Haloperidol-d4 is intended for use as an internal standard for the quantification of haloperidol by GC- or LC-MS. Haloperidol is a typical antipsychotic and dopamine D2-like receptor antagonist (Kis = 0.6, 0.2, and 22 nM, for D2, D3, and D4 receptors, respectively).1 It also acts as an inverse agonist at dopamine D2 and D3 receptors (IC50s = 0.8 and 0.6 nM, respectively). Haloperidol also binds to α1- and α2- adrenergic and histamine H1 receptors, as well as the serotonin (5-HT) receptor subtypes 5-HT1D and 5-HT2A (Kds = 17, 600, 260, 40, and 61 nM, respectively).2 It inhibits stereotypic behavior induced by apomorphine and amphetamine in rats (ID50s = 0.532 and 0.101 μmol/kg, respectively).3 Haloperidol also inhibits apomorphine-induced decreases in prepulse inhibition of the acoustic startle response in rats in a dose-dependent manner.4 Formulations containing haloperidol have been used in the treatment of schizophrenia and Tourette syndrome.
1.Burstein, E.S., Ma, J., Wong, S., et al.Intrinsic efficacy of antipsychotics at human D2, D3, and D4 dopamine receptors: Identification of the clozapine metabolite N-desmethylclozapine as a D2/D3 partial agonistJ. Pharmacol. Exp. Ther.315(3)1278-1287(2005) 2.Richelson, E., and Souder, T.Binding of antipsychotic drugs to human brain receptors: Focus on newer generation compoundsLife Sci.68(1)29-39(2000) 3.Creese, I., Burt, D.R., and Snyder, S.H.Dopamine receptor binding predicts clinical and pharmacological potencies of antischizophrenic drugsJ. Neuropsychiatry Clin. Neurosci.8(2)223-226(1996) 4.Swerdlow, N.R., and Geyer, M.A.Clozapine and haloperidol in an animal model of sensorimotor gating deficits in schizophreniaPharmacol. Biochem. Behav.44(3)741-744(1993)