Pharmacology Antiemetic Agents
When considering the tendency of antiemetic agents to cross the placenta, which assessment question should the nurse initially ask every childbearing aged woman before initiating the therapy?
"Are you pregnant?" -Assess for possible contraindications or cautions that include the current status of pregnancy and lactation because of the potential for adverse effects on the fetus or nursing baby.
A nurse is caring for a client admitted to the unit for nausea and vomiting who was treated with ondansteron. A friend visiting the client asks the nurse why the client is sleeping. Which is the nurse's best response?
"The medication makes the client sleepy by blocking the action of the serotonin receptors." -Ondansteron is a serontonin receptor antagonist and works by antagonizing serotonin receptors, preventing their activation by the emetogenic drugs and toxins. The nurse's best response is telling the friend that the medication blocks the action of the serotonin receptors.
A client is to start receiving chemotherapy at 10:00 AM. The client has an order for intravenous metoclopramide. The nurse would expect to give the drug at which time?
9:30 AM -Metoclopramide is given intravenously 30 minutes before chemotherapy.
Which client would benefit from administration of an emetic medication?
A 25 year old who has ingested bacterial infested fruit -An emetic is an agent used to induce vomiting to rid the stomach of toxins or drugs.
When considering the central nervous system (CNS) effects presented by an antiemetic agent, which client presents a contraindication for their use?
A client recently started on hypertensive medication therapy -Assess for possible contraindications or cautions that include hypotension or hypertension, which could be affected by the CNS effects of the drug.
Which would the nurse anticipate to be used for the prevention of nausea from motion sickness?
Scopolamine (Transderm Scop) -Scopolamine is an anticholinergic medication and is most commonly used to treat or prevent motion sickness.
Metoclopramide is classified as a nonphenothiazine antiemetic.
True -The only nonphenothiazine currently available for use as an antiemetic is metoclopramide.
What are the most common adverse effects associated with drug therapy?
nausea and vomiting
When teaching a group of recent nursing graduates about the clinical use of promethazine, a nursing educator should emphasize that this drug is absolutely contraindicated in which client population?
Children under the age of two -A black box warning alerts nurses that promethazine is contraindicated in children younger than 2 years of age because of the risk of potentially fatal respiratory depression.
The nurse is caring for a client with liver disease who is receiving promethazine for nausea. What adverse effect may occur in this client?
Cholestatic jaundice -Cholestatic jaundice is jaundice caused by thickened bile or bile plugs in the small biliary passages of the liver.
An adult client being administered hydroxyzine for nausea should be monitored for which adverse effect?
Dry mouth -Anticholinergic effects, including dry mouth, can result from the use of hydroxyzine.
Which assessment datum serves to contraindicate the use of an antiemetic agent?
History of chronic liver dysfunction -Assess for possible contraindications or cautions include a history of impaired hepatic function, which could interfere with the excretion of the drug.
Which part of the brain is responsible for autonomic functioning such as ventilation, cardiac conduction, and vomiting?
Medulla Oblongata -The medulla oblongata is the vomiting center as well as the center for other autonomic functioning. It is located in the hindbrain.
A hospitalized toddler has been prescribed an antiemetic. The nurse will implement which intervention based on the child's unique needs?
Monitoring for electrolyte imbalances -Antiemetics should be used with caution in children who are at higher risk for adverse effects, including CNS effects, as well as fluid and electrolyte disturbances.
Different medications are used to treat the differing causes of nausea and vomiting. Phenothiazines, although effective against many causes, are usually ineffective in the treatment of nausea and vomiting created by:
Motion Sickness -Phenothiazines are usually effective in preventing or treating nausea and vomiting induced by drugs, radiation therapy, surgery, and most other stimuli, but are usually ineffective in motion sickness.
Which would an instructor include as an example of a phenothiazine used as an antiemetic?
Perphenazine -Perphenazine is a phenothiazine antiemetic.
Ondansetron (Zofran) belongs to which pharmacological category of medications?
