Orphenadrine citrate is a centrally acting (brain stem) compound which in animals selectively blocks facilitatory functions of the reticular formation.
Orphenadrine does not produce myoneural block, nor does it affect crossed extensor reflexes.
Orphenadrine prevents nicotine-induced convulsions but not those produced by strychnine.Chronic administration of Norgesic to dogs and rats has revealed no drug-related toxicity.
No blood or urine changes were observed, nor were there any macroscopic or microscopic pathological changes detected.
Extensive experience with combinations containing aspirin and caffeine has established them as safe agents.
The addition of orphenadrine citrate does not alter the toxicity of aspirin and caffeine.The mode of therapeutic action of orphenadrine has not been clearly identified, but may be related to its analgesic properties.Orphenadrine citrate also possesses anticholinergic actions.
Symptomatic relief of mild to moderate pain of acute musculoskeletal disorders.The orphenadrine component 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 orphenadrine has not been clearly identified, but may be related to its analgesic properties.Norgesic and Norgesic Forte do not directly relax tense skeletal muscles in man.
Because of the mild anticholinergic effect of orphenadrine, Norgesic or Norgesic Forte should not be used in patients with glaucoma, pyloric or duodenal obstruction, achalasia, prostatic hypertrophy or obstructions at the bladder neck.Norgesic or Norgesic Forte is also contraindicated in patients with myasthenia gravis and in patients known to be sensitive to aspirin or caffeine.The drug is contraindicated in patients who have demonstrated a previous hypersensitivity to the drug.
Reye's Syndrome may develop in individuals who have chicken pox, influenza, or flu symptoms.
Some studies suggest a possible association between the development of Reye's Syndrome and the use of medicines containing salicylate or aspirin.Norgesic and Norgesic Forte contain aspirin and therefore are not recommended for use in patients with chicken pox, influenza, or flu symptoms.Norgesic and Norgesic Forte may impair the ability of the patient to engage in potentially hazardous activities such as operating machinery or driving a motor vehicle; ambulatory patients should therefore be cautioned accordingly.Aspirin should be used with extreme caution in the presence of peptic ulcers and coagulation abnormalities.