Deuterium (D)

Deuterium is a stable, non-radioactive isotope of hydrogen characterized by a nucleus containing one proton and one neutron [8, 12]. Although it is not a traditional therapeutic target like a receptor or enzyme, it is a critical component in medicinal chemistry utilized through a strategy known as the "deuterium switch" [1, 15]. This approach leverages the kinetic isotope effect (KIE), where the carbon-deuterium bond is stronger than the carbon-hydrogen bond, thereby slowing down the rate of metabolic degradation by enzymes such as cytochrome P450 [8, 11]. The primary clinical benefits include improved pharmacokinetic stability, extended drug half-life, and a reduction in the formation of toxic or unwanted metabolites [13, 17]. Notable examples of FDA-approved deuterated therapeutics include deutetrabenazine for Huntington's disease and deucravacitinib for plaque psoriasis [13, 18, 19]. While deuterium is naturally present in trace amounts, systemic replacement of body water with high concentrations of deuterium oxide (heavy water) can be toxic to eukaryotes by disrupting mitosis and essential biochemical equilibria [2, 3, 16].

Other names

Heavy hydrogenHydrogen-22HDeuterium atomDeuteron

Modification of metabolic stability and pharmacokinetic profiles via the primary kinetic isotope effect (KIE), which strengthens carbon-deuterium bonds compared to carbon-hydrogen bonds, thereby slowing enzymatic degradation and altering metabolic pathways [1, 8, 22].