Antiemetics

Question 1

what are antiemetics used for?

Answer 1

nausea/vomiting/motion sickness

Question 2

Nursing consideration in antiemetic use?

Answer 2

• VS, i/o, dehydration, fluid and electrolyte imbalance
• limit oral intake to clear fluids when n/v
• SE = drowsiness; protect client from injury

Question 3

Meclizine (Dramamine)

Functional Classification

Answer 3

Antiemetic, antihistamine, anticholinergic

Question 4

Meclizine (Dramamine)

Mechanism of Action

Answer 4

Acts centrally by blocking chemoreceptor trigger zone, which in turn acts on vomiting center

Question 5

Meclizine (Dramamine)

Uses

Answer 5

Vertigo, motion sickness

Question 6

Meclizine (Dramamine)

Nursing Considerations

Answer 6

ASSESS:

• VERTIGO/MOTION SICKNESS: nausea, vomiting after 1hr; assess vertigo periodically
• Signs of toxicity of other products, masking of symptoms of disease: brain tumor, intestinal obstruction
• Observe for drowsiness, dizziness, level of consciousness

Question 7

Metoclopramide (Reglan)

Functional Classification

Answer 7

Cholinergic, antiemetic

Question 8

Metoclopramide (Reglan)

Mechanism of Action

Answer 8

Enhances response to acetylcholine of tissue in upper GI tract, which causes the contraction of gastric muscle; relaxes pyloric, duodenal segments; increases peristalsis without stimulating secretions; blocks dopamine in chemoreceptor trigger zone of CNS

Question 9

Metoclopramide (Reglan)

Uses

Answer 9

Prevention of nausea, vomiting induced by chemotherapy, radiation, delayed gastric emptying, gastroesophageal reflux

Question 10

Metoclopramide (Reglan)

Side Effects

Answer 10

SUICIDAL IDEATION, SEIZURES, EPS, NEUROLEPTIC MALIGNANT SYNDROME; TARDIVE DYSKINESIA (>3MO, HIGH DOSES)

Question 11

Ondansetron (Zofran)

Functional Classification

Answer 11

Antiemetic

Question 12

Ondansetron (Zofran)

Mechanism of Action

Answer 12

Prevents nausea, vomiting by blocking serotonin peripherally, centrally, and in the small intestine

Question 13

Ondansetron (Zofran)

Uses

Answer 13

Prevention of nausea, vomiting associated with cancer chemotherapy, radiotherapy; prevention of postoperative nausea, vomiting

Question 14

Ondansetron (Zofran)

Side Effects

Answer 14

CNS: Headache, Dizziness, Drowsiness, Fatigue, EPS
GI: Diarrhea, Constipation, abdominal pain, dry mouth
MISC: rash, BRONCHOSPASM (rare), Musculoskeletal Pain, Wound Problems, Shivering, Fever, Hypoxia, Urinary Retention

Question 15

Ondansetron (Zofran)

Nursing Considerations

Answer 15

ASSESS:

• Absence of nausea, vomiting during chemotherapy
• Hypersensitivity reaction: rash, bronchospasm (rare)
• EPS: shuffling gait, tremors, grimacing, rigidity periodically

Question 16

Prochlorperazine

Functional Classification

Answer 16

Antiemetic, antipsychotic

Question 17

Prochlorperazine

Mechanism of Action

Answer 17

Decreases dopamine neurotransmission by increasing dopamine turnover through the blockade of the D2 somatodendritic autoreceptor in the mesolimbic system

Question 18

Prochlorperazine

Uses

Answer 18

Nausea, Vomiting, Psychotic Disorders

Question 19

Prochlorperazine

Contraindications

Answer 19

Hypersensitivity to phenothiazines, coma; infants, neonates, children <2yr; surgery

Question 20

Prochlorperazine

Side Effects

Answer 20

CNS: NEUROLEPTIC MALIGNANT SYNDROME, CV: CIRCULATORY FAILURE, TACHYCARDIA, HEMA: AGRANULOCYTOSIS

Question 21

Prochlorperazine

Nursing Considerations

Answer 21

ASSESS:

• EPS: abnormal movement, tardive dyskinesia, akathisia
• VS, BP; check patients with cardiac disease more often
• NEUROLEPTIC MALIGNANT SYNDROME: seizures, hypo/hypertension, fever, tachycardia, dyspnea, fatigue, muscle stiffness, loss of bladder control; notify prescriber immediately
• CBC, LFTs during course of treatment; blood dyscrasias, hepatotoxicity may occur
• Respiratory status before, during, after administration of emetic; check rate, rhythm, character; respiratory depression can occur rapidly among geriatric or debilitated patients