Chapter 33: Drugs Used to Treat Nausea and Vomiting

A patient is beginning the second round of high-dose cisplatin. Severe, chemotherapy-induced nausea and vomiting (CINV) occurred following the first treatment, requiring 72 hours of continuous IV hydration. In addition to her chemotherapy regimen, which medication would be best to administer?

a. Prochlorperazine (Compazine) suppository daily, on the day of treatment and the next 3 days

b. Anticholinergic agents, such as diphenhydramine or meclizine

c. Parenteral ondansetron 1 hour before chemotherapy, with oral ondansetron to continue for the next 4 days

d. Parenteral ondansetron during chemotherapy, with prochlorperazine suppositories daily for 1 week

ANS: C

With the patient's first treatment history and the emetogenic chemotherapy agent, cisplatin, ondansetron has shown to be the most effective for prevention of severe nausea and vomiting. Prochlorperazine and anticholinergic agents are not used for the treatment of CINV. The ondansetron should be administered 1 hour before the chemotherapy and continued for the next several days to prevent vomiting and dehydration associated with chemotherapy administration.

A patient expresses concerns about motion sickness. Which medication is most effective in preventing motion sickness?

a. Serotonin antagonists

b. Phenothiazines

c. Corticosteroids

d. Anticholinergics

ANS: D

Anticholinergic agents are used to treat motion sickness by counterbalancing the excessive amounts of acetylcholine present. Serotonin antagonists are used in the treatment of emesis associated with cancer chemotherapy, radiation therapy, and postoperative nausea and vomiting. Phenothiazines are used in the treatment of mild to moderate nausea and vomiting associated with anesthesia and surgery, radiation therapy, and cancer chemotherapy. Corticosteroids are used in the treatment of nausea and vomiting related to pregnancy, postsurgical state, chemotherapy, radiation, and bowel obstruction.

What is the purpose for the nurse administering metoclopramide (Reglan) IV postoperatively?

a. Prolong the effects of anesthesia.

b. Decrease the potential for thrombus formation.

c. Prevent postoperative nausea and vomiting.

d. Decrease postoperative pain.

ANS: C

Metoclopramide (Reglan) is an antiemetic and antagonist of dopamine and serotonin receptors. In addition to acting on receptor sites in the brain, metoclopramide increases sphincter tone in the gastrointestinal tract, which reduces nausea and vomiting. Metoclopramide does not affect anesthesia or the vascular system and does not have analgesic effects.

The nurse is assessing a patient with nausea and vomiting. Which additional autonomic symptoms that often accompany vomiting will the nurse observe?

a. Bradycardia, diarrhea, and flushing

b. Pallor, sweating, and tachycardia

c. Urinary urgency, chills, and dizziness

d. Fever, hyperventilation, and bradycardia

ANS: B

Autonomic symptoms of pallor, sweating, and tachycardia cause additional discomfort associated with vomiting. Bradycardia, diarrhea, flushing, urinary urgency, chills, dizziness, fever, and hyperventilation are not autonomic symptoms associated with vomiting.

The nurse would expect to administer which drug when treating hyperemesis gravidarum?

a. THC (Marinol)

b. Haloperidol (Haldol)

c. Dexamethasone (Prednisone)

d. Metoclopramide (Reglan)

ANS: D

Metoclopramide is the drug of choice when treating hyperemesis gravidarum because no teratogenic effects have been reported with the use of this drug. THC is used in the treatment of nausea and vomiting associated with cancer and cancer treatment. Haloperidol is used in the treatment of nausea associated with chemotherapy. Prednisone is used in the treatment of nausea associated with pregnancy, postsurgical state, chemotherapy, radiation, and bowel obstruction.

Why does the nurse monitor daily weights prior to the administration of antiemetic medications to chemotherapy patients?

a. Antiemetics are calculated according to body surface area.

b. Antiemetics are toxic, and the minimal dosage should be administered.

c. Weight loss is a common adverse effect associated with chemotherapy, and dosages may need to be readjusted.

d. Fluid overload is common, and antiemetic dosages are increased as treatment progresses.