Selective 5-HT3 receptor antagonist
The nurse is discussing the possible side effects of chemotherapy with a client. What information obtained during the client's admission assessment and interview will have a direct influence on the management of nausea and vomiting?
The client has been prescribed phenothiazine for anxiety -Phenothiazine is antianxiety drug that blocks the responsiveness of the CTZ to stimuli, leading to a decrease in nausea and vomiting.
In which of the following scenarios would the nurse question the order for ondansetron (Zofran)?
Treatment of gastroesophageal reflux -Because the mechanism of action of ondansetron (Zofran) does not act directly on the gastrointestinal system as other antiemetics do, the nurse should question this order as a treatment for gastroesophageal reflux.
A client, prescribed an antihistamine for nausea, should be monitored for which adverse effect of this classification of medication?
Urinary retention -Adverse anticholinergic effects of antihistamines are dizziness, confusion, dry mouth, and urinary retention.
The nurse is caring for a male client who has benign prostatic hypertrophy. The nurse would be alert for what complication if this client is given promethazine for treatment of nausea?
Urinary retention -Promethazine may cause urinary retention, which may be problematic in a client who already has benign prostatic hypertrophy.
A male client has been receiving promethazine for nausea that occurred following chemotherapy. Recently it has been discovered that this client has developed liver dysfunction. The nurse anticipates that the health care provider will do what to treat this client's nausea?
Use an alternative medication -Phenothiazines are metabolized in the liver and eliminated in urine. In the presence of liver disease (e.g., cirrhosis, hepatitis), metabolism may be slowed and drug elimination half-lives prolonged, with resultant accumulation and increased risk of adverse effects.
Which statement indicates that the client has understood the teaching provided on hydroxyzine?
"I may experience drowsiness with this medication." -Hydroxyzine will produce drowsiness in the client.
A female patient has been administered metoclopramide (Reglan) for nausea. Which statements indicates that she has understood the teaching provided by the nurse?
"I may experience drowsiness with this medication." -Metoclopramide will produce drowsiness in the patient.
A nurse is preparing to administer hydroxyzine to the nauseated client. Which is included in the teaching plan about the medication?
"This medication will help with the nausea by making you drowsy." -Hydroxyzine works by blocking the action of acetylecholine in the brain, which relieves the nausea and vomiting and causes the client to feel less nauseated and sleepy.
Which nonpharmacologic interventions should the nurse teach the client who is currently reporting nausea and vomiting? Select all that apply.
-Acupuncture -Acupressure wrist bands -Use of herbal supplements -Nonpharmacologic interventions include acupuncture and acupressure.Use of herbal supplements is also a nonpharmacologic intervention.
What would increase the risk of sedation in a patient receiving meclizine? (Select all that apply.)
-Diazepam -Codeine -Alcohol -Hydrocodone -A patient receiving meclizine has an increased risk of sedation if the patient combines the drug with alcohol, or other drugs that cause CNS depression such as diazepam, codeine, or hydrocodone.
The home care nurse is visiting a client who is receiving antiemetics. Which actions will the nurse perform to ensure safe and effective treatment for the client? (Select all that apply.)
-Reinforce teaching about dosage -Encourage client to sip on clear fluids to prevent dehydration -Do not drive while taking antinausea medicine
Which client is a candidate for cannabis therapy? Select all that apply.
-The 16 year old with medication resistant cancer pain -The 55 year old with AIDS related anorexia -A 78 year old diagnosed with terminal brain cancer -The U.S. Food and Drug Administration has approved the use of the active ingredient in cannabis, delta-9-tetrahydrocannabinol, in an oral form for the relief of nausea and vomiting in cancer patients who have not responded to other therapies and for the treatment of anorexia associated with AIDS.
What consideration should be stressed when educating a client on a new prescription for aprepitant? Select all that apply.
-the potential for significant drug interactions -the possibility of dizziness as an adverse effect -the drug's effect on oral contraception effectiveness -Aprepitant produces significant interactions that alter the effectiveness of other medications.Aprepitant is well tolerated, with the most common adverse effects being fatigue, weakness, dizziness, abnormal heart rhythm, headache, and hiccups. The drug reduces the effectiveness of oral contraceptives for up to 28 days after administration
A patient receives prochlorperazine by IM injection. The nurse would expect the drug to begin acting within which time frame?
