI tract

Can cause decreased n/v associated with Can cause decreased n/v associated with gastroparesisgastroparesis

Has central antiemetic effects, antagonizes the Has central antiemetic effects, antagonizes the action of dopamineaction of dopamine

Can be given IV, PO or IMCan be given IV, PO or IM

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Reglan continuedReglan continued Side effects include sedation, restlessness, and Side effects include sedation, restlessness, and

extrapyramidal reactionsextrapyramidal reactions May increase the effects of alcohol and May increase the effects of alcohol and

cyclosporine and decrease the effects of cyclosporine and decrease the effects of cimetidine and digoxin (decrease time for cimetidine and digoxin (decrease time for passage)passage)

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EmetrolEmetrol Phosphorated carbohydrate solutionPhosphorated carbohydrate solution Hyperosmolar solution with phosphoric acidHyperosmolar solution with phosphoric acid OTCOTC Felt to work by reducing smooth muscle Felt to work by reducing smooth muscle

contraction in the GI tractcontraction in the GI tract

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ScopolamineScopolamine Anticholinergic drugAnticholinergic drug Transdermal patchTransdermal patch Excellent for motion sicknessExcellent for motion sickness

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ContraindicationsContraindications When can delay or prevent diagnosisWhen can delay or prevent diagnosis When s/s of toxicity may be maskedWhen s/s of toxicity may be masked Reglan is relatively contraindicated in Reglan is relatively contraindicated in

Parkinson’s disease because it further dples Parkinson’s disease because it further dples dopaminedopamine

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Management ConsiderationsManagement Considerations 5-HT3 antagonists 15-HT3 antagonists 1stst choice in chemotherapy choice in chemotherapy

induced or postoperative N/Vinduced or postoperative N/V Drugs with anticholinergic and antihistaminic Drugs with anticholinergic and antihistaminic

properties are preferred for motion sicknessproperties are preferred for motion sickness If ambulatory, opt for drug that causes less If ambulatory, opt for drug that causes less

sedationsedation Phenergan is used for its antihistaminic, Phenergan is used for its antihistaminic,

antiemetic and sedative effectsantiemetic and sedative effects

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Management Considerations cont.Management Considerations cont.

Phenothiazines can have serious side effectsPhenothiazines can have serious side effects Reglan may be preferred for non-obstructive Reglan may be preferred for non-obstructive

gastric retentiongastric retention

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HerbalsHerbals Efficacy still debatableEfficacy still debatable

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Chemotherapy-induced Nausea and Chemotherapy-induced Nausea and VomitingVomiting

Chemo may be given during sleeping hoursChemo may be given during sleeping hours Decrease food intake few hours before TxDecrease food intake few hours before Tx Antiemetics should be given before the emetogenic Antiemetics should be given before the emetogenic

Tx and may be given for 2-3 daysTx and may be given for 2-3 days 5-HT2 receptor antagonists are drugs of choice for 5-HT2 receptor antagonists are drugs of choice for

this indicationthis indication Reglan is valid option but may need to give Reglan is valid option but may need to give

diphenhydramine to prevent the EPSdiphenhydramine to prevent the EPS Sometimes combo of steroid and 5-HT3 RA usefulSometimes combo of steroid and 5-HT3 RA useful

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Laxatives and CatharticsLaxatives and Cathartics

When stomach and duodenum are distended with When stomach and duodenum are distended with food, gastrocolic and duodenocolic reflexes are food, gastrocolic and duodenocolic reflexes are initiatedinitiated

The cerebral cortex controls the defecation reflex so The cerebral cortex controls the defecation reflex so that defecation can occur at acceptable times and that defecation can occur at acceptable times and placesplaces

In people who inhibit the defecation reflex or fail to In people who inhibit the defecation reflex or fail to respond to the urge to defecate, constipation developsrespond to the urge to defecate, constipation develops

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Laxatives are chemical substances that act to Laxatives are chemical substances that act to facilitate passage of bowel contentsfacilitate passage of bowel contents

Cathartics—a purgative action of the bowels, Cathartics—a purgative action of the bowels, action is stronger and generally produces action is stronger and generally produces elimination of liquid stoolselimination of liquid stools

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Indications for UseIndications for Use Reduce cholesterolReduce cholesterol Obtain stool sampleObtain stool sample Accelerate excretion of parasites after anthelminthics Accelerate excretion of parasites after anthelminthics

startedstarted Accelerate elimination of potentially toxic substances Accelerate elimination of potentially toxic substances

(Kayexalate)(Kayexalate) Pre-opPre-op Prevent straining at stool w/CAD, hemorrhoidsPrevent straining at stool w/CAD, hemorrhoids Relieve constipation in pregnancy, in the elderly; in Relieve constipation in pregnancy, in the elderly; in

children with megacolon, and in those w/decreased children with megacolon, and in those w/decreased motilitymotility

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Laxatives and cathatics should not be used in Laxatives and cathatics should not be used in the presence of undiagnosed abdominal painthe presence of undiagnosed abdominal pain

Could cause an inflamed organ to ruptureCould cause an inflamed organ to rupture Oral agents are contraindicated in intestinal Oral agents are contraindicated in intestinal

obstruction and fecal impactionobstruction and fecal impaction

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LaxativesLaxatives Bulk-forming laxatives—Citrucel, MetamucilBulk-forming laxatives—Citrucel, Metamucil Surfactant Laxatives—mainly prevent Surfactant Laxatives—mainly prevent

straining. They allow water to penetrate stool straining. They allow water to penetrate stool and act as detergent to facilitate admixing of and act as detergent to facilitate admixing of fat and water in the stool. Colace (docusate) or fat and water in the stool. Colace (docusate) or Surfak.Surfak.

