Two medicines, side by side
Diazepam vs tizanidine
Diazepam and tizanidine are both labeled for muscle spasms and spasticity. Drugs@FDA records approvals of diazepam since 1963 and of tizanidine since 1996. Pharmacies paid $0.0283 per diazepam 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. In FDA's classes, diazepam is a benzodiazepine and tizanidine a central alpha-2 adrenergic agonist.
Check it at the source: the diazepam FDA label on DailyMed (effective August 11, 2026); the tizanidine FDA label on DailyMed (effective January 2, 2026).
Highlights of the diazepam record
Diazepam (Valium) · label of August 11, 2026
RISKS FROM CONCOMITANT USE WITH OPIOIDS; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required.
Used for
From the label: indicationsValium is indicated for the management of anxiety disorders or for the short- term relief of the symptoms of anxiety. Anxiety or tension associated with the stress of everyday life usually does not require treatment with an anxiolytic. In acute alcohol withdrawal, Valium may be useful in the symptomatic relief of acute agitation, tremor, impending or acute delirium tremens and hallucinosis. […]
On the market
- Earliest approval on file
- November 15, 1963
- Generic labelers
- 45 labelers
- Pharmacy cost
- $0.0283 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 8
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 (Diazepam label of August 11, 2026, Tizanidine label of January 2, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do diazepam and tizanidine differ on the record?
In FDA's classes, diazepam is a benzodiazepine and tizanidine a central alpha-2 adrenergic agonist.
Half-life, in each label's words: Diazepam, “The initial distribution phase has a half-life of approximately 1 hour, although it may range up to >3 hours.”; Tizanidine, “Elimination Metabolism Tizanidine has a half-life of approximately 2.5 hours (CV=33%).”
Only the diazepam label carries a boxed warning.
Generics: diazepam since 1985; tizanidine since 2002 (Drugs@FDA).
DEA schedule: diazepam CIV; tizanidine none.
| Diazepam | Tizanidine | |
|---|---|---|
| Labeled for | Anxiety, Muscle spasms and spasticity | Muscle spasms and spasticity |
| Pharmacologic class | Benzodiazepine | 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) | The initial distribution phase has a half-life of approximately 1 hour, although it may range up to >3 hours. | Elimination Metabolism Tizanidine has a half-life of approximately 2.5 hours (CV=33%). |
| Earliest approval on file (Drugs@FDA) | November 15, 1963 | November 27, 1996 |
| First generic approved | September 4, 1985 | June 27, 2002 |
| Generic labelers (NDC) | 45 labelers | 49 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0283 per tablet (Diazepam 10 mg tablet) | $0.0331 per tablet (Tizanidine HCl 4 mg tablet) |
| 12-month price change | -5% | -12% |
| Boxed warning | Yes | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 8 | 9 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 121,010 | 41,179 |
| DEA schedule | CIV | 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?
Diazepam label, drug interactionsCentrally Acting Agents If Valium is to be combined with other centrally acting agents, careful consideration should be given to the pharmacology of the agents employed particularly with compounds that may potentiate or be potentiated by the action of Valium, such as phenothiazines, antipsychotics, anxiolytics/sedatives, hypnotics, anticonvulsants, narcotic analgesics, anesthetics, sedative antihistamines …
Source: FDA drug labels via openFDA
What next?
- Alternatives to diazepam
- every medicine labeled for the same conditions