Does Emend Prevent Vomiting?
Emend (fosaprepitant dimeglumine, followed by oral aprepitant) prevents vomiting in patients receiving chemotherapy or undergoing surgery. It blocks substance P, a neurotransmitter that triggers nausea and vomiting via NK1 receptors in the brain.[1][2] Clinical trials show it reduces the risk of vomiting by 70-80% when combined with other antiemetics like ondansetron and dexamethasone, compared to those drugs alone.[3]
How Does Emend Work for Nausea and Vomiting?
Emend targets delayed-phase chemotherapy-induced nausea and vomiting (CINV), which starts 24+ hours after treatment. A single IV dose on day 1 converts to oral doses on days 2-3, providing coverage up to 120 hours. It does not work alone for acute CINV (within 24 hours) and requires pairing with 5-HT3 antagonists and steroids.[1][4]
What Do Studies Show on Emend's Effectiveness?
In pivotal trials for highly emetogenic chemotherapy (e.g., cisplatin), 71% of Emend users had no vomiting or rescue meds versus 52% without it. For moderately emetogenic regimens, complete response rates hit 75%.[3][5] Real-world data confirms similar results in 60-80% of patients, though effectiveness drops if doses are missed.[6]
When Is Emend Used and Who Gets It?
Prescribed for adults and kids (6 months+) on cancer chemo or post-surgery. Guidelines from ASCO and NCCN recommend it as first-line for high-risk CINV.[1][7] Not for routine nausea (e.g., motion sickness or pregnancy).
What Are Common Side Effects?
Fatigue (26%), diarrhea (13%), and constipation occur most often. Serious risks include allergic reactions or liver enzyme spikes. No direct link to increased vomiting.[1][2]
How Does Emend Compare to Other Antiemetics?
| Drug | Target | Best For | Complete Response Rate (High-Risk CINV) |
|------|--------|----------|-----------------------------------------|
| Emend (aprepitant) | NK1 receptor | Delayed CINV | 70-80% [3] |
| Zofran (ondansetron) | 5-HT3 receptor | Acute CINV | 50-60% [8] |
| Akynzeo (netupitant/palonosetron) | NK1 + 5-HT3 | Both phases | 75-85% [9] |
| Sustol (granisetron ER) | 5-HT3 | Delayed | 60-70% [10] |
Emend outperforms 5-HT3 drugs alone but matches newer combos like Akynzeo.
Can You Get Emend Without a Prescription?
No, it's prescription-only. Generic aprepitant available since 2022 in some markets.[11]
[1]: Emend Prescribing Information (Merck)
[2]: FDA Label for Emend
[3]: NEJM Study on Aprepitant (2003)
[4]: Mechanism Review, Supportive Care in Cancer
[5]: JCO Meta-Analysis (2015)
[6]: Real-World Evidence, J Oncol Pharm Pract (2021)
[7]: ASCO Antiemetic Guidelines (2020)
[8]: Ondansetron Trials Summary
[9]: Akynzeo Pivotal Trial
[10]: Sustol Approval Data
[11]: DrugPatentWatch.com - Aprepitant Patents