aprepitant

aprepitant (oral)

(a-prep-i-tant) ,

Emend

(trade name)

fosaprepitant (injection)

(fos-a-prep-i-tant) ,

Emend

(trade name) Pregnancy Category: B

Indications

Action

Pharmacokinetics

Time/action profile (antiemetic effect)

ROUTE	ONSET	PEAK	DURATION
PO	1 hr	4 hr*	24 hr
IV	rapid	end of infusion*	24 hr

*Blood level

Contraindications/Precautions

Adverse Reactions/Side Effects

Cardiovascular

• dizziness
• fatigue
• weakness

Dermatologic

• stevens-johnson syndrome (life-threatening)

Gastrointestinal

• diarrhea

Miscellaneous

• hiccups
• hypersensitivity reaction (flushing, erythema, dyspnea) (IV)

Interactions

Drug-Drug interaction

Aprepitant inhibits, induces, and is metabolized by the CYP3A4 enzyme system; it also induces the CYP2C9 system. Concurrent use with other medications that are metabolized by CYP3A4 may result in ↑ toxicity from these agents including docetaxel, paclitaxel, etoposide, irinotecan, ifosfamide, imatinib, vinorelbine, vinblastine, vincristine, midazolam, triazolam, and alprazolam ; concurrent use should be undertaken with caution.Concurrent use with drugs that significantly inhibit the CYP3A4 enzyme system including (ketoconazole, itraconazole, nefazodone, clarithromycin, ritonavir, nelfinavir, and diltiazem ) may ↑ blood levels and effects of aprepitant.Concurrent use with drugs that induce the CYP3A4 enzyme system including rifampin, carbamazepine, and phenytoin may ↓ blood levels and effects of aprepitant.↑ blood levels and effects of dexamethasone (regimen reflects a 50% dose reduction); a similar effect occurs with methylprednisolone (↓ IV dose by 25%, ↓ PO dose by 50% when used concurrently).May ↓ the effects of warfarin (careful monitoring for 2 wk recommended), oral contraceptives (use alternate method), and phenytoin.

Route/Dosage

Prevention of Nausea and Vomiting Associated with Highly Emetogenic Chemotherapy

Prevention of Nausea and Vomiting Associated with Moderately Emetogenic Chemotherapy

Prevention of Postoperative Nausea and Vomiting

Availability

Nursing implications

Nursing assessment

• Assess nausea, vomiting, appetite, bowel sounds, and abdominal pain prior to and following administration.
• Monitor hydration, nutritional status, and intake and output. Patients with severe nausea and vomiting may require IV fluids in addition to antiemetics.
• Assess for rash periodically during therapy. May cause Stevens-Johnson syndrome. Discontinue therapy if severe or if accompanied with fever, general malaise, fatigue, muscle or joint aches, blisters, oral lesions, conjunctivitis, hepatitis and/or eosinophilia.
• Lab Test Considerations: Monitor clotting status closely during the 2 wk period, especially at 7–10 days, following aprepitant therapy in patients on chronic warfarin therapy.
  • May cause mild, transient ↑ in alkaline phosphatase, AST, ALT, and BUN.
  • May cause proteinuria, erythrocyturia, leukocyturia, hyperglycemia, hyponatremia, and ↑ leukocytes.
  • May cause ↓ hemoglobin and WBC.

Potential Nursing Diagnoses

Risk for deficient fluid volume (Indications)
Imbalanced nutrition: less than body requirements (Indications)

Implementation

• For chemotherapy, aprepitant is given as part of a regimen that includes a corticosteroid and a 5-HT₃ antagonist (see Route/Dosage).
• Oral: Administer daily for 3 days. Day 1—administer 125 mg 1 hr prior to chemotherapy. Days 2 and 3—administer 80 mg once in the morning. May be administered without regard to food.

• Intravenous Administration

• Single-Dose Regimen: Intermittent Infusion: Inject 5 mL of 0.9% NaCl for Injection into vial. Swirl gently; avoid shaking or jetting saline into vial. Diluent: Prepare an infusion bag of 145 mL 0.9% NaCl. Withdraw entire volume from vial, and transfer to infusion bag for a total volume of 150 mL. Concentration: 1 mg/mL. Gently invert bag 2–3 times. Solution is stable for 24 hr at room temperature. Inspect solution for particulate matter. Do not administer solutions that are discolored or contain particulate matter.
• Rate: Infuse over 20–30 min.
• 3-Day Regimen: Intermittent Infusion: Inject 5 mL of 0.9% NaCl for Injection into vial. Swirl gently; avoid shaking or jetting saline into vial. Diluent: Prepare an infusion bag of 110 mL 0.9% NaCl. Withdraw entire volume from vial, and transfer to infusion bag for a total volume of 115 mL. Concentration: 1 mg/mL. Gently invert bag 2–3 times. Solution is stable for 24 hr at room temperature. Inspect solution for particulate matter. Do not administer solutions that are discolored or contain particulate matter.
• Rate: Administer over 15 min.
• Y-Site Compatibility: dexamethasone, granisetron, methylprednisolone, ondansetron, palonosetron
• Solution Incompatibility: Incompatible with solutions containing divalent cations (calcium, magnesium) including LR and Hartmann's solution.

Patient/Family Teaching

• Instruct patient to take aprepitant as directed. Direct patient to read the Patient Package Insert before starting therapy and to reread it each time the prescription is renewed.
• Instruct patient to notify health care professional if nausea and vomiting occur prior to administration.
• Advise patient to notify health care professional immediately if symptoms of hypersensitivity reaction (hives, rash, itching, redness of the face/skin, difficulty in breathing or swallowing) occur.
• Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications.
• Caution patient that fosaprepitant may decrease the effectiveness of oral contraceptives. Advise patient to use alternate nonhormonal methods of contraception during and for 1 mo following treatment. Advise patient to notify health care professional if pregnancy is planned or suspected or if breast feeding.
• Advise patient and family to use general measures to decrease nausea (begin with sips of liquids and small, nongreasy meals; provide oral hygiene; remove noxious stimuli from environment).

Evaluation/Desired Outcomes

• Decreased nausea and vomiting associated with chemotherapy.
• Prevention of postoperative nausea and vomiting.