- Alomone Labs Orphenadrine citrate salt inhibits charbacol-induced Ca2+ signal in C6 cells expressing M1 muscarinic receptor.Changes in intracellular Ca2+ were detected via changes in Fluo-3 emission following application. A. Normalized fluorescence before and after co-application (at 20 seconds, see arrow) of 10 µM carbachol and 0-100 µM Orphenadrine citrate salt (#O-100) as indicated. B. Inhibition (as percent of control) of 10 µM carbachol evoked Ca2+ rise, plotted against Orphenadrine citrate salt concentrations.
The group of anticholinergic drugs includes benztropine, biperiden, diphenhydramine, ethopropazine, orphenadrine, procyclidine and trihexyphenidyl. Orphenadrine as the citrate salt is used for the treatment of Parkinson’s disease and in musculoskeletal disorders. It is also used as an analgesic, although its mechanism of action is still unknown1,2. Orphenadrine binds to and modulates the activity of muscarinic receptors of rat brain, with IC50 of 0.37 µM1.
Orphenadrine inhibits NaV channels in a concentration-, voltage- and frequency-dependent manner by binding to the same receptor as the local anesthetics2. Orphenadrine was reported as a muscarinic receptor antagonist, H1 histamine receptor antagonist, muscle relaxant, and inhibits the noradrenergic transporter and blocks the NMDA receptor ion channel3,4.