2-Amino-5-Chlorobenzoxazole (McN-485,Flexin),A Long-Acting Spinal Cord Depressant. ∗

Summary

McN-485 (Flexin) has been shown to produce selective depression of polysynaptic spinal reflexes at lower does then those required to block monosynaptic reflexes. In much higher doses, it inhibits the response of indirectly stimulated skeletal muscle. In these respects it resembles the other five “spinal cord depressants” tested. However, its duration of action is extremely protracted, as observed previously in unanesthetized animals (10), and its potency was found to be considerably greater than those of the other two long-acting drugs tested. In view of its reported low toxicity and minimum of side-effects, it appears to possess desirable properties as a therapeutic agent of this class.