Home Drug Guide Fosaprepitant Dimeglumine

Drug Guide

Generic Name

Fosaprepitant Dimeglumine

Brand Names Emend, Focinvez

Classification

Therapeutic: Antiemetic

Pharmacological: Neurokinin-1 (NK1) receptor antagonist

FDA Approved Indications

  • Prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of chemotherapy, including high-dose chemotherapy regimens.

Mechanism of Action

Fosaprepitant is a prodrug of aprepitant, which selectively antagonizes substance P/neurokinin 1 (NK1) receptors in the central nervous system, blocking the emetic signaling pathway.

Dosage and Administration

Adult: 150 mg IV administered as a single dose approximately 30 minutes prior to chemotherapy.

Pediatric: Not approved for pediatric use; safety and efficacy not established.

Geriatric: Adjust dosing based on renal and hepatic function; no specific dose adjustment required solely based on age.

Renal Impairment: No adjustment recommended, but cautious use advised in severe impairment.

Hepatic Impairment: Adjust dose in severe hepatic impairment; consult prescribing information.

Pharmacokinetics

Absorption: Rapid conversion from prodrug to active form, with rapid distribution.

Distribution: Widely distributed in tissues, crosses the blood-brain barrier.

Metabolism: Metabolized primarily in the liver via CYP3A4.

Excretion: Excreted mainly in feces; minimal renal excretion.

Half Life: Approximately 9-13 hours for the active metabolite.

Contraindications

  • Hypersensitivity to fosaprepitant or any component of the formulation.

Precautions

  • Use with caution in patients with hepatic impairment; monitor for drug interactions, especially with CYP3A4 substrates.

Adverse Reactions - Common

  • Hiccups (Frequent)
  • Fatigue (Less frequent)

Adverse Reactions - Serious

  • Hypersensitivity reactions (rash, anaphylaxis) (Rare)
  • Elevated liver enzymes (Uncommon)

Drug-Drug Interactions

  • CYP3A4 substrates (may increase levels)
  • Corticosteroids (may require dose adjustment)
  • Warfarin (potential interaction)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for signs of allergic reactions, nausea, vomiting.

Diagnoses:

  • Risk for dehydration due to vomiting.

Implementation: Administer IV infusion over 30 minutes prior to chemotherapy; monitor infusion site.

Evaluation: Assess effectiveness in preventing nausea and vomiting.

Patient/Family Teaching

  • Report any allergic symptoms immediately.
  • Take antiemetics as prescribed.
  • Maintain hydration.

Special Considerations

Black Box Warnings:

  • Use with caution in patients receiving therapies with significant CYP3A4 interactions; potential for decreased effectiveness of oral contraceptives.

Genetic Factors: Genetic variations in metabolizing enzymes may affect drug levels.

Lab Test Interference: May elevate liver function tests transiently.

Overdose Management

Signs/Symptoms: Unknown, but may include hypersensitivity or infusion reactions.

Treatment: Supportive care; symptomatic management; no specific antidote.

Storage and Handling

Storage: Store at room temperature, away from light and moisture.

Stability: Stable under recommended storage conditions.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.