Molecule

Drug Groups

approved

Description

A muscarinic antagonist used to treat drug-induced parkinsonism and to relieve pain from muscle spasm. [PubChem]

Indication

Indicated for the treatment of Parkinson's disease.

Pharmacology

Orphenadrine is indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomfort associated with acute painful musculoskeletal conditions. Orphenadrine is an anticholinergic with a predominantly central effect and only a weak peripheral effect. In addition, it has mild antihistaminic and local anaesthetic properties. Parkinson's syndrome is the consequence of a disturbed balance between cholinergic and dopaminergic neurotransmission in the basal ganglia caused by a decrease in dopamine. Orphenadrine restores the physiological equilibrium and has a favourable effect on the rigidity and tremor of Parkinson's disease and Parkinsonian syndromes. The effect is somewhat less on bradykinesia.

Toxicity

Oral, mouse LD₅₀ = 100 mg/kg; oral, rat LD₅₀ = 255 mg/kg

Affected Organisms

Biotransformation

Biotransformation occurs mainly in the liver. Pharmacologically active metabolites are N-demethyl orphenadrine and N,N-didemethyl orphenadrine.

Absorption

Orphenadrine is almost completely absorbed in the gastrointestinal tract.

Half Life

13-20 hours

Protein Binding

95%

References

External Links