1	Antiemetics
2	Objectives After completing this chapter, the student should be able to: Define the term antiemetic Describe and list the indications, contraindications, and dosages for promethazine, dimenhydrinate, prochlorperazine, metoclopramide, droperidol, and trimethobenzamide
3	Gastrointestinal Medications
4	Promethazine Phenergan
5	Class Antihistamine and antiemetic
6	Description A phenothiazine derivative with potent antihistamine properties and anticholinergic properties
7	Mechanism of Action Possesses sedative, antihistamine, antiemetic, and anticholinergic properties Competitively blocks histamine receptors Unlike hydroxyzine, can be given IV Often administered with analgesics, particularly narcotics, to potentiate their effects
8	Pharmacokinetics Onset 5 minutes (IV), 20 minutes (IM) Peak effects Variable Duration 2-8 hours Half-life 10-14 hours
9	Indications Nausea and vomiting Motion sickness Sedation To potentiate effects of analgesics
10	Contraindications Patients in a comatose state and those who have received a large amount of depressants Hypersensitivity
11	Precautions May impair mental and physical abilities Should never be administered SC
12	Side Effects Drowsiness Sedation Blurred vision Tachycardia Bradycardia Dizziness
13	Interactions Depressant effect on CNS of narcotics, sedatives, or hypnotics; and alcohol is potentiated An increased incidence of EPS when administered to patients taking MAOIs
14	Dosage Nausea/vomiting 12.5-25 mg IV or IM Analgesics 25 mg
15	Prochlorperazine Compazine
16	Class Antiemetic
17	Description A phenothiazine derivative Highly effective in the treatment of severe nausea and vomiting
18	Mechanism of Action Does not prevent vertigo and motion sickness as do many of the other phenothiazines Blocks dopaminergic receptors in the brain Has weak anticholinergic properties
19	Pharmacokinetics Onset 10-20 minutes Peak effects Variable Duration 4-12 hours Half-life 24-48 hours
20	Indications Severe nausea and vomiting Acute psychosis
21	Contraindications Hypersensitivity Comatose patients or those who have received large amounts of CNS depressants
22	Precautions May impair mental and physical abilities Should never be administered SC because of local tissue irritation EPS appear to be higher than with many other phenothiazines Diphenhydramine should be available
23	Side Effects Drowsiness Sedation Blurred vision Tachycardia Bradycardia Dizziness Hypotension
24	Interactions Potentiates sedative effects of narcotics, sedatives or hypnotics, and alcohol
25	Dosage 5-10 mg IM or IV IV route preferred with severe nausea and vomiting because onset of action is much more rapid Often, 10 mg is placed in 1 mL of LR or NS and administered.
26	Other Common Antiemetics
27	Metoclopramide Reglan
28	Dosage 10-20 mg IM Severe intractable nausea and vomiting 10 mg slow IV over 1-2 minutes 10 mg diluted in 50 mL of NS and administered over 15 minutes IV is preferred route in severe nausea and vomiting due to rapid onset of action
29	Droperidol Inapsine
30	Dosage 2.5-10 mg IV or IM
31	Trimethobenzamide Tigan
32	Dosage 200 mg IM Should not be administered IV
33	Zofran Ondansetron HCl
34	Dosage 4 – 8mg PO tabs 4mg/5mL PO oral solution 4mg Slow IV Push 0.15mg/kg Slow IV Push for children
35	Questions???