Saline—magnesium citrate. Nulytely.Increase Saline—magnesium citrate. Nulytely.Increase osmotic pressure in intestinal lumen.Not safe osmotic pressure in intestinal lumen.Not safe for frequent use. Affect fluids and lytes. for frequent use. Affect fluids and lytes.

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CatharticsCathartics Stimulant type are the strongest and most Stimulant type are the strongest and most

abusedabused Cascara,bisacodyl, castor oil and senna Cascara,bisacodyl, castor oil and senna

productsproducts Mineral oil is a lubricant laxative. It slows Mineral oil is a lubricant laxative. It slows

colonic absorption of water.colonic absorption of water.

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OtherOther Lactulose—a disaccharide that is not absorbed from Lactulose—a disaccharide that is not absorbed from

the GI tract. Pulls water into intestinal lumen. Used to the GI tract. Pulls water into intestinal lumen. Used to treat constipation and hepatic encephalopathy. treat constipation and hepatic encephalopathy. Lactulose reduces production of ammonia in the Lactulose reduces production of ammonia in the intestine. Can affect lyte and water balance.intestine. Can affect lyte and water balance.

Sorbitol—monosaccharide that puls water into the Sorbitol—monosaccharide that puls water into the intestinal lumen and has laxative effects. It is given intestinal lumen and has laxative effects. It is given with Kayexalate (potassium removing resin to treat with Kayexalate (potassium removing resin to treat hyperkalemia).hyperkalemia).

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Laxative AbuseLaxative Abuse Public health problem in elderlyPublic health problem in elderly Use in patients with cancerUse in patients with cancer What is normal?What is normal? What are some measures to prevent What are some measures to prevent

constipation?constipation?

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Safety in UseSafety in Use Saline cathartics must be used cautiously in Saline cathartics must be used cautiously in

the renally impairedthe renally impaired Lactulose may be indicated in those with Lactulose may be indicated in those with

hepatic encephalopathy hepatic encephalopathy Seen frequently in form of enemas in Seen frequently in form of enemas in

hyperkalemia in hospitalhyperkalemia in hospital

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AntidiarrhealsAntidiarrheals Diarrhea is a symptom of numerous conditions Diarrhea is a symptom of numerous conditions

that increase bowel motility; cause secretion or that increase bowel motility; cause secretion or retention of fluids in the intestinal lumen and retention of fluids in the intestinal lumen and cause inflammation or irritation of the GI cause inflammation or irritation of the GI tract. End result: bowel contents are rapidly tract. End result: bowel contents are rapidly propelled and absorption of fluids and propelled and absorption of fluids and electrolytes is limite.delectrolytes is limite.d

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Causes of DiarrheaCauses of Diarrhea Abuse of laxativesAbuse of laxatives Intestinal infections—Intestinal infections—E. Coli 0157:H7 E. Coli 0157:H7 (can (can

result in a hemolytic uremic syndrome), result in a hemolytic uremic syndrome), Traveller’s diarrhea (Traveller’s diarrhea (E. coli), Campylobacter E. coli), Campylobacter jejuni, Salmonella, Shigella, jejuni, Salmonella, Shigella, rotatvirusrotatvirus

Inflammatory bowel diseasesInflammatory bowel diseases Drug therapy—Drug therapy—pseudomembranous colitis—pseudomembranous colitis—

Clostridium difficile (anaerobic, spore forming Clostridium difficile (anaerobic, spore forming rods)rods)

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AntidiarrhealsAntidiarrheals

Opiate related drugsOpiate related drugs ParegoricParegoric Defenoxin with atropine—MotofenDefenoxin with atropine—Motofen Diphenoxylate with atropine--LomotilDiphenoxylate with atropine--Lomotil

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AntibacterialsAntibacterials Azithromycin for Traveller’s diarrheaAzithromycin for Traveller’s diarrhea Cipro—E.coli, Camylobacter, ShigellaCipro—E.coli, Camylobacter, Shigella EES—amebiasisEES—amebiasis Flagyl—Clostridium difficileFlagyl—Clostridium difficile Bactrim-Traveller’s diarrheaBactrim-Traveller’s diarrhea Vancomycin—Clostridium difficile, even in Vancomycin—Clostridium difficile, even in

form of enemasform of enemas

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MiscellaneousMiscellaneous Questran—Crohns’. Binds and inactivates bile Questran—Crohns’. Binds and inactivates bile

salts in the intestine.salts in the intestine. Octreotide—diarrhea associated with HIV, Octreotide—diarrhea associated with HIV,

carcinoid tumors, cancer therapies or carcinoid tumors, cancer therapies or intractable diarrhea caused by other drugs.intractable diarrhea caused by other drugs.

Pancreatin—pancreatic enzymes used for Pancreatin—pancreatic enzymes used for replacement in patients w/deficiency of replacement in patients w/deficiency of pancreatic enzymespancreatic enzymes