Depression of spasticity by alpha-adrenergic blockade.

In spastic patients the alpha-adrenergic blocking drug thymoxamine (Opilon Forte) was found capable of depressing most propioceptive reflex parameters within 1 min after intravenous administration. The action seems to be of CNS origin, probably exerted as a depression of spindle stretch sensitivity through descending alpha-adrenergic bulbospinal pathways, but an additional action on the mechanism of presynaptic inhibition is likely. With oral administration, the drug is also capable of depressing distressing clonus, and it is concluded that it deserves further testing as a spasmolytic.