Two medicines, side by side
Cyclobenzaprine vs tizanidine
Cyclobenzaprine and tizanidine are both labeled for muscle spasms and spasticity. Drugs@FDA records approvals of cyclobenzaprine since 1977 and of tizanidine since 1996. Pharmacies paid $0.0171 per cyclobenzaprine 10 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. Cyclobenzaprine's other strengths are brand-only: $29.61 per tablet (Tonmya 2.8 mg tablet sl). In FDA's classes, cyclobenzaprine is a muscle relaxant and tizanidine a central alpha-2 adrenergic agonist.
Check it at the source: the cyclobenzaprine FDA label on DailyMed (effective February 21, 2025); the tizanidine FDA label on DailyMed (effective January 2, 2026).
Highlights of the cyclobenzaprine record
Cyclobenzaprine (Flexeril) · label of February 21, 2025
Used for
From the label: indicationsCyclobenzaprine hydrochloride tablets, USP are indicated as an adjunct to rest and physical therapy for relief of muscle spasm associated with acute, painful musculoskeletal conditions. Improvement is manifested by relief of muscle spasm and its associated signs and symptoms, namely, pain, tenderness, limitation of motion, and restriction in activities of daily living. […]
On the market
- Earliest approval on file
- August 26, 1977
- Generic labelers
- 59 labelers
- Pharmacy cost
- $0.0171 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 5
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 (Cyclobenzaprine label of February 21, 2025, Tizanidine label of January 2, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do cyclobenzaprine and tizanidine differ on the record?
In FDA's classes, cyclobenzaprine is a muscle relaxant and tizanidine a central alpha-2 adrenergic agonist.
Half-life, in each label's words: Cyclobenzaprine, “Cyclobenzaprine is eliminated quite slowly, with an effective half-life of 18 hours (range 8 to 37 hours; n=18); …”; Tizanidine, “Elimination Metabolism Tizanidine has a half-life of approximately 2.5 hours (CV=33%).”
Generics: cyclobenzaprine since 1988; tizanidine since 2002 (Drugs@FDA).
| Cyclobenzaprine | Tizanidine | |
|---|---|---|
| Labeled for | Muscle spasms and spasticity, Nerve pain and fibromyalgia | 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) | Cyclobenzaprine is eliminated quite slowly, with an effective half-life of 18 hours (range 8 to 37 hours; n=18); plasma clearance is 0.7 L/min. | Elimination Metabolism Tizanidine has a half-life of approximately 2.5 hours (CV=33%). |
| Earliest approval on file (Drugs@FDA) | August 26, 1977 | November 27, 1996 |
| First generic approved | February 29, 1988 | June 27, 2002 |
| Generic labelers (NDC) | 59 labelers | 49 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0171 per tablet (Cyclobenzaprine 10 mg tablet) | $0.0331 per tablet (Tizanidine HCl 4 mg tablet) |
| 12-month price change | -10% | -12% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 5 | 9 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 50,442 | 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 do the labels say about using others of their kind?
Cyclobenzaprine label, warningsIf concomitant treatment with cyclobenzaprine hydrochloride and other serotonergic drugs is clinically warranted, careful observation is advised, particularly during treatment initiation or dose increases (see PRECAUTIONS :
Source: FDA drug labels via openFDA
What next?
- Alternatives to cyclobenzaprine
- every medicine labeled for the same conditions