Ondansetron (Zofran)

Antiemeticprescriptionoral · predicted

Selective 5-HT3 receptor antagonist, blocks serotonin at vagal afferents and chemoreceptor trigger zone. Gold standard antiemetic for chemotherapy-induced nausea and post-operative nausea. Widely used off-label for gastroenteritis, pregnancy nausea (controversial), and hyperemesis. Available oral tablet, ODT (orally disintegrating), IV, and IM. Multiple CYP metabolism (1A2, 2D6, 3A4). Generally well-tolerated; QTc prolongation at high IV doses.

Projected serum levels — 4 mg, as needed (shown daily)

Maintenance schedule: 4 mg as needed (shown daily) (oral).

Modeled steady state after ~1 days: peak ≈ 1.8 mg, trough ≈ 0.016 mg body load. Population-based estimate over 15 days for a 4 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category: Antiemetic
Route modeled: Oral
Model confidence: predicted
Half-life: 4 h
Common dose: 4 mg
Suggested maximum: 24 mg/day
Reference dose range: 2–24 mg (single dose)
Suggested cadence: as needed (shown daily)
Validated against: 8 mg oral — Cmax 0.030 mg/L at 2 h

Documented interactions

danger
1P-LSD (1-Propionyl-LSD) + Ondansetron (Zofran) Serotonin risk
1P-LSD (1-Propionyl-LSD) and Ondansetron (Zofran) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental status).
danger
25I-NBOMe + Ondansetron (Zofran) Serotonin risk
25I-NBOMe and Ondansetron (Zofran) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental status).
danger
2C-I (2,5-Dimethoxy-4-iodophenethylamine) + Ondansetron (Zofran) Serotonin risk
2C-I (2,5-Dimethoxy-4-iodophenethylamine) and Ondansetron (Zofran) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental status).
danger
2C-B (4-Bromo-2,5-dimethoxyphenethylamine) + Ondansetron (Zofran) Serotonin risk
2C-B (4-Bromo-2,5-dimethoxyphenethylamine) and Ondansetron (Zofran) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental status).
danger
4-AcO-DMT (Psilacetin) + Ondansetron (Zofran) Serotonin risk
4-AcO-DMT (Psilacetin) and Ondansetron (Zofran) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental status).
danger
5-MeO-DMT (5-Methoxy-N,N-dimethyltryptamine) + Ondansetron (Zofran) Serotonin risk
5-MeO-DMT (5-Methoxy-N,N-dimethyltryptamine) and Ondansetron (Zofran) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental…

Serum checks 206 modeled interaction pairings for ondansetron (zofran) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.

Research behind this entry

Ondansetron for the treatment of nausea and vomiting in the emergency department: a systematic review Furyk JS et al. · Annals of Emergency Medicine, 2015 DOI
Systematic review of 6 RCTs confirming ondansetron effective for reducing ED nausea/vomiting across multiple etiologies, with NNT of 5 for complete resolution of nausea within 30 minutes.
Clinical pharmacokinetics of ondansetron: a review Roila F, Del Favero A · Clinical Pharmacokinetics, 1995 DOI
PK review establishing ondansetron half-life of 3-5 hours, 60% oral bioavailability, extensive hepatic metabolism by CYP1A2/2D6/3A4, and linear pharmacokinetics with no dose-adjustment needed for renal impairment.

2 published studies referenced in the app, each with a plain-language summary.