In Vivo: Tigloidine hydrobromide (20-60 mg/kg, i.p.) fails to protect the mice against the lethal effect of physostigmine, but at 100 mg/kg and above, it protects 80% of the animals against the lethal effect. Tigloidine markedly prevents tremor and salivation produced by tremorine at 80-100 mg/kg, but fails to prevent these effects in doses up to 40 mg/kg. Tigloidine (up to 100 mg/kg, i.p) does not significantly affects reserpine and tetrabenazine induced sedation and ptosis in mice. Tigloidine (25-50 mg/kg, i.p.) also fails to cause any behavioral changes in the cats.