Orphenadrine citrate is a non-competitive NMDA-type glutamate antagonist which acts centrally as an anticholinergic and non-opioid analgesic (Clark 2002).
Casale et al. (1995) were able to demonstrate a significant reduction of spasticity (p<0.0001) as measured by Ashworth in favour of orphenadrine citrate vs. placebo. This anti-spasmodic effect was demonstrated by an increased flexion reflex threshold as early as 30 minutes post administration. The authors suggest that this drug, given its immediate action, could be used as a preparatory solution for physical therapy sessions in spastic patients and given its known side effect profile, this treatment may be appropriate for short term application.
There is limited level 1b evidence from a single RCT supporting the anti-spastic action of intravenous orphenadrine citrate. Father confirmatory research is needed to support its use.
- Orphenadrine citrate may reduce spasticity in SCI but additional confirmatory research is needed.