Effects of MDMA alone and after pretreatment with reboxetine, duloxetine, clonidine, carvedilol, and doxazosin on pupillary light reflex

This study analysed data from five separate clinical trials (n=80) that explored the effects of MDMA on pupillary light reflex and the effects following pretreatment with reboxetine, duloxetine, clonidine, carvedilol, and doxazosin, respectively. MDMA produced mydriasis, prolonged the latency, reduced the response to light and shortened the recovery time and this impairment returned to normal 6 hours post-treatment. Only reboxetine and duloxetine interacted with the effects of MDMA on pupillary function.

Abstract

Rationale: Pupillometry can be used to characterize autonomic drug effects.

Objective: This study was conducted to determine the autonomic effects of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy), administered alone and after pretreatment with reboxetine, duloxetine, clonidine, carvedilol, and doxazosin, on pupillary function.

Methods: Infrared pupillometry was performed in five placebo-controlled randomized studies. Each study included 16 healthy subjects (eight men, eight women) who received placebo-MDMA (125 mg), placebo-placebo, pretreatment-placebo, or pretreatment-MDMA using a crossover design.

Results: MDMA produced mydriasis, prolonged the latency, reduced the response to light and shortened the recovery time. The impaired reflex response was associated with subjective, cardiostimulant, and hyperthermic drug effects and returned to normal within 6 h after MDMA administration when plasma MDMA levels were still high. Mydriasis was associated with changes in plasma MDMA concentration over time and longer-lasting. Both reboxetine and duloxetine interacted with the effects of MDMA on pupillary function. Clonidine did not significantly reduce the mydriatic effects of MDMA, although it produced miosis when administered alone. Carvedilol and doxazosin did not alter the effects of MDMA on pupillary function.

Conclusions: The MDMA-induced prolongation of the latency to and reduction of light-induced miosis indicate indirect central parasympathetic inhibition, and the faster recovery time reflects an increased sympathomimetic action. Both norepinephrine and serotonin mediate the effects of MDMA on pupillary function. Although mydriasis is lasting and mirrors the plasma concentration-time curve of MDMA, the impairment in the reaction to light is associated with the subjective and other autonomic effects of MDMA and exhibits acute tolerance.”

Authors: Cedric M. Hysek & Matthias E. Liechti

Study details

Compounds studied
MDMA

Topics studied
Neuroscience

Study characteristics
Placebo-Controlled Double-Blind Randomized Re-analysis

Participants
80 Humans

Authors

Authors associated with this publication with profiles on Blossom

Matthias Liechti
Matthias Emanuel Liechti is the research group leader at the Liechti Lab at the University of Basel.

Institutes

Institutes associated with this publication

University of Basel
The University of Basel Department of Biomedicine hosts the Liechti Lab research group, headed by Matthias Liechti.

Compound Details

The psychedelics given at which dose and how many times

MDMA 125 mg | 1x

Linked Clinical Trial

Interaction Between Reboxetine and 3,4-Methylenedioxymethamphetamine: Pharmacodynamics (PD) and Pharmacokinetics (PK)
This study evaluates the interacting effehe selective norepinephrine transporter inhibitor reboxetine on the subjective and cardiovascular stimulant effects of MDMA in healthy volunteers.

Interaction Between Duloxetine and 3,4-Methylenedioxymethamphetamine (MDMA, Ecstasy)
The purpose of this study is to determinate the effect of a pre-treatment with the combined serotonin (5-HT) and norepinephrine (NE) transport blocker duloxetine on the pharmacodynamics and pharmacokinetics of 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy"). The investigators hypothesize that duloxetine will attenuate the subjective and cardiovascular response to MDMA.

Pharmacological Interaction Between Clonidine and Methylenedioxymethamphetamine (MDMA)
The purpose of this study is to determinate the effect of a pre-treatment with centrally acting alpha2-receptor agonist clonidine on the pharmacodynamics and pharmacokinetics of 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy"). The investigators hypothesize that clonidine will attenuate the subjective and cardiovascular response to MDMA.

Pharmacological Interaction Between Doxazosin and Methylenedioxymethamphetamine (MDMA)
The purpose of this study is to determinate the effect of a pre-treatment with doxazosin, a alpha1-adrenergic receptor blocker, on the pharmacodynamics and pharmacokinetics of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy"). The investigators hypothesize that doxazosin will attenuate the cardiovascular and subjective response to MDMA.

Pharmacological Interaction Between Carvedilol and Methylenedioxymethamphetamine (MDMA)
The purpose of this study is to determinate the effect of a pre-treatment with carvedilol, a alpha- and beta-adrenergic receptor blocker, on the pharmacodynamics and pharmacokinetics of 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy"). The investigators hypothesize that carvedilol will attenuate the cardiovascular and subjective response to MDMA.