Heat Makes Ecstasy Drugs a Greater Risk
Credit: Young people having fun dancing at party. via Shutterstock

A dose of the drug Ecstasy that is not normally deadly could turn fatal when taken in a hot, crowded setting, a new study in rats suggests.

Researchers have thought ecstasy, or MDMA, was fatal only in high doses, but the new study found that even moderate doses can be lethal in warm settings that simulate the crowded social venues where people typically take the drug. Ecstasy may cause the body to overheat by restricting its ability to regulate temperature — a condition called hyperthermia, the researchers said.

"Users tend to believe that [MDMA] is pretty safe when used in moderation and that serious adverse health complications, including pathological hyperthermia, result from contamination of MDMA by other 'more dangerous' drugs," said study researcher Eugene Kiyatkin, a scientist at the National Institute on Drug Abuse. "Contrary to popular opinion, MDMA could become very dangerous even at relatively low or moderate doses," when it is used in a warm, humid environment, Kiyatkin told Live Science.

Kiyatkin and colleagues compared MDMA's effects on male rats in two different environments: The first was a standard lab setting that was cool and quiet; the second was a highly social setting, with hotter temperatures and another rat present. Kiyatkin said the second environment is a more realistic representation of the conditions in which humans typically use MDMA, like parties and raves. [The Drug Talk: 7 New Tips for Today’s Parents]

In a cool environment, MDMA modestly increased the rats' brain and body temperature, and rats varied in how they responded to the drug. But in a warm environment, the same dosage showed a more consistent and noted effect: MDMA increased the rats' brain and body temperatures, causing some rats to die.

The researchers hypothesize that, combined with the pressures of the hot environment, MDMA restricted the rats' ability to eliminate excessive heat from their bodies and properly regulate their temperatures — a cooling mechanism that should be natural to the human and rat body. As a result, the rats' body and brain temperatures rose sharply, causing their main organs to shut down.

Scientists previously linked MDMA-related overheating or hyperthermia to high doses of the drug. Hyperthermia can lead to liver, kidney or cardiovascular system failures, as well as death.

Kiyatkin noted that the presence of another rat also amplified the heating effect in the rats. This could be because social interaction tends to put individuals in a highly emotional state before and after taking the drug. "MDMA is often used in company with other people, which adds to the stressfulness of drug intake," Kiyatkin said. MDMA can also affect the body by increasing heart rate or blood pressure and producing symptoms of muscle tension, nausea, chills and faintness.

In the brain, MDMA prompts a surge in serotonin, a neurotransmitter or chemical messenger that travels across brain cells to help regulate mood, emotions, anxiety, memory and perceptions. A serotonin surge produces the elevated feelings of ecstasy or happiness associated with using MDMA.

The study was published June 4 in the Journal of Neuroscience.