chapter 36 pharm 2

- dilute with saline to aviod burning sensations. 10ml.

(Phenergan)

Several medications interact with promethazine, increasing its effects (Box 36.1). Herbal interactions with promethazine have been reported with kava kava, St. John's wort, and valerian; an increased risk of CNS depression is a possibility. No herbs or foods that decrease the effects of promethazine have been identified

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Assess the patient's condition and report to the health care provider if nausea and vomiting occur. In some instances, a drug (e.g., digoxin, an antibiotic) may need to be discontinued or reduced in dosage. In other instances (e.g., paralytic ileus, GI obstruction), preferred treatment is restriction of oral intake and nasogastric intubation. Suggest that a woman eat dry crackers before rising in the morning and ingestion of small frequent protein meals to help prevent nausea and vomiting associated with pregnancy.

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Avoid administering oral intake of food, fluids, and drugs during acute episodes of nausea and vomiting. Oral intake may increase vomiting and risks of fluid and electrolyte imbalances. Minimize activity during acute episodes of nausea and vomiting. Lying down and resting quietly are often helpful. Nursing Interventions (cont.)-Review on own Give supportive care during vomiting episodes. Give replacement fluids and electrolytes. Offer small amounts of food and fluids orally when tolerated and according to patient preference. Record vital signs, intake and output, and body weight at regular intervals if nausea or vomiting occurs frequently. Decrease environmental stimuli when possible (e.g., noise, odors). Allow the patient to lie quietly in bed when nauseated. Decreasing motion may decrease stimulation of the vomiting center in the brain. Nursing Interventions (cont.)-Review on own Help the patient rinse his or her mouth after vomiting. Rinsing decreases the bad taste and corrosion of tooth enamel caused by gastric acid. Provide requested home remedies when possible (e.g., a cool, wet washcloth to the face and neck). Provide appropriate education for any drug therapy.

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Many medications interact with hydroxyzine, increasing its effects (Box 36.3). Several medications that can cause CNS depression, such as sedatives, tranquilizers, muscle relaxants, and antidepressants, can have an increased sedative effect with the concomitant use of hydroxyzine. No herbs or foods appear to decrease or increase the effects of hydroxyzine

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Phenothiazines are metabolized in the liver. Therefore, the presence of liver disease (e.g., cirrhosis, hepatitis) may slow metabolism and prolong drug elimination half-life, with resultant accumulation and increased risk of adverse effects. Thus, the drugs should be used cautiously in patients with hepatic impairment. Cholestatic jaundice may occur with promethazine.

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Aprepitant is orally absorbed, reaching peak levels 4 hours after administration. It is highly protein bound. The drug is metabolized in the liver and is excreted in urine and feces. Because aprepitant undergoes extensive hepatic metabolism by CYP450 enzyme systems, it has the potential for multiple drug interactions. After administration, the IV form, fosaprepitant, is rapidly converted in the body to aprepitant.

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Administer antiemetic drugs ____ before a nausea-producing event, when possible (e.g., radiation therapy, cancer chemotherapy, travel). Adjust the timing of any oral drugs that cause gastric irritation, nausea, and vomiting by taking with or just after food. For any drug likely to cause nausea and vomiting, check reference sources to determine whether it can be given with food without altering beneficial effects.

30 to 60 minutes

Prescribers often order aprepitant as part of combination therapy along with a ____ and corticosteroids to treat both acute and delayed nausea and vomiting associated with chemotherapy

5-HT3 receptor antagonist

Nonpharmacologic techniques have become an acceptable adjunct to antiemetic drug therapy. The use of herbal supplements has also received support. Techniques include

Acupuncture and acupressure Herbal supplements- peppermint- decreases nausea. Apples are good too.

Identify risk factors for nausea and vomiting (e.g., digestive or other disorders in which nausea and vomiting are symptoms; drugs associated with nausea and vomiting). Interview regarding frequency, duration, and precipitating causes of nausea and vomiting. Also, question the patient about accompanying signs and symptoms, characteristics of vomitus (amount; color; odor; presence of abnormal components, such as blood), and any measures that relieve nausea and vomiting. When possible, observe and measure the vomitus.

Antiemetics

Medications used to prevent/treat nausea and vomiting

Antiemetics

are used primarily to prevent histamine from exerting its widespread effects on body tissues

Antihistamines

is used in patients with cancer who are receiving chemotherapy. The American Society of Clinical Oncology's antiemetic guidelines recommend the use of aprepitant in combination with a serotonin receptor antagonist and dexamethasone with chemotherapeutic drugs with high emetic risk. The drug is also recommended as part of a chemotherapy regimen in protocols including anthracycline, cyclophosphamide, and other chemotherapeutic agents known to cause moderate emetic risk.

Aprepitant

is well tolerated, with the most common adverse effects being fatigue, weakness, dizziness, abnormal heart rhythm, headache, and hiccups. Infusion site pain has been reported with IV administration.

Aprepitant

Drug Class- Substance P/neurokinin 1 receptor antagonist Prototype- ___

Aprepitant (Emend)

___, which is more commonly used in the treatment of psychosis and psychotic symptoms in other disorders (see Chap. 55), is also used with intractable hiccups and treatment of nausea and vomiting associated with anesthesia.

Chlorpromazine (Thorazine)

is a cannabinoid (derivative of marijuana) used in the management of nausea and vomiting associated with anticancer drugs and unrelieved by other drugs.

Dronabinol

Other Drugs in the Class Chlorpromazine (Thorazine) Perphenazine (Trilafon) Prochlorperazine (Compazine)

Drug Class-Phenothiazines

Symptoms of nausea and vomiting may accompany almost any illness or stress situation. Causes of nausea and vomiting include the following:

Gastrointestinal (GI) disorders, including infection or inflammation in the GI tract, liver, gallbladder, or pancreas; impaired GI motility and muscle tone (e.g., gastroparesis); and overeating or ingestion of foods or fluids that irritate the GI mucosa Cardiovascular, infectious, neurologic, or metabolic disorders Adverse effects of drug therapy; nausea and vomiting are the most common. Although the symptoms may occur with most drugs, they are especially associated with alcohol, aspirin, digoxin, anticancer drugs, antimicrobials, estrogen preparations, and opioid analgesics. Pain and other noxious stimuli, such as unpleasant sights and odors Emotional disturbances; physical or mental stress Radiation therapy Motion sickness Postoperative status, which may include pain, impaired GI motility, and receiving various medications Pregnancy Migraines

Foods and herbs are also known to affect aprepitant concentrations. ____increases the serum levels of aprepitant. St. John's wort is known to cause a decrease in serum levels.

Grapefruit juice

Antihistamines used as antiemetic agents are the "classic" antihistamines or ____ (as differentiated from cimetidine and related drugs, which are H2 receptor blocking agents).

H1 receptor blocking agents

____ may be effective in treating nausea and vomiting and preventing and treating motion sickness. _____ is also used as a sedative to treat anxiety. Additionally, the drug is given in combination with other medications during anesthesia.

Hydroxyzine

Drug Class- Antihistamines Prototype- ___

Hydroxyzine (Vistaril, Atarax)

- its a pro-kinetic medications. It promotes movement of substances through the GI tract. Used in patients who have GERDS. Take 30 min before bed time or 30 min before meal. Not for patients with seizure disorders. Might see seizure type movements. Less than 10mg you can give IV, greater than 10mg you need to dilute with 50ml with dextro 5% in water or lactated ringers and hang over 15 min period.

Metoclopramide ( Reglan)

Side Effects- EPS, sedation, diarrhea Contraindications- asmtha, narrow angle glacoma., urinary retention, seizures Nursing Indications Long term use may lead to Tardive Dsykinesia- stink tongue out. Interact with other CNS depressants, antihypertensive meds,

Metoclopramide ( Reglan)

Aprepitant exerts its antiemetic effect by blocking the activity of substance P at ___ receptors in the brain, inhibiting the signal to the brain that causes nausea. The drug has little or no effect on serotonin, dopamine, or corticosteroid receptors.

