Pharmacology : NURS

 Objective 1: list the components of gastric juice that contribute to the pain associated with peptic ulcers ◦ HCL, Pepsin, gastrin, lipase and histamine 2

 Chief cells ◦ Secrete pepsinogen  Parietal cells ◦ Stimulated by acetylcholine to produce HCL and gastrin ◦ Intrinsic factor  Mucous cells ◦ Coats stomach wall 3

 Objective 3: list drugs considered to be ulcerogenic  Smoking  NSAIDS  Corticosteroids  ASA 4

 Objective 4: explain the actions of the antiulcer drugs ◦ Decrease acidity ◦ Block histamine receptors ◦ Gastrointestinal prostaglandins 5

◦ Gastric acid pump inhibitors ◦ Coating agents ◦ Prokinetic agents ◦ Antispasmodic agents 6

 Raise the pH of gastric contents ◦ Higher pH, less acidity  Decreased pain 7

◦ Cheap ◦ Effective ◦ No constipation or diarrhea ◦ No systemic effects ◦ No rebound acidity 8

 Objective 7: differentiate between the various antacids 9

 Riopan, Maalox, Mylanta II, ◦ low sodium  Calcium carbonate, Aluminum hydroxide: constipation  Magnesium: ◦ diarrhea, electrolyte imbalance  Calcium carbonate & sodium bicarbonate: rebound acidity  Simethicone: ◦ defoaming agent Alginic acid: highly viscous solution— sodium alginate 10

 What are the assessments and interventions the nurse would do for a client taking an antacid? ◦ Renal ◦ GI ◦ Schedule of meds 11

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 Anticholinergics and antispasmodics the same ◦ Drugs include belladonna, probanthine, bentyl ◦ Used for spastic conditions of GI tract, peptic ulcers and irritable bowel syndrome ◦ Block parasympathetic nervous system  Activity is systemic  What would you see with anticholinergics? 13

◦ Which clients should not use anticholinergics? 14

 Assess: mental status, teach about orthostatic hypotension  In the elderly: increased constipation  If arrhythmia or palpitations: stop the drug, call the physician 15

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 H2 receptor antagonists ◦ Block histamine 2 receptors ◦ Raises pH of gastric contents  Used for GERD, duodenal ulcers, Zollinger-Ellison syndrome  Used to prevent or treat stress ulcers 17

 Drugs include ◦ Cimetidine (Tagamet) ◦ Famotidine (Pepcid) ◦ Nizatidine (Axid) ◦ Rantidine (Zantac)  Prototype 18

 Drugs can cause ◦ Dizziness, HA, diarrhea, constipation ◦ If confusion, disorientation, hallucination, see MD ◦ Can cause gynecomastia, hepatotoxicity 19

 Proton pump inhibitors ◦ Inhibit gastric acid pump ◦ Treat: severe esophagitis, GERD, gastric and duodenal ulcers, Zollinger-Ellison syndrome ◦ Can be used with antibiotics for H pylori ◦ S/E: diarrhea, HA, muscle pain and fatigue ◦ If rash: call MD 20

 Drugs include ◦ Esomeprazole (Nexium) ◦ Lansoprazole (Prevacid) ◦ Omeprazole (Prilosec)  prototype ◦ Pantoprazole (Protonix) ◦ Rabeprazole (Aciphex) 21

 Consult with MD  Avoid ETOH  Correct timing  No smoking  Immediately report blood 22

 Objective 13: identify causes of constipation  Objective 14: explain the uses of laxatives and cathartics  Objective 16: describe the actions of the types of laxatives  Objective 17: identify laxatives according to type 23

 Causes of constipation ◦ What are some things or conditions that can cause constipation? 24

 Act three ways ◦ Affect fecal consistency ◦ Increase fecal movement ◦ Remove stool from rectum 25

 Laxatives OTC; misused ◦ Dependence ◦ Damage bowel ◦ Cause problems in bowel 26

 Caution: surgical abdomen; appendicitis; N/V; fecal impaction; intestinal obstruction; undiagnosed abdominal pain  Contraindicated: hypersensitivity 27

 Bulk-forming  Emollient  Hyperosmotic  Saline  Stimulant 28

 Bulk-forming: natural fiber-like ◦ Absorb water ◦ Distends bowel ◦ Initiates reflex bowel activity  Best for long term use 29

 Emollient laxatives ◦ Stool softener (Docusate salts)  Lowers surface tension  Allows more fat & water to be absorbed  When should these be used? 30

◦ Lubricant laxative (mineral oil)  Lubricates fecal material & intestinal wall  Prevents H20 from leaking out of gut  Stool expands & softens 31

 The emollients and lubricants do not seem to increase peristalsis ◦ Oils a problem in constantly recumbent clients 32

 Hyperosmotic increase water content in large intestine ◦ Distends bowel ◦ Increases peristalsis ◦ Evacuates the bowel ◦ Non-absorbable ion exchange ◦ Used before diagnostic tests 33

 Saline laxatives increase osmotic pressure in small intestine ◦ Inhibit absorption of water & elytes ◦ Increase amount of water & elytes 34

 Results: watery stool  Increased distention of bowel  Promotes peristalsis & evacuation  Example: citrate of magnesia 35

 Stimulant laxatives stimulate nerves ◦ Increases peristalsis ◦ Increase fluid in colon  Increases bulk  Softens stool 36

 Few systemic effects ◦ Primary site of action the gut  Therapeutic Uses ◦ Common constipation ◦ Bowel preparation pre-op, diagnostic tests 37