ANS: C

Patients receiving chemotherapy are prone to weight loss resulting from nausea and vomiting. As with any drug therapy, the safe dosage per weight parameters should be assessed daily to avoid potential overmedication when patients are losing significant weight. Antiemetics are not calculated according to body surface area. Antiemetics are not toxic in recommended dosages. Fluid overload is unrelated to antiemetic therapy.

hat is an advantage of using benzodiazepines as an adjunctive treatment for nausea and vomiting associated with chemotherapy?

a. The long half-life will prolong the effectiveness of other drugs.

b. They increase a sense of euphoria.

c. The patient will not develop tolerance to the medications as quickly.

d. The antianxiety effect helps, in addition to reducing the frequency of nausea and vomiting.

ANS: D

Benzodiazepines (e.g., diazepam, lorazepam, midazolam) are effective in reducing not only the frequency of nausea and vomiting but also the anxiety often associated with chemotherapy. Benzodiazepines do not affect the effectiveness of other drugs. Although distraction can be an effective intervention, using benzodiazepines is not a method to achieve this goal. Tolerance to benzodiazepines can develop quickly; they do not affect the development of tolerance to other drugs.

What condition is occurring when a patient experiences nausea immediately on entering the clinic to receive another course of chemotherapy?

a. Psychogenic

b. Chemotherapy induced

c. Hyperemesis gravidarum

d. Anticipatory nausea and vomiting

ANS: D

Anticipatory nausea and vomiting is a conditioned response triggered by the sight or smell of the clinic or hospital or by the knowledge that treatment is imminent. Delayed reaction from a previous treatment would have occurred in a shorter interval after the other treatment. Delayed emesis occurs 24 to 120 hours after the administration of chemotherapy. Although smells can trigger nausea, this is not likely the cause of this patient's sickness. Hyperemesis gravidarum is excessive vomiting and nausea associated with pregnancy.

Which herb has been used in many cultures to provide relief of nausea associated with pregnancy?

a. Mint

b. Hyssop

c. Echinacea

d. Ginger

ANS: D

Ginger is an herb used in many cultures to treat pregnancy-induced nausea and vomiting. Mint is often used to treat mild dyspepsia. Hyssop is used as an expectorant and anticatarrhal. Echinacea is used to boost the immune system.

The nurse is caring for a 27-year-old patient taking a cannabinoid during chemotherapy. Which consideration will the nurse take into account?

a. Antihistamines may potentiate the effects.

b. Monitor the patient for fluid volume excess.

c. Previous use of marijuana requires increased dosage.

d. Inform the patient to avoid the intake of potassium.

ANS: A

Antihistamines, alcohol, analgesics, benzodiazepines, barbiturates, antidepressants, muscle relaxants, and sedative hypnotics increase toxic effects. Fluid volume excess is not an adverse effect of cannabinoids. Previous use does not necessarily require increased dosage. There are no dietary restrictions with the use of cannabinoids.

The recovery room nurse is preparing to assist with the care of several postoperative patients. Which patient would the nurse prioritize care for regarding the potential for postoperative nausea and vomiting (PONV)?

a. A 5-year-old child undergoing a closed reduction procedure with regional anesthesia

b. A 50-year-old woman undergoing a total hysterectomy with general anesthesia

c. A 27-year-old man undergoing a middle ear manipulation with general anesthesia

d. An 80-year-old man undergoing a total hip replacement with spinal anesthesia

ANS: B

Women have a higher incidence of PONV, possibly because of hormonal differences. Patients who have had general anesthesia have a higher incidence of PONV than those who have had regional anesthesia. Children ages 11 to 14 years have the highest incidence of PONV based on age-group. Spinal anesthesia is generally

The nurse is administering medications to various patients during morning medication pass. The patient at the lowest risk of having an adverse reaction is the patient receiving:

a. ondansetron.

b. scopolamine.

c. promethazine.

d. dexamethasone.

ANS: D

Dexamethasone is a corticosteroid. A particular advantage of the steroids, apart from their efficacy, is their relative lack of adverse effects. Ondansetron, scopolamine, and promethazine have more associated side effects than dexamethasone.