NK1

: unpleasant sensation of abdominal discomfort accompanied by a desire to vomit

Nausea

Diarrhea is a common adverse effect; therefore, the nurse also needs to assist patients and caregivers with appropriate use of the drugs and other interventions to prevent fluid and electrolyte depletion.

Ondansetron

is used to prevent or treat moderate to severe nausea and vomiting associated with cancer chemotherapy, radiation therapy, and postoperative status.

Ondansetron

Drug Class- 5-HT3 (serotonin) receptor antagonists Prototype-

Ondansetron (Zofran)

Take 1 hr before oral sugery. IV onset immediately. Bioavaliabilty is slightly increased with the presents of food. May impair thinking or reactions. No driving.

Ondasetron

These meds are neuroleptics

Phenothiazines

are central nervous system (CNS) depressants that are used for a variety of reasons, including the prevention and treatment of nausea and vomiting.

Phenothiazines

is a hyperosmolar solution with phosphoric acid. This drug is thought to reduce smooth muscle contraction in the GI tract and is available as an over-the-counter medication in syrup form.

Phosphorated carbohydrate solution (Emetrol)

block dopamine receptors. Side effect is EBS- gives u seizure type movements.

Prochlorperazine (Compazine)

is rapidly absorbed following oral administration and undergoes extensive first-pass metabolism in the liver. Clinical effects are apparent within 20 minutes after oral, intramuscular, or rectal administration; the effects last 4 to 6 hours. Metabolism occurs in the liver, with excretion in the urine.

Promethazine

is used for the prevention and treatment of nausea and vomiting associated with surgery, anesthesia, migraines, chemotherapy, and motion sickness.

Promethazine

Drug Class-Phenothiazines Prototype-

Promethazine (Phenergan)

___, an anticholinergic drug (see Chap. 47), is effective in relieving nausea and vomiting associated with motion sickness and radiation therapy. It is available as a transdermal patch, which is often used to prevent motion sickness.

Scopolamine

is a peptide neurotransmitter in the neurokinin family. It plays a role in mediating acute chemotherapy-induced nausea and vomiting (along with serotonin) and is believed to be the primary mediator of delayed nausea and vomiting associated with chemotherapy

Substance P

: expulsion of stomach contents through the mouth

Vomiting

Hydroxyzine and other antihistamines are thought to relieve nausea and vomiting by blocking the action of in the brain.

acetylcholine

In children, the recommended dosage of hydroxyzine is based on

age and weight

Use measures to prevent or minimize nausea and vomiting. Assist patients to identify situations that cause or aggravate nausea and vomiting. Avoid exposure to stimuli when feasible (e.g., unpleasant sights and odors; excessive ingestion of food, alcohol, or nonsteroidal anti-inflammatory drugs). Administer analgesics before painful diagnostic tests and dressing changes or other therapeutic measures may be helpful, as pain may cause nausea and vomiting.

antiemtics

Other Drugs in the Class Dimenhydrinate (Dramamine)- motion sickness. Meclizine (Antivert, Bonine) antivert. Treats vertigo (dizziness).

antihistamines

The nurse assesses for the absence of nausea and vomiting after chemotherapy or during the postoperative period.

aprepitant

The nurse observes for the presence of adverse effects, such as fatigue, weakness, dizziness, headache, or hiccups. Additionally, it is necessary to assess for a normal heart rhythm.

aprepitant

Patients should take aprepitant by mouth as directed with a full glass of water, with or without food. Typically, they take the first dose is taken 1 hour before ____ and then daily in the morning for the next 2 days after the chemotherapy treatment.

chemotherapy

When administering 5-HT3 receptor antagonists before cancer chemotherapy, the nurse should also be prepared to administer which of the following adjunctive medications?

dexamethasone

Adverse effects of ondansetron are usually mild to moderate. Common ones include

diarrhea, headache, dizziness, constipation, fatigue, transient elevation of liver enzymes, and pain at the injection site.

