Sodium lactate infusion, panic attacks, and ionized calcium.

The ability of sodium lactate to precipitate panic attacks in vulnerable individuals has been repeatedly demonstrated, although its mechanism of action is unknown. Pitts and McClure hypothesized that the panicogenic effect of sodium lactate was due to its induction of a peripheral hypocalcemia via the complexing of infused lactate ions with extracellular ionized calcium. In the current study, serial ionized calcium measurements during lactate infusion are assessed for 22 panic patients who panicked during infusion, 11 panic patients who did not panic during the procedure, and 6 normal controls. Intravenous sodium lactate infusion was found to be associated with a significant decrease in ionized calcium in all groups. No specific association was found between the rate or magnitude of decrease in ionized calcium and the occurrence of a panic attack during the infusion.