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

Slide 2 Chapter 34 Lesson 34.1 Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Slide 3 Objectives Compare the purposes of using antiemetic products State the 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 4 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 5 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 6 Common Causes 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.

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 Slide 7 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) 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 9 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 10 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 11 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 12 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 13 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 14 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 15 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 16 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 17 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 18 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.