FDA pharmacologic class
Serotonin-3 Receptor Antagonist
4 medicines are in FDA's class of serotonin-3 receptor antagonists: ondansetron, palonosetron (Posfrea), alosetron (Lotronex) and granisetron (Sustol); 2 combination products also contain one. 4 of the 6 are listed from generic labelers (FDA NDC Directory, October 8, 2026). The lowest pharmacy cost is ondansetron hcl 4 mg tablet at $0.0582 per tablet (NADAC).
Which medicines are serotonin-3 receptor antagonist?
| Medicine | Brand names | Generic labelers (all forms) | Pharmacy cost | Boxed warning | Shortage | Recalls since 2012 |
|---|---|---|---|---|---|---|
| Ondansetron | none listed | 77 labelers | $0.0582 per tablet 4 mg tablet | No | No current entry | 15 |
| Palonosetron | Posfrea | 13 labelers | n/a | No | A presentation being discontinued | 0 |
| Alosetron | Lotronex | 6 labelers | $2.02 per tablet 0.5 mg tablet | Yes | No current entry | 0 |
| Granisetron | Sustol, Sancuso, Granisol | 8 labelers | $1.31 per tablet 1 mg tablet | No | No current entry | 1 |
| Fosnetupitant and palonosetron | Akynzeo | none listed | n/a | No | No current entry | 0 |
| Netupitant and palonosetron | Akynzeo | none listed | n/a | No | No current entry | 0 |
Source: FDA Established Pharmacologic Class (NDC Directory, openFDA); CMS NADAC of October 7, 2026; FDA shortages and recalls (FDA files October 8, 2026)
What do pharmacies pay?
Each medicine's most widely listed form, per unit, in the NADAC survey: what pharmacies paid, not what a patient pays; strengths differ, so compare like with like.
Source: CMS National Average Drug Acquisition Cost (NADAC) survey, October 7, 2026: what retail pharmacies paid per unit; not a counter price