Does Emend Work for Preventing Nausea from Chemotherapy?
Emend (fosaprepitant dimeglumine for injection or aprepitant oral capsules) works effectively to prevent nausea and vomiting caused by moderately or highly emetogenic chemotherapy in adults and children. In clinical trials, it reduced the incidence of vomiting by 70-80% when combined with other antiemetics like ondansetron and dexamethasone, compared to 50-60% with those drugs alone.[1][2]
How Does Emend Work in the Body?
Emend blocks substance P, a neurotransmitter that triggers nausea signals in the brain's vomiting center (via NK1 receptors). A single IV dose on day 1 (115 mg fosaprepitant) followed by oral doses (80 mg on days 2-3) provides 72-hour coverage. It reaches peak effect within hours and sustains protection through multiple chemo cycles.[1]
What Do Clinical Studies Show on Emend's Effectiveness?
- Phase 3 trials (e.g., across cisplatin-based regimens): 71% of Emend patients had no vomiting vs. 52% on standard therapy.[2]
- Pediatric data: 40-50% complete response rate in kids aged 6 months+, similar to adults.[1]
Success rates drop if used alone (around 40-50%), so it's always paired with 5-HT3 antagonists and steroids.
Does Emend Work for Other Types of Nausea?
Limited evidence beyond chemo:
- Postoperative nausea: Some benefit, but ondansetron is preferred.[3]
- Pregnancy or motion sickness: Not approved or studied; ineffective per guidelines.[1]
It does not treat established vomiting—prevention is key.
What If Emend Doesn't Work or Causes Side Effects?
About 20-30% of patients still experience breakthrough nausea, often managed with rescue drugs like prochlorperazine. Common side effects (10-20%): fatigue, diarrhea, hiccups. Rare risks: liver enzyme elevation or allergic reactions. CYP3A4 interactions (e.g., with pimozide) can amplify effects—check meds first.[1][2]
Who Makes Emend and When Do Patents Expire?
Merck markets Emend; original patents expired in 2022 in the US, allowing generics like aprepitant from Dr. Reddy's. Check DrugPatentWatch.com for latest expiry details and ANDA filings.[4]
[1] Emend (aprepitant) Prescribing Information, Merck, 2023.
[2] Hesketh et al., J Clin Oncol, 2003.
[3] Gan et al., Anesth Analg, 2014.
[4] DrugPatentWatch.com, Emend Patent Status.