 Bulk forming: impaction above strictures, fluid overload, electrolyte imbalance, gas  Emollient: skin rash, decreased absorption vitamins, lipid pneumonia, elyte imbalance  Hyperosmotic: abdominal bloating, rectal irritation, elyte imbalance 38

 Saline: magnesium toxicity, elyte imbalance, diarrhea, increased thirst  Stimulant: nutrient malabsorption, gastric irritation, elyte imbalance, discolored urine, rectal irritation 39

 Bulk-forming: interfere with absorption antibiotics, digoxin, salicylates, oral anticoagulants  Mineral oil: decrease absorption fat soluble vitamins  Hyperosmotic: increased CNS depression with barbiturates, general anesthetics, opioids, antipsychotics 40

 Oral antibiotics decrease effect of lactulose  Stimulants: decrease absorption antibiotics, digoxin, tetracycline, oral anticoagulants 41

 Objective 15: identify features of an ideal laxative and cathartic ◦ What do you think makes an ideal laxative? 42

 Assess: drugs client takes including OTC and herbs  Assess bowel elimination pattern  Assess diet and fluid intake  Assess activity and exercise  Assess for travel, dehydration  Assess for any past GI problems 43

 Objective 19: identify causes of diarrhea ◦ What things, conditions can cause diarrhea? 44

 Objective 20: describe the uses of antidiarrheal agents  Objective 21: identify the antidiarrheal agents 45

 Antidiarrheal drugs: local or systemic action ◦ Local: adsorb water to cause a formed stool ◦ Systemic: act on autonomic nervous system to decrease peristalsis 46

 Groups based on mechanism of action ◦ Adsorbents ◦ Antimotility ◦ Bacterial replacement ◦ Antisecretory ◦ Enzymes 47

 Treat underlying cause  Adsorbents: coat walls of GI tract; bind causative bacteria, toxin ◦ Bismuth subsalicylate (Pepto-Bismol) ◦ Attapulgite (Kaopectate) ◦ Aluminum hydroxide (AlternaGel, Maalox) ◦ Kaolin-pectin 48

 Decrease: peristalsis, muscle tone  Use with adsorbents, opiates  Examples: ◦ Atropine ◦ Hyoscyamine ◦ Hyosine 49

 Decrease bowel motility  Reduce pain  Increased absorption of water & elytes (absorption time) 50

 Adsorbents: bismuth subsalicylate: form of ASA  Activated charcoal  Side Effects ◦ Adsorbents: can increase bleeding time, dark stools, tinnitus, metallic taste, blue gums ◦ Anticholinergics: urinary retention, impotence, anxiety, brady or tachy-cardia, blurred vision, photophobia 51

 Adsorbents: decrease digoxin, clindamycin, oral hypoglycemics. Methotrexate-toxicity  Anticholinergics: decreased effect with antacids. Increased anticholinergic effect with tricyclic antidepressants, MAOIs, amantadine & antihistamines 52

 Opiates: additive CNS depression-alcohol, narcotics, sedative-hypnotics, antipsychotics, skeletal muscle relaxants  Pepto + oral anticoagulants 53

 Objective 22: describe the nursing implications associated with antidiarrheal agents 54

 Assess for cause of diarrhea ◦ Medications ◦ Infections ◦ Diet ◦ Lactulose intolerance ◦ Emotional stress ◦ Hyperthyroidism ◦ Inflammation of gut ◦ Surgical bypass of gut 55

 Objective 23: discuss the pathophysiology of nausea and vomiting ◦ Nausea: sensation of abdominal discomfort that is intermittently accompanied by the desire to vomit ◦ Vomiting: the forceful expulsion of gastric contents up the esophagus and out of the mouth 56

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◦ Dopamine antagonists ◦ Serotonin antagonists ◦ Anticholinergics ◦ Corticosteroids ◦ Benzodiazepines ◦ Cannaboinoids 58

 Objective 25: identify the mechanism of action, indications for use and desired effects of antiemetic drugs 59

 Phenothiazines, butyrophenones (Haldol) and metoclopramide (Reglan) ◦ Phenothiazines include Thorazine and Compazine  Drugs act to inhibit dopamine receptors that are part of the pathway to the vomiting center.  Also block other dopamine receptors in the brain  Can cause EPS 60

◦ Phenothiazines mostly used ◦ Reglan popular 61

 chemotherapy, radiation, post op  Block serotonin receptors in the CTZ and GI tract  Drugs include ◦ Dolasetron (Anzemet); granisetron (Kytril) and ondansetron (Zofran)  prototype 62

 counterbalance the amount of acetylcholine at the CTZ  Often for motion sickness; may see for clients on chemotherapy  Drug examples ◦ Cyclizene (Marezine), dimenhydrate (Dramamine), meclizene (Antivert), scopolamine 63

◦ Sometimes see Decadron ◦ Don’t know its action 64

◦ Active ingredient THC from marijuana ◦ Inhibit various pathways to the CTZ ◦ Drugs include: dronabenol (Marinol)  Do cause mind altering effects  Can be abused 65

 various activities such as sedation, depression of vomiting center, can cause amnesia ◦ Examples: diazepam, lorazepam and midazolam 66

 New for chemo clients ◦ Neurokinin receptor antagonist  Aprepitant (Emend) 67

 Emetics are used when the stomach needs to be emptied ◦ Use after overdose ◦ Example: syrup of Ipecac: NO LONGER used for kids  Fresh supplies are needed as the drug will expire 68

◦ What assessments would you make? ◦ What interventions would you initiate? 69