PHARM: GI Meds

Mechanism

Anti-emetic and Anti Nausea ______ of Action:

Each work by blocking a different pathway to vomitting in the brain

GI Tract

__ _____: SoA for Prokinetics and Serotonin blockers

Inner Ear

_______ ___: Labyrinth. SoA for Anticholergenics, Antihistamines, Neuroleptics, and Prokinetics

Cerebral Cortex

______ _____ SoA for THC, Corticosteroids, Serotonin blockers

Anticholergenics

Antiemetic class ___________:

MoA: Blocks Ach receptors in vestibular nuclei and reticular formation 

• Prevents nauseous stimuli from being transmitted from inner ear to CTZ

• Drys out GI secretions and reduces SM spasm 

Indications: Motion sickness, N&V, secretion reduction pre-op or EOL. 

AE’s: Drying effects. 

Contraindications: Narrow angle glaucoma. Increases IOP. 

Eg: Scopolamine

Antihistamines

Class of Antiemitics: __________

MoA: Binds to and blocks histamine receptors. Prevents cholergenic stimulation at vestibular and reticular sysyems 

• Inhibits Ach

• Also has antisecretory and antispasmodic effects 

Indications: Motion sickness and N&V. Very commonly used in uncomplicated N&V'

AE’s: Anticholergenic (Drying) effects 

Eg: Dimenhydrinate (Gravol) 

Antidopaminergic

Anti emetic class __________ Drugs:

MoA: Blocks dopamine receptors in CTZ

• May have Anticholergenic properties to block Ach and calm CNS

Indications: Complicated N&V

AE’s: Tachycardia, pseudoparkinsonian symptoms, extrapyramidials

Eg: Prochlorperazine (Stemetil)

Mostly used as an antipsychotic but also antiemetic. Used when antihistamines dont work.

Prokinetic

Anti-emitic class: _______ Drugs

MoA: Blocks dopamine in CTZ. Desensitizing it.

• Stimulates Ach in GI tract to increase peristalsis and promote gastric emptying

Indications: Delayed gastric emptying, GERD, cancer associated nausea, post op N&V

AE’s: EPS, Long term use associated with tarditive dyskinesia 

Contras: GI obstruction due to increased peristalsis

Nursing consideration: Given at least 30 mins before meals and at bedtime 

Serotonin

Antiemetic class _______ blockers:

MoA: Blocks 5-HT3 receptors located in GI tract, CTZ, and vomiting centre

Indications: Cancer therapy, post op N&V, 

NC’s: Given 30 mins before start of chemo 

eg: Ondensetran (Zofran) 

THC

Antiemetic class: ____ agents

MoA: Inhibitor effect on certain areas in brain (reticular, thalamus, cerebral cortex)

• Alters mood and body perception of its surroundings. Helps to relieve N&V

Indications: Cancer therapy, anorexia associated with weight loss r/t HIV or cancer. 

AE’s: Euphoria, drowsiness, anxiety, dry mout

Anti-emetic

_____ ______ Nursing considerations:

• Should not be taken with alcohol or other CNS depressants 

Ginger

Anti emetic herbal product ______:

Indications: N&V

Interactions: May increase absorbtion of all oral meds. Increased bleeding risk with anticoagulants and antiplatelets

Anti Diarrheal

____ _____ agents: Used to treat stools that are

• Increased in frequency

• Increased in liquidity

• Increased in weight

Adsorbents

Anti diarrheal class ______:

MoA: Coats GI tract, binds to causitive bacteria or toxin, and eliminates through stool 

AE’S: Increased bleeding time, constipation, dark stools, confusion, twitching, hearing loss, tinnitus, metallic taste

Ints: Many! Affects GI absorption, less available surface area.

Ex: Bismuth Subsalicylate (Pepto) 

Anticholergenics

Anti diarrheal class _______: Also anti emetic class

MoA: Slows peristalsis by reducing rhythmic contractions of smooth muscle and tone of GI tract. Decreases secretions

AE’s: Urinary retention or hesitancy, impotence, headache, dizziness, confusion, anxiety.

Ex: Atropine, Hycosamine

Probiotics

Anti diarrheal class ________:

MoA: Re-establishing normal intenstinal flora. Commonly used post abx ‘

No listed AE’s

Eg: Lactobacillius (Lacidofil)

Opiates

Anti diarrheal class ______ and ____ related agents:

MoA: Decreases bowel motility, increases transit time, and relieves rectal spasms

Indicated only in situations of severe diarrhea 

AE’s: Drowsiness, sedation, dizzines, lethargy, resp depression 

Eg: Loperamide (Immodium), codiene

Constipation

________: abnormally infrequent or difficult passage of feces through lower GI tract. Disorder of movement through colon or rectum 

• Non pharm management used first: Dietary and behaviour

• Massive abuse potential with pharm treatment

Laxatives

_____: Class of meds used to treat constipation

Moa: One of three

1. Affect fecal consistency

2. Increases fecal movement through colon 

3. Facilitate defecation through rectum 

Bulk forming

_____ _____ laxatives:

MoA: Absorb water into intestines. Increasing bulk and descending in bowel 

• Do not generally cause dependency. Can be used long term 

• Action limited to GI tract

Eg: Psycillium (Metamucil)

Emollient

______ laxatives (AKA stool softeners)

MoA: Lower surface tension of GI fluids, resulting in more water and fat being absorbed in stool and intestines 

Lubricant _______: Work by lubricating fecal material and intestional wall. Preventing water absorbtion.