10 to 20 minutes -Prochlorperazine, when given by IM injection, has an onset of action of 10 to 20 minutes.
The order for the patient reads: ondansetron (Zofran) 2 mg IV now. The vial of Zofran on the floor contains 4mg/5mL. How many mL should be administered?
2.5 mL
A client is undergoing a course of radiotherapy for the treatment of leukemia. Treatments in the past have caused the client severe nausea and vomiting. The oncology nurse should normally administer antiemetics on what schedule?
30-60 minutes prior to treatment -The nurse should normally administer antiemetic drugs 30 to 60 minutes before a nausea-producing event, when possible.
All of the following are centrally acting antiemetics EXCEPT
Adsorbents -Adsorbents act locally by binding to digestive mucus.
A client is receiving a phenothiazine antiemetic. The nurse instructs the client to use the call light if he needs to get out of bed to go to the bathroom based on the understanding that this group of drugs is associated with:
Central nervous system (CNS) effects -CNS effects, especially dizziness and drowsiness, are associated with phenothiazines and necessitate safety measures such as assistance with ambulation.
When reviewing a newly admitted client's previous medication record, the nurse notes that the client has previously been treated with aprepitant. The nurse is justified in suspecting that this client's medical history includes which therapy/treatment?
Chemotherapy -Prescribers often order aprepitant as part of combination therapy along with a 5-HT3 receptor antagonist and corticosteroids to treat both acute and delayed nausea and vomiting associated with chemotherapy.
A client who is undergoing cancer treatment is being discharged home with a prescription for ondansetron. When providing medication education concerning ondansetron, the nurse should describe actions that the client can take to address what common adverse effect?
Diarrhea -Diarrhea is a common adverse effect of ondansetron; therefore, the nurse also needs to assist clients and caregivers with appropriate use of the drugs and other interventions to prevent fluid and electrolyte depletion.
A client diagnosed with Parkinson's disease develops nausea and vomiting. Promethazine may be contraindicated because it depletes levels of what neurotransmitter?
Dopamine -Promethazine and other phenothiazines have widespread effects on the body. The therapeutic effects in nausea and vomiting are attributed to their ability to block dopamine from receptor sites in the brain and chemoreceptor trigger zone (CTZ). This blockage of dopamine has the potential to exacerbate parkinsonian effects.
A female client is receiving chemotherapy to treat her cancer. Several antiemetics have been prescribed, and each has been unsuccessful in treating her nausea and vomiting. The health care provider chooses to prescribe what cannabinoid drug to manage her symptoms?
Dronabinol -Dronabinol is a cannabinoid used in the management of nausea and vomiting associated with chemotherapy unrelieved by other antiemetic drugs. It is a Schedule III drug under federal narcotic laws.
The nurse is caring for a 19-month-old child who has been hospitalized with dehydration secondary to nausea and vomiting. The nurse is aware that promethazine will not be used for this client because it can cause what in children under the age of 2?
Fatal respiratory depression -A black box warning alerts nurses that promethazine is contraindicated in children younger than 2 years of age because of the risk of potentially fatal respiratory depression.
Which nonpharmacological measure has demonstrated some effect in treating nausea and vomiting in pregnant women?
Ginger -Clinical trials indicate that ginger can effectively reduce nausea and vomiting associated with motion sickness, pregnancy, and surgery.
A client receiving cancer chemotherapy has been prescribed aprepitant for nausea. The nurse should instruct the client to avoid which liquid?
Grapefruit juice -Foods and herbs are known to affect aprepitant concentration. Grapefruit juice decreases the metabolism of aprepitant, and this effect can last up to 24 hours. Therefore, grapefruit juice consumption can result in a cumulative increase in the serum level of aprepitant.
The nurse is caring for a client who has just had an episode of vomiting. What is the first intervention that the nurse would complete after the client has finished vomiting?
