Emend

Emend,

a trademark for aprepitant.

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aprepitant

Emend

Pharmacologic class: Substance P and neurokinin-1 antagonist

Therapeutic class: Adjunctive antiemetic

Pregnancy risk category B

Action

Augments antiemetic activity of ondansetron (a 5-hydroxytryptamine₃-receptor antagonist) and dexamethasone. Also inhibits cisplatin-induced emesis.

Availability

Capsules: 40 mg, 80 mg, 125 mg

⊘Indications and dosages

➣ To prevent acute and delayed nausea and vomiting caused by highly emetogenic cancer chemotherapy

Adults: 125 mg P.O. 1 hour before chemotherapy on day 1; then 80 mg P.O. once daily in morning on days 2 and 3. Give with 12 mg dexamethasone P.O. and 32 mg ondansetron I.V. on day 1, and with 8 mg dexamethasone P.O. on days 2 to 4.

➣ Prevention of postoperative nausea and vomiting

Adults: 40 mg P.O. once within 3 hours before induction anesthesia

Contraindications

• Hypersensitivity to drug
• Concurrent pimozide, terfenadine, astemizole, or cisapride therapy
• Breastfeeding

Precautions

Use cautiously in:
• patients receiving concurrent warfarin or CYP3A4 inhibitors
• pregnant patients.

Administration

• Give 1 hour before chemotherapy on day 1, together with other antiemetics as prescribed.
• Give on mornings of days 2 and 3.

Route	Onset	Peak	Duration
P.O.	Unknown	Unknown	Unknown

Adverse reactions

CNS: dizziness, neuropathy, headache, insomnia, asthenia, fatigue

EENT: tinnitus

GI: nausea, vomiting, constipation, diarrhea, epigastric discomfort, gastritis, heartburn, abdominal pain, anorexia

Hematologic: neutropenia

Other: fever, dehydration, hiccups

Interactions

Drug-drug. CYP3A4 inducers (carbamazepine, phenytoin, rifampin): decreased aprepitant blood level

CYP3A4 inhibitors (azole antifungals, clarithromycin, nefazodone, ritonavir): increased aprepitant blood level

Dexamethasone, methylprednisolone: increased steroid exposure

Docetaxel, etoposide, ifosfamide, imatinib, irinotecan, paclitaxel, vinblastine, vincristine, vinorelbine: increased blood levels of these drugs

Hormonal contraceptives: decreased contraceptive efficacy

Paroxetine: decreased efficacy of either drug

Pimozide: increased blood level and toxic effects of aprepitant

Tolbutamide, warfarin: CYP2C9 induction, decreased efficacy of these drugs

Patient monitoring

• Monitor neurologic status. Institute measures to prevent injury as needed.
• Assess nutritional and hydration status.
• Monitor CBC.

Patient teaching

• Tell patient that drug may cause CNS effects. Explain that he'll be monitored to ensure his safety.
• Advise patient to minimize GI upset by eating small, frequent servings of food and drinking plenty of fluids.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, hearing, strength, balance, and alertness.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs mentioned above.