fosaprepitant

Drug-drug:

May significantly ↑ levels of pimozide, which can ↑ risk of torsades de pointes; concurrent use contraindicated.
May ↑ levels and risk of toxicity of CYP3A4 substrates, including docetaxel, paclitaxel, etoposide, irinotecan, ifosfamide, imatinib, vinorelbine, vinblastine, vincristine, midazolam, triazolam, and alprazolam; concurrent use should be undertaken with caution.
Moderate or strong CYP3A4 inhibitors, including ketoconazole, itraconazole, nefazodone, clarithromycin, ritonavir, nelfinavir, and diltiazem, may ↑ levels and risk of toxicity.
Strong CYP3A4 inducers, including rifampin, carbamazepine, and phenytoin, may ↓ levels and effectiveness.
↑levels and risk of toxicity of dexamethasone (regimen reflects a 50% dose ↓); a similar effect occurs with methylprednisolone (↓ IV dose by 25%, ↓ PO dose by 50% when used concurrently).
May ↓ the effects of warfarin (carefully monitor INR for 2 wk), oral contraceptives (use alternate method), and phenytoin.

Availability ⬆ ⬇

(Generic available)

Lyophilized powder for injection (Emend): 150 mg/vial
Solution for injection (Focinvez): 3 mg/mL

Route/Dosage ⬆ ⬇

Prevention of Acute and Delayed Nausea and Vomiting Associated with Highly Emetogenic Chemotherapy

IV (Adults ): Emend or Focinvez: 150 mg given 30 min prior to chemotherapy on Day 1 only.
IV (Children 12–17 yr and ≥6 kg): Single-day chemotherapy regimen (Emend or Focinvez): 150 mg given 30 min prior to chemotherapy on Day 1 only; Multiday chemotherapy regimen (Emend): 115 mg given 30 min prior to chemotherapy on Day 1, then 80 mg once daily (as IV fosaprepitant or aprepitant oral capsules) for 2 days (Days 2 and 3); Multiday chemotherapy regimen (Focinvez): 115 mg given 30 min prior to chemotherapy on Day 1, then 80 mg once daily (as aprepitant oral capsules) for 2 days (Days 2 and 3).
IV (Children 2–<12 yr and ≥6 kg): Single-day chemotherapy regimen (Emend or Focinvez): 4 mg/kg (max dose = 150 mg) given 30 min prior to chemotherapy on Day 1 only; Multiday chemotherapy regimen (Emend): 3 mg/kg (max dose = 115 mg) given 30 min prior to chemotherapy on Day 1, then 2 mg/kg (max dose = 80 mg) (as IV fosaprepitant or aprepitant oral suspension) once daily for 2 days (Days 2 and 3); Multiday chemotherapy regimen (Focinvez): 3 mg/kg (max dose = 115 mg) given 30 min prior to chemotherapy on Day 1, then 2 mg/kg (max dose = 80 mg) (as aprepitant oral suspension) once daily for 2 days (Days 2 and 3).
IV (Children 6 mo-<2 yr and ≥6 kg): Single-day chemotherapy regimen (Emend or Focinvez): 5 mg/kg (max dose = 150 mg) given 30 min prior to chemotherapy on Day 1 only; Multiday chemotherapy regimen (Emend): 3 mg/kg (max dose = 115 mg) given 30 min prior to chemotherapy on Day 1, then 2 mg/kg (max dose = 80 mg) (as IV fosaprepitant or aprepitant oral suspension) once daily for 2 days (Days 2 and 3); Multiday chemotherapy regimen (Focinvez): 3 mg/kg (max dose = 115 mg) given 30 min prior to chemotherapy on Day 1, then 2 mg/kg (max dose = 80 mg) (as aprepitant oral suspension) once daily for 2 days (Days 2 and 3).

Prevention of Delayed Nausea and Vomiting Associated with Moderately Emetogenic Chemotherapy

IV (Adults ): Emend or Focinvez: 150 mg given 30 min prior to chemotherapy on Day 1 only.
IV (Children 12–17 yr and ≥6 kg): Single-day chemotherapy regimen (Emend or Focinvez): 150 mg given 30 min prior to chemotherapy on Day 1 only; Multiday chemotherapy regimen (Emend): 115 mg given 30 min prior to chemotherapy on Day 1, then 80 mg (as IV fosaprepitant or aprepitant oral capsules) once daily for 2 days (Days 2 and 3); Multiday chemotherapy regimen (Focinvez): 115 mg given 30 min prior to chemotherapy on Day 1, then 80 mg (as aprepitant oral capsules) once daily for 2 days (Days 2 and 3).
IV (Children 2–<12 yr and ≥6 kg): Single-day chemotherapy regimen (Emend or Focinvez): 4 mg/kg (max dose = 150 mg) given 30 min prior to chemotherapy on Day 1 only; Multiday chemotherapy regimen (Emend): 3 mg/kg (max dose = 115 mg) given 30 min prior to chemotherapy on Day 1, then 2 mg/kg (max dose = 80 mg) (as IV fosaprepitant or aprepitant oral suspension) once daily for 2 days (Days 2 and 3); Multiday chemotherapy regimen (Focinvez): 3 mg/kg (max dose = 115 mg) given 30 min prior to chemotherapy on Day 1, then 2 mg/kg (max dose = 80 mg) (as aprepitant oral suspension) once daily for 2 days (Days 2 and 3).
IV (Children 6 mo-<2 yr and ≥6 kg): Single-day chemotherapy regimen (Emend or Focinvez): 5 mg/kg (max dose = 150 mg) given 30 min prior to chemotherapy on Day 1 only; Multiday chemotherapy regimen (Emend): 3 mg/kg (max dose = 115 mg) given 30 min prior to chemotherapy on Day 1, then 2 mg/kg (max dose = 80 mg) (as IV fosaprepitant or aprepitant oral suspension) once daily for 2 days (Days 2 and 3); Multiday chemotherapy regimen (Focinvez): 3 mg/kg (max dose = 115 mg) given 30 min prior to chemotherapy on Day 1, then 2 mg/kg (max dose = 80 mg) (as aprepitant oral suspension) once daily for 2 days (Days 2 and 3).

US Brand Names ⬆ ⬇

Action ⬆ ⬇

Acts as a selective antagonist at substance P/neurokinin 1 (NK₁) receptors in the brain.

Therapeutic effects:

Decreased nausea and vomiting associated with chemotherapy.

Classifications ⬆ ⬇

Therapeutic Classification: antiemetics

Pharmacologic Classification: neurokinin antagonists

Pharmacokinetics ⬆ ⬇

Absorption: Following IV administration, fosaprepitant is rapidly converted to aprepitant, the active component. IV administration results in complete bioavailability.

Distribution: Crosses the blood brain barrier; remainder of distribution unknown.

Protein Binding: 95–99%.

Metabolism/Excretion: Mostly metabolized by the liver by the CYP3A4 isoenzyme; not renally excreted.

Half-Life: Aprepitant: 9–13 hr.

Time/Action Profile ⬆ ⬇

(antiemetic effect)

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

*Plasma concentrations.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take fosaprepitant as directed. Direct patient to read the Patient Package Insert before starting therapy and each time Rx renewed in case of changes.
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.
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).
Rep: Caution patient that fosaprepitant may decrease 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 breastfeeding.

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Indications ⬇

Contraind./Precautions ⬆ ⬇

Adv. Reactions/Side Effects ⬆ ⬇

Interactions ⬆ ⬇