Two medicines, side by side
Methocarbamol vs diazepam
Methocarbamol and diazepam are both labeled for muscle spasms and spasticity. Drugs@FDA records approvals of methocarbamol since 1957 and of diazepam since 1963. Pharmacies paid $0.0395 per methocarbamol 500 mg tablet and $0.0283 per diazepam 10 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. In FDA's classes, methocarbamol is a muscle relaxant and diazepam a benzodiazepine.
Check it at the source: the methocarbamol FDA label on DailyMed (effective March 17, 2026); the diazepam FDA label on DailyMed (effective August 11, 2026).
Highlights of the methocarbamol record
Methocarbamol (Robaxin) · label of March 17, 2026
Used for
From the label: indicationsMethocarbamol is indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomfort associated with acute, painful musculoskeletal conditions. The mode of action of methocarbamol has not been clearly identified, but may be related to its sedative properties. Methocarbamol does not directly relax tense skeletal muscles in man.
On the market
- Earliest approval on file
- July 16, 1957
- Generic labelers
- 65 labelers
- Pharmacy cost
- $0.0395 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 6
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
Source: FDA drug labels via openFDA (Methocarbamol label of March 17, 2026, Diazepam label of August 11, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do methocarbamol and diazepam differ on the record?
In FDA's classes, methocarbamol is a muscle relaxant and diazepam a benzodiazepine.
Half-life, in each label's words: Methocarbamol, “Pharmacokinetics In healthy volunteers, the plasma clearance of methocarbamol ranges between 0.20 and 0.80 L/h/kg, the …”; Diazepam, “The initial distribution phase has a half-life of approximately 1 hour, although it may range up to >3 hours.”
Only the diazepam label carries a boxed warning.
Generics: methocarbamol since 1974; diazepam since 1985 (Drugs@FDA).
DEA schedule: methocarbamol none; diazepam CIV.
| Methocarbamol | Diazepam | |
|---|---|---|
| Labeled for | Muscle spasms and spasticity | Anxiety, Muscle spasms and spasticity |
| Pharmacologic class | Muscle Relaxant | Benzodiazepine |
| How it works (label) | of methocarbamol in humans has not been established, but may be due to general central nervous system (CNS) depression. It has no direct action on the contractile mechanism of striated muscle, the motor end plate or the nerve fiber. | n/a |
| Half-life (label) | Pharmacokinetics In healthy volunteers, the plasma clearance of methocarbamol ranges between 0.20 and 0.80 L/h/kg, the mean plasma elimination half-life ranges between 1 and 2 hours, and the plasma protein binding … | The initial distribution phase has a half-life of approximately 1 hour, although it may range up to >3 hours. |
| Earliest approval on file (Drugs@FDA) | July 16, 1957 | November 15, 1963 |
| First generic approved | October 22, 1974 | September 4, 1985 |
| Generic labelers (NDC) | 65 labelers | 45 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0395 per tablet (Methocarbamol 500 mg tablet) | $0.0283 per tablet (Diazepam 10 mg tablet) |
| 12-month price change | +6% | -5% |
| Boxed warning | No | Yes |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 6 | 8 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 22,591 | 121,010 |
| DEA schedule | none | CIV |
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?
Methocarbamol label, warningsWARNINGS Since methocarbamol may possess a general CNS depressant effect, patients receiving methocarbamol tablets should be cautioned about combined effects with alcohol and other CNS depressants.
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 methocarbamol
- every medicine labeled for the same conditions