A woman sends her partner to the store to purchase an over-the-counter product to resolve the vomiting she has experienced during a migraine. She has a history of diabetes mellitus and hypertension. She has an appointment with her health care provider in the morning. Which of the following drugs would be the best for the partner to purchase?

dimenhydrinate (Dramamine)

Promethazine and other phenothiazines have widespread effects on the body. The therapeutic effects in nausea and vomiting are attributed to their ability to block _____ from receptor sites in the brain and CTZ.

dopamine

With hydroxyzine, adverse anticholinergic effects include

drowsiness, dizziness, confusion, dry mouth, thickened respiratory secretions, blurred vision, urinary retention, and tachycardia.

The nurse assesses for the absence of nausea and vomiting.

hydroxyzine

The nurse assesses for the presence of anticholinergic effects, including blurred vision, urinary retention, constipation, thick secretions, and blurred vision. Patients with narrow-angle glaucoma, prostatic hyperplasia, and asthma are at greater risk for adverse effects.

hydroxyzine

When administered orally, ____ is rapidly absorbed from the GI tract, with its effect noticeable within 30 minutes. The drug is metabolized in the liver, and the main metabolite is cetirizine. The half-life of ____ is, on average, 14 hours for adults, but it can be as short as 5 hours for small children and as long as 30 hours for elderly people. ______ is excreted into the urine in the form of its metabolites.

hydroxyzine

because hydroxyzine is metabolized in the ___, dosage adjustments and more intensive monitoring of adverse effects may be required in people with hepatic impairment.

liver

Oral ___ is well absorbed from the GI tract and undergoes some first-pass metabolism. The drug's half-life is 3 to 5.5 hours in most patients and 9 to 20 hours in patients with moderate or severe liver impairment. With the oral form, action begins in 30 to 60 minutes and peaks in about 2 hours. With the IV form, onset and peak of drug action are immediate. The bioavailability is slightly increased by the presence of food but is unaffected by antacids.

ondansetron

Because headache and diarrhea are the most common adverse effects, the nurse gives special attention when assessing for these effects.

ondasetron

The nurse assesses for verbal reports of decreased nausea and the absence of vomiting.

ondasetron

The 5-HT3 receptor antagonists are usually considered drugs of first choice for

postoperative nausea and vomiting.

Older adults may have increased concerns with the adverse anticholinergic effects (e.g., dizziness, acute confusion, delirium, dry mouth, tachycardia, blurred vision, urinary retention, constipation).

promethazine

The nurse assesses for associated adverse anticholinergic effects (dry mouth, blurred vision, urinary retention, constipation, acute confusion, dizziness, tachycardia). It is necessary to be aware that hallucinations, convulsions, and sudden death may occur with excessive doses. The nurse also assesses tissue integrity with injection of the drug because the drug may cause severe tissue injury; burning and pain at the IV site justify immediate discontinuation of the drug.

promethazine

With ____, common side effects include blurred vision, urinary retention, dry mouth, photosensitivity, drowsiness, and confusion.

promethazine

____ is contraindicated in children younger than 2 years of age because of the risk of potentially fatal respiratory depression. Additionally, promethazine should not be used in children with hepatic disease, Reye's syndrome, a history of sleep apnea, or a family history of sudden infant death syndrome.

promethazine

The nurse observes for prevention or resolution of nausea and vomiting.

prometthazine

ontraindications to aprepitant include known hypersensitivity to the drug or use in combination with

ranolazine, pimozide, or cisapride.

The nurse teaches patients taking promethazine to use the lowest effective dosage and not to take other drugs with ____ effects concurrently

respiratory depressant

Ondansetron and the other 5-HT3 receptor antagonists antagonize___ receptors, preventing their activation by the effects of emetogenic drugs and toxins.

serotonin

promethazine is contraindicated for ____ administration. The preferred route of administration is intramuscular, which reduces risk of surrounding muscle and tissue damage.

subcutaneous

Because hydroxyzine is excreted in the ___, dosage adjustments and more intensive monitoring of adverse effects may be required in people with renal impairment.

urine

Aprepitant induces the metabolism of ___. It is necessary to monitor the international normalized ratio for 2 weeks after treatment is initiated, especially for the first 7 to 10 days.

warfarin