The term ‘Ca²⁺ channel α₂δ ligands' has recently been applied to an evolving drug class that includes gabapentin (Neurontin^®) and pregabalin (Lyrica^®), and reflects significant progress over the past decade in elucidating the mechanism of action of these drugs: a novel, specific action at one of the subunits constituting voltage-sensitive Ca²⁺ channels. Binding of these ligands to the α₂δ subunit is considered to explain their usefulness in treating several clinical disorders, including epilepsy, pain from diabetic neuropathy, postherpetic neuralgia and fibromyalgia, and generalized anxiety disorder. The evidence indicates a relationship between α₂δ subunit binding and the modulation of processes that subserve neurotransmission. This modulation is characterized by a reduction of the excessive neurotransmitter release that is observed in certain neurological and psychiatric disorders.