RX 67668

IC50: 5 μM (acetylcholinesterase) and 5 μM (butyrylcholinesterase)

RX 67668 (1-4 mg/kg; i.p.) reduces by half the dose of methacholine necessary to produce red tears, whilst RX 67668 (7-2 mg/kg s.c.) is necessary to reduce the pupil diameter of the mouse to 50% of the control value.
Rat anterior tibialis preparation of the cat tibialis preparation demonstrates that RX 67668 (0.3-1.0 mg/kg; i.v.) is effective in reversing tubocurarine-induced muscle blockade.