Diphenidol-d10 is intended for use as an internal standard for the quantification of diphenidol by GC- or LC-MS. Diphenidol is an antagonist of muscarinic acetylcholine receptors (mAChRs; Kis = 0.43, 2.8, 1.1, 0.91, and 1.28 µM in CHO cell membranes expressing M1-5 receptors, respectively).1 It also inhibits Kv channels in Neuro2A cells (IC50 = 28.2 µM), as well as L-type voltage-gated calcium channels in differentiated NG 108-15 cells in a concentration-dependent manner.2 Microiontophoretic application of diphenidol inhibits rotation-induced firing of medial vestibular nucleus neurons in a cat model of vertigo.3 Diphenidol (3.2 mg/kg, i.v.) prevents apomorphine-induced emesis in dogs.4 Formulations containing diphenidol have been used in the treatment of vertigo and as antiemetics.
1.Varoli, L., Andreani, A., Burnelli, S., et al.Diphenidol-related diamines as novel muscarinic M4 receptor antagonistsBioorg. Med. Chem. Lett.18(9)2972-2976(2008) 2.Leung, Y.M., Wong, K.L., Cheng, K.S., et al.Inhibition of voltage-gated K+ channels and Ca2+ channels by diphenidolPharmacol. Rep.64(3)739-744(2012) 3.Kawabata, A., Sasa, M., Kishimoto, T., et al.Effects of anti-vertigo drugs on medial vestibular nucleus neurons activated by horizontal rotationJpn. J. Pharmacol.55(1)101-106(1991) 4.Nakayama, H., Yamakuni, H., Nakayama, A., et al.Diphenidol has no actual broad antiemetic activity in dogs and ferretsJ. Pharmacol. Sci.96(3)301-306(2004)