MDMA impairs response to water intake in healthy volunteers

Summary

MDMA (ecstasy) use can cause dangerously low blood sodium levels (hyponatremia), especially when people drink too much water. In two double-blind, placebo-controlled studies, healthy volunteers who took MDMA did not show increased levels of the hormone that normally regulates water balance (ADH or copeptin), but their blood sodium dropped more than with placebo when they drank standardized amounts of water. Women tended to have lower baseline sodium, but this did not significantly interact with MDMA. The findings indicate that consuming hypotonic fluids during MDMA use poses a significant risk of hyponatremia, which should be anticipated and managed in clinical and recreational settings.

Study at a glance

Abstract

Abstract Hyponatremia is a serious complication of 3,4-methylenedioxymethamphetamine (MDMA) use. We investigated potential mechanisms in two double-blind, placebo-controlled studies. In study 1, healthy drug-experienced volunteers received MDMA or placebo alone and in combination with the alpha-1 adrenergic inverse agonist prazosin, used as a positive control to release antidiuretic hormone (ADH). In study 2, volunteers received MDMA or placebo followed by standardized water intake. MDMA lowered serum sodium, but did not increase ADH or copeptin, although the control prazosin did increase ADH. Water loading reduced serum sodium more after MDMA than after placebo. There was a trend for women to have lower baseline serum sodium than men, but there were no significant interactions with drug condition. Combining studies, MDMA potentiated the ability of water to lower serum sodium. Thus, hyponatremia appears to be a significant risk when hypotonic fluids are consumed during MDMA use. Clinical trials and events where MDMA use is common should anticipate and mitigate this risk.