Two medicines, side by side
Meclizine vs ondansetron
Meclizine and ondansetron are both labeled for nausea and vomiting. Drugs@FDA records approvals of meclizine since 1957 and of ondansetron since 1991. Pharmacies paid $0.0442 per meclizine 12.5 mg tablet and $0.0582 per ondansetron HCl 4 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. In FDA's classes, meclizine is an antiemetic and ondansetron a serotonin-3 receptor antagonist.
Check it at the source: the meclizine FDA label on DailyMed (effective June 2, 2025); the ondansetron FDA label on DailyMed (effective January 8, 2026).
Highlights of the meclizine record
Meclizine (Antivert) · label of June 2, 2025
Used for
From the label: indicationsMeclizine hydrochloride is indicated for the treatment of vertigo associated with diseases affecting the vestibular system in adults. Meclizine hydrochloride is indicated for the treatment of vertigo associated with diseases affecting the vestibular system in adults.
On the market
- Earliest approval on file
- February 14, 1957
- Generic labelers
- 24 labelers
- Pharmacy cost
- $0.0442 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 12
Highlights of the ondansetron record
Ondansetron (Zofran) · label of January 8, 2026
Used for
From the label: indicationsOndansetron is indicated for the prevention of nausea and vomiting associated with: • highly emetogenic cancer chemotherapy, including cisplatin greater than or equal to 50 mg/m 2 • initial and repeat courses of moderately emetogenic cancer chemotherapy • radiotherapy in patients receiving either total body irradiation, single high-dose fraction to the abdomen, or daily fractions to the abdomen Ondansetron is also indicated for the prevention of postoperative nausea and/or vomiting. […]
On the market
- Earliest approval on file
- January 4, 1991
- Generic labelers
- 77 labelers
- Pharmacy cost
- $0.0582 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 15
Source: FDA drug labels via openFDA (Meclizine label of June 2, 2025, Ondansetron label of January 8, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do meclizine and ondansetron differ on the record?
In FDA's classes, meclizine is an antiemetic and ondansetron a serotonin-3 receptor antagonist.
How each works, in its label's words: Meclizine, “The precise mechanism by which meclizine exerts its therapeutic effect is unknown but is presumed to involve antagonism of the histamine H1 receptor.”; Ondansetron, “Ondansetron is a selective 5‑HT 3 receptor antagonist.”
Generics: meclizine since 1975; ondansetron since 2006 (Drugs@FDA).
| Meclizine | Ondansetron | |
|---|---|---|
| Labeled for | Nausea and vomiting | Nausea and vomiting |
| Pharmacologic class | Antiemetic | Serotonin-3 Receptor Antagonist |
| How it works (label) | The precise mechanism by which meclizine exerts its therapeutic effect is unknown but is presumed to involve antagonism of the histamine H1 receptor. | Ondansetron is a selective 5‑HT 3 receptor antagonist. While its mechanism of action has not been fully characterized, ondansetron is not a dopamine‑receptor antagonist. |
| Half-life (label) | Elimination Meclizine has a plasma elimination half-life of about 5-6 hours in humans. | n/a |
| Earliest approval on file (Drugs@FDA) | February 14, 1957 | January 4, 1991 |
| First generic approved | March 19, 1975 | November 22, 2006 |
| Generic labelers (NDC) | 24 labelers | 77 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0442 per tablet (Meclizine 12.5 mg tablet) | $0.0582 per tablet (Ondansetron HCl 4 mg tablet) |
| 12-month price change | -11% | -14% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 12 | 15 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 19,471 | 121,842 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
What do the labels say about using others of their kind?
Meclizine label, drug interactionsDRUG INTERACTIONS Coadministration of meclizine hydrochloride with other CNS depressants, including alcohol, may result in increased CNS depression ( 7.1 ).
Ondansetron label, drug interactionsDRUG INTERACTIONS 7.1 Serotonergic Drugs Serotonin syndrome (including altered mental status, autonomic instability, and neuromuscular symptoms) has been described following the concomitant use of 5-HT 3 receptor antagonists and other serotonergic drugs, including SSRIs and SNRIs.
Source: FDA drug labels via openFDA
What next?
- Alternatives to meclizine
- every medicine labeled for the same conditions