Eg: Mineral oil 

Hyperosmotic

_______ laxatives:

MoA: Increases fecal water content. Resulting in increased distenstion, peristalsis, and evacuation 

SoA: Limited to large intestine

Eg: Lactulose, PEglyte

Lactulose

Sample hyperosmotic laxative_______:

• Draws water into bowel

• Reduces blood ammonia by converting ammonia to ammonium 

• Hepatic encephalopathy: Ammonium trapped in intenstine and cannot return to circulation. MoA excretes ammonium

Saline

______ Laxatives:

MoA: Increases osmotic pressure in small intestine by inhibiting water absorbtion

• Increases distenstion, peristalsis, and evacuation 

• Can cause watery stools 

• Often used in bowel prep

Eg: Milk of magnesia

• Contraindicated in renal failure 

• Used in many combo products: Diovol, Pepcid 

Stimulant

______ laxatives: MOST LIKELY TO CAUSE DEPENDENCE

MoA: Stimulate nerves that innervate intestines. Results in increased peristalsis. Can cause abd pain 

• Also increases fluid in colon to increase bulk and soften stool 

• Avoid other meds within one hour of taking 

• Eg: sennacot.

• Ind’s: Used for relief of acute constipation or bowel prep. Common OTC laxative

• May discolour urine and cause abd pain 

Laxatives

Nursing Implications for: ______

• Not for use for abd pain, cramps, nausea, or GI diseases. 

• Do not crush stimulants

• Bulk formings and emollients taken with at least one full glass of water 

• Long term use can lead to dependence 

• ALL laxatives can cause F&E imbalance 

H. Pylori

GI disease: Treated with 3-4x therapy.

• 7-14 day course of PPI 

• Abx: Clarithromyocin, Amox, or metranidazole 

GERD

Disease: ______

• Inflammation of intestional sphincter caused by reflux of gastric acid into esophagus 

• Main cause: Incompetent lower esophageal sphincter

• Non-pharm interventions: No smoking, BW loss, raise HOB

Antacids

GI Med Class _______:

MoA: Neutralize gastric acidity, increase secretion of mucous bicarbonate ions and prostaglandins

Ind’s: Peptic ulcer disease, GERD

Common availabilites: Aluminum, Calcium, Mg, Na

Eg: Almagel 

• Interactions: Increase of stomach PH affects absorption. increases absorption of basic drugs and decreased absorption of acidic drugs

Histamine 2

Antacid class: ______ _ Blockers (antagonists):

MoA: Blocks H2 receptors in parietal cells of stomach.

• Suppresses secretion of gastric acid by blocking H2 receptors 

• - Does not fully eliminate HCl

Implications: Assess for allergies, liver function

Teaching: 1hr before or after antacids

Cimetidine: Binds to cytochrome p450 enzyme- absorbtion impacts

Protein Pump

Antacid class: _______ ______ Inhibitors:

MoA: IRREVERSIBLY binds to H+/K+ ATPase pump mechanism. Prevents movement of acidic H+ ions from parietal cells into stomach

• Results in achlorydria: Complete HCl absence in stomach

• - Prazole: Lansoprazole (Prevaid) 

Inds: GERD, short term treatment of duodenal and benign gastic ulcers 

AE’s: Long term use gives C-Diff predisposition 

Pepsin

Antacid class:______ Inhibitor

MoA: Promotes ulcer healing by creating protective barrier and limiting pepsin action. Has little absorption from gut into blood

• May delay PPI absorption

• AE: Constipation, nausea, dry mouth

Prostaglandin E

_________ _ Analogue: Acid controlling drug

MoA: Antiulcer agent. Prevents NSAID related ulcers 

• Misoprotil : DO NOT USE IN PREGNANCY

• Therapeutic doses for duodenal ulcers cause cramping and pain

Cholergenic

_________ drugs: Urinary agents: PO med used in treatment of acute postop and postpartum non-obstructive urinary retention 

MoA: Mimics ACh action (cholergenic agonist)→ relaxes sphincter of urinary bladder and Gi tract to allow for emptying

AE’s:

Salivation

Lacrimation

Urinary Incontience 

Diarrhea

GI Cramps 

Emesis