Chapter 34 Drugs Used to Treat Nausea and

Chapter 34 Drugs Used to Treat Nausea and Vomiting Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc.

Chapter 34 Lesson 34. 1 Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 2

Objectives • Compare the purposes of using antiemetic products • State therapeutic classes of antiemetics • Discuss scheduling of antiemetics for maximum benefit Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 3

Nausea and Vomiting • Nausea § Sensation of abdominal discomfort intermittently accompanied by a desire to vomit • Vomiting (emesis) § Forceful expulsion of gastric contents up the esophagus and out of the mouth • Regurgitation § Rising of gastric or esophageal contents to the pharynx as a result of stomach pressure Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 4

Common Causes of Nausea and Vomiting • Postoperative (PONV) • Motion sickness • Pregnancy § Morning sickness § Hyperemesis gravidarum • Psychogenic § Self-induced or involuntary vomiting in response to threatening or distasteful situations Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 5

of Nausea and Vomiting (cont’d) • Chemotherapy (CINV) § Anticipatory nausea and vomiting § Acute CINV § Delayed emesis • Radiation (RINV) § Associated with high-energy radiation, external source or implanted Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 6

Drug Therapy for Nausea and Vomiting PONV • Multimodal treatment approach • Hydration • Supplemental oxygen • Combination of antiemetics • Nonpharmacologic techniques prior to surgery • NG tube to prevent abdominal distention Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 7

Drug Therapy for Nausea and Vomiting (cont’d) • Motion sickness § Most medications chemically related to antihistamines, probably because of anticholinergic properties • Psychogenic vomiting § Diagnosis made after all other causes eliminated § Metoclopramide or antianxiety drug may be prescribed with counseling Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 8

Drug Therapy for Nausea and Vomiting (cont’d) • Pregnancy § Morning sickness controlled by diet § Antihistamines: diphenhydramine, dimenhydrinate, meclizine, cyclizine § Phenothiazines: promethazine, prochlorperazine § Ginger used in many cultures Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 9

Drug Therapy for Nausea and Vomiting (cont’d) • CINV § Combination of drugs used because emesis likely produced by more than one mechanism • Ondansetron (Zofran), dolasetron (Anzemet), granisetron (Kytril) • High doses of metoclopramide (Reglan); dexamethasone (Decadron, Hexadrol); lorazepam (Ativan), diphenhydramine (Benadryl, Diphenhist) • Haloperidol (Haldol) may be substituted for metoclopramide § Should be treated prophylactically Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 10

Drug Therapy for Nausea and Vomiting (cont’d) • Anticipatory nausea and vomiting § Progressive muscle relaxation, mind diversion, hypnosis, self-hypnosis, systematic desensitization • Delayed emesis § Combination of prochlorperazine, lorazepam, and diphenhydramine given orally 1 hour before meals • RINV § Granisetron, ondansetron, serotonin antagonists Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 11

Drug Class: Dopamine Antagonists • Drugs § Phenothiazines § Butyrophenones § Metoclopramide (Reglan) • Actions § Inhibit dopamine receptors that are part of the pathway to the vomiting center • Uses § Treat mild to moderate nausea and vomiting associated with anesthesia, surgery, radiation therapy, cancer chemotherapy Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 12

Drug Class: Serotonin Antagonists • Actions § Block the serotonin 5 -HT 3 receptors located in the chemoreceptor trigger zone of the medulla and in specialized cells of the GI tract • Uses § Treat nausea and vomiting associated with chemotherapy, radiation; PONV • Common adverse effects § Headache, diarrhea, constipation, sedation Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 13

Drug Class: Anticholinergic Agents • Actions § Counterbalance excessive amounts of acetylcholine thought to cause motion sickness • Uses § Treat motion sickness; nausea and vomiting associated with pregnancy • Common adverse effects § Anticholinergic effects, sedative effects Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 14

Drug Class: Corticosteroids • Drugs § Dexamethasone (Decadron, Hexadrol) § Methylprednisolone (Solu-Medrol, Depo-Medrol) • Actions § Mechanism of action unknown • Uses § In combination with other antiemetics to relieve nausea and vomiting; can also be used alone • Common and serious adverse effects § See Chapter 38 for further discussion Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 15

Drug Class: Benzodiazepines • Drugs: lorazepam (Ativan), diazepam (Valium) • Actions § Combination of effects – sedation, reduction in anxiety, possible depression of the vomiting center – and an amnesic effect • Uses § In combination with other antiemetics to treat vomiting and nausea, anxiety associated with chemotherapy • Common and serious adverse effects § See Chapter 16 for further discussion Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 16

Drug Class: Cannabinoids • Drugs § Dronabinol (Marinol) § Nabilone (Cesamet) • Actions § Several mechanisms inhibit pathways to the vomiting center • Uses § In patients refractory to other antiemetic regimens; only for patients receiving chemotherapy • Common adverse effects § Dysphoric effects Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 17

Drug Class: Neurokinin-1 Receptor Antagonists • Drugs § Aprepitant (Emend) § Fosaprepitant (Emenda) • Actions § Block effects of substance P, a neuropeptide in the CNS, responsible for vomiting • Uses § Prevent acute and delayed CINV • Common and serious adverse effects § Tiredness, nausea, hiccups, constipation, diarrhea, loss of appetite, headache, hair loss Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc. , an affiliate of Elsevier Inc. Slide 18