Two medicines, side by side
Orphenadrine vs tizanidine
Orphenadrine and tizanidine are both labeled for muscle spasms and spasticity. Drugs@FDA records approvals of orphenadrine since 1957 and of tizanidine since 1996. Pharmacies paid $0.454 per orphenadrine ER 100 mg tablet and $0.0331 per tizanidine HCl 4 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. In FDA's classes, orphenadrine is a muscle relaxant and tizanidine a central alpha-2 adrenergic agonist.
Check it at the source: the orphenadrine FDA label on DailyMed (effective September 10, 2025); the tizanidine FDA label on DailyMed (effective January 2, 2026).
Highlights of the orphenadrine record
Orphenadrine (Disipal) · label of September 10, 2025
Used for
From the label: indicationsOrphenadrine citrate extended-release tablets are indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomfort associated with acute painful musculoskeletal conditions.
On the market
- Earliest approval on file
- May 10, 1957
- Generic labelers
- 17 labelers
- Pharmacy cost
- $0.454 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 3
Highlights of the tizanidine record
Tizanidine (Zanaflex) · label of January 2, 2026
Used for
From the label: indicationsZanaflex is indicated for the treatment of spasticity in adults. Zanaflex is a central alpha-2-adrenergic agonist indicated for the treatment of spasticity.
On the market
- Earliest approval on file
- November 27, 1996
- Generic labelers
- 49 labelers
- Pharmacy cost
- $0.0331 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 9
Source: FDA drug labels via openFDA (Orphenadrine label of September 10, 2025, Tizanidine label of January 2, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do orphenadrine and tizanidine differ on the record?
In FDA's classes, orphenadrine is a muscle relaxant and tizanidine a central alpha-2 adrenergic agonist.
Generics: orphenadrine since 1981; tizanidine since 2002 (Drugs@FDA).
| Orphenadrine | Tizanidine | |
|---|---|---|
| Labeled for | Muscle spasms and spasticity | Muscle spasms and spasticity |
| Pharmacologic class | Muscle Relaxant | Central alpha-2 Adrenergic Agonist |
| How it works (label) | n/a | Tizanidine is a central alpha-2-adrenergic receptor agonist and presumably reduces spasticity by increasing presynaptic inhibition of motor neurons. The effects of tizanidine are greatest on polysynaptic pathways. |
| Half-life (label) | n/a | Elimination Metabolism Tizanidine has a half-life of approximately 2.5 hours (CV=33%). |
| Earliest approval on file (Drugs@FDA) | May 10, 1957 | November 27, 1996 |
| First generic approved | July 16, 1981 | June 27, 2002 |
| Generic labelers (NDC) | 17 labelers | 49 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.454 per tablet (Orphenadrine ER 100 mg tablet) | $0.0331 per tablet (Tizanidine HCl 4 mg tablet) |
| 12-month price change | +6% | -12% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 3 | 9 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 621 | 41,179 |
| 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 next?
- Alternatives to orphenadrine
- every medicine labeled for the same conditions