Stable heavy isotopes of hydrogen, carbon, and other elements have been incorporated into drug molecules, largely as tracers for quantitation during the drug development process. Deuteration has gained attention because of its potential to affect the pharmacokinetic and metabolic profiles of drugs[1].
References:
[1]. Russak EM, et al. Impact of Deuterium Substitution on the Pharmacokinetics of Pharmaceuticals. Ann Pharmacother. 2019;53(2):211-216.
[2]. Rudoy, C.A. and E.J. Van Bockstaele, Betaxolol, a selective beta(1)-adrenergic receptor antagonist, diminishes anxiety-like behavior during early withdrawal from chronic cocaine administration in rats. Prog Neuropsychopharmacol Biol Psychiatry, 2007. 31(5
[3]. Lesar, T.S., Comparison of ophthalmic beta-blocking agents. Clin Pharm, 1987. 6(6): p. 451-63.