MDMA (3,4-Methylenedioxymethamphetamine, "Ecstasy") produces tachycardia, hypertension, hyperthermia, and other acute adverse effects. Ecstasy use has also been associated with rare cardio- and cerebrovascular complications. The role of beta-blockers in the treatment of cardiovascular and adverse effects of MDMA is unknown.

We investigated the interactive effects of the beta-blocker pindolol (20 mg) with MDMA (1.6 mg/kg) on heart rate, blood pressure, body temperature, and adverse effects in a double-blind placebo-controlled study in 16 healthy subjects.

Inclusion Criteria:

• Sufficient understanding of the German language
• Subjects understand the procedures and the risks associated with the study
• Participants must be willing to adhere to the protocol and sign the consent form
• Participants must be willing to refrain from taking illicit psychoactive substances during the study.
• Participants must be willing to drink only alcohol-free liquids and no xanthine-containing liquids after midnight of the evening before the study session.
• Participants must be willing not to drive a traffic vehicle in the evening of the study day.
• Body mass index: 18-25 kg/m2

Exclusion Criteria:

• Chronic or acute medical condition including clinically relevant abnormality in physical exam, laboratory values, or ECG. In particular: Hypertension (>140/90 mmHg). Personal or first-grade history of seizures. Cardiac or neurological disorder.
• Current or previous psychotic or affective disorder
• Psychotic or affective disorder in first-degree relatives
• Prior illicit drug use (except THC-containing products) more than 5 times or any time within the previous 2 months.
• Participation in another clinical trial (currently or within the last 30 days)
• Use of medications that are contraindicated or otherwise interfere with the effects of the study medications.