Last reviewed · How we verify

Norgesic (acetylsalicylic acid)

Endo · FDA-approved active Small molecule Verified Quality 82/100

Orphenadrine citrate centrally acts on brain stem to selectively block facilitatory reticular functions.

Norgesic Forte combines orphenadrine citrate, aspirin, and caffeine for symptomatic relief of mild to moderate acute musculoskeletal pain. The orphenadrine component acts centrally on the brain stem reticular formation and possesses anticholinergic properties. Contraindications include glaucoma, urinary/GI obstructions, myasthenia gravis, and hypersensitivity to aspirin or caffeine. Long-term animal studies demonstrated safety with no toxicity or pathological changes observed.

At a glance

Generic nameacetylsalicylic acid
Also known asASA, aspirin, Aspirin, Cardirene, Aspirin(Bayer)
SponsorEndo
Drug classcentrally acting muscle relaxant with anticholinergic properties
Targetreticular formation (brain stem)
ModalitySmall molecule
Therapeutic areaImmunology
PhaseFDA-approved
First approval1950

Mechanism of action

Orphenadrine citrate is a centrally acting compound that selectively blocks facilitatory functions of the reticular formation in the brain stem. The drug does not produce myoneural block or affect crossed extensor reflexes. The exact mode of therapeutic action has not been clearly identified but may be related to its analgesic properties. Orphenadrine also possesses anticholinergic actions. In combination with aspirin and caffeine, chronic administration studies in animals showed no drug-related toxicity, blood or urine changes, or pathological changes.

Approved indications

Boxed warnings

Common side effects

Drug interactions

Patents

PatentExpiryType

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

SourceUsed for
FDA labelMechanism, indications, dosing, boxed warnings, drug interactions
FDA Orange BookPatents + exclusivity

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape: