TC-2559 idifumarate is a CNS-selective, orally active α4β2 subtype of nicotinic acetylcholine receptor (nAChR) partial agonist with an EC50 of 0.18 μM. It exhibits selectivity for α4β2 receptors over α2β4, α4β4, and α3β4 receptors, with EC50s ranging from 10 to 30 μM. TC-2559 difumarate also demonstrates antinociceptive effects.

TC-2559 difumarate, administered intraperitoneally (i.p.) at dosages ranging from 1-10 mg/kg for mice and 0.3-3 mg/kg for rats, has been observed to reduce nociceptive responses and neuropathic pain effectively. In mice subjected to the formalin test (adult males weighing 15-30g), the compound dose-dependently mitigated both early and late phases of pain induced by formalin injection. Similarly, in adult male SD rats (weighing 200-220g) with chronic constriction injury (CCI), TC-2559 difumarate significantly alleviated pain by reversing the decrease in paw withdrawal threshold in a dose-dependent manner, indicating its potential as an analgesic agent in models of acute and neuropathic pain.