Help the client rinse his mouth -The nurse should immediately help the client rinse out his mouth which helps take away the taste and sensation of vomit.
Which would be most important for the nurse to do when administering a phenothiazine antiemetic to a patient?
Institute safety precautions -Adverse effects associated with phenothiazines are linked to their interference with normal CNS stimulation. The patient's risk for injury is high.
Medications are given post-operatively to prevent or treat severe nausea and vomiting associated with the surgery. What serotonin receptor antagonist would the nurse expect the surgeon to order?
Odansetron -Ondansetron, granisetron, dolasetron, and palonosetron are used to prevent or treat moderate to severe nausea and vomiting associated with cancer chemotherapy, radiation therapy, and post-operative status.
What antiemetic is the most common first-line drug for the treatment of postoperative nausea and vomiting?
Ondansetron -The 5-HT3 receptor antagonists are usually considered drugs of first choice for postoperative nausea and vomiting. Ondansetron is the prototype of the 5-HT3 receptor antagonists.
A client has been told that stimulation of their chemoreceptor trigger zone (CTZ) is responsible for their current symptoms. What nursing action indicates that the nurse is aware of the role of the CTZ?
Planning care to manage the client's nausea and vomiting -The CTZ, located in the brain is referred to as the vomiting center. Nausea and vomiting are experienced when this center is stimulated.
A client is experiencing nausea and vomiting as a response to radiation therapy. Which antiemetic agent is a phenothiazine administered to control nausea and vomiting?
Prochlorperazine (Compazine) -Prochlorperazine is a commonly used phenothiazine administered for nausea and vomiting related to radiation therapy.
A 1-year-old postoperative client has been experiencing repeated vomiting. What antiemetic drug has a black box warning against use in a client of this age?
Promethazine - black box warning alerts nurses that promethazine is contraindicated in children younger than 2 years of age because of the risk of potentially fatal respiratory depression.
The physician has prescribed an antiemetic for your 9-year-old patient to control nausea and vomiting. Which drug is the physician most likely to prescribe?
Promethazine -Promethazine is often the drug of choice with children, and it has established oral, rectal, and parenteral doses.
An older adult client is administered dimenhydrinate. Which is the priority nursing intervention for this client?
Protect from injury. -Dimenhydrinate causes drowsiness, especially in older adults, and therefore should be used cautiously. The nurse should protect the client from injury.
An older adult client with early-stage Alzheimer's disease has had hydroxyzine prescribed for nausea. When planning this client's care, the nurse should consequently identify what risk nursing diagnosis?
Risk for falls related to adverse effects of hydroxyzine -With hydroxyzine, adverse anticholinergic effects include drowsiness, dizziness, confusion, and blurred vision. These reactions increase the risk for falls, especially in the case of a client with an underlying cognitive disorder.
A female client is going on a cruise to Nova Scotia with her husband to celebrate their 15th wedding anniversary. She is concerned because she has experienced severe, debilitating seasickness in the past. What would the nurse expect the health care provider to order?
Scopolamine -Scopolamine is an anticholinergic drug that is effective in relieving nausea and vomiting associated with motion sickness and radiation therapy for cancer.
Which intervention has priority when caring for an older adult client who has been prescribed a phenothiazine for reported nausea?
The client is identified as a possible falls risk -Older adults are more likely to develop adverse effects associated with the use of these drugs. Safety measures may be needed if these effects occur and interfere with the patient's mobility and balance increasing their risk for falls.
Following administration of hydroxyzine, the nurse should assess the client for which side effect?
drowsiness -The use of hydroxyzine is associated with drowsiness.
An adult hospital client has been experiencing intractable nausea and vomiting for several hours, so the nurse has obtained a prescription for an antiemetic from the primary care provider. The prescription reads: "Promethazine 25 mg subcutaneously every 6 hours PRN." The nurse should contact the care provider to question what aspect of this prescription?
the route -A black box warning alerts nurses that promethazine is contraindicated for subcutaneous administration.