Ropivacaine hydrochloride is an inhibitor of K2P (two-pore domain potassium channel) TREK-1 with an IC50 of 402.7 μM.
Ropivacaine hydrochloride shows reversible inhibition of TREK-1 channels in a concentration-dependent manner. The half-maximal inhibitory concentrations (IC50) of Ropivacaine hydrochloride is 402.7±31.8 μM.. Hill coefficient is 0.89 for Ropivacaine hydrochloride[1].
Epidural injections of Ropivacaine hydrochloride (60, 180 and 600 μg) produce immediate and reversible motor paralysis. The motor blockade effect is dose-dependent, with paralysis duration of 4.6, 14.6 and 29.5 mins, respectively. Epidural Ropivacaine hydrochloride sustained release suspension also produces significant blockade of mechanical allodynia and thermal hyperalgesia by 59.5% and 70.9%, respectively (P<0.05). Ropivacaine hydrochloride sustained release suspension also produces a mild antinociception (response to heat stimulus) but longer anti-allodynic and anti-hyperalgesic effects, with biological half-lives of 6.4±2.5 hrs and 6.8±2.9 hrs, respectively (P<0.05). Multiple daily epidural administration of Ropivacaine hydrochloride sustained release suspension prolongs the preemptive effects (P<0.05)[2].
References:
[1]. Shin HW, et al. The inhibitory effects of bupivacaine, levobupivacaine, and ropivacaine on K2P (two-pore domain potassium) channel TREK-1. J Anesth. 2014 Feb;28(1):81-6.
[2]. Li TF, et al. Epidural sustained release ropivacaine prolongs anti-allodynia and anti-hyperalgesia in developing and established neuropathic pain. PLoS One. 2015 Jan 24;10(1):e0117321.