Randomised, double-blind, placebo-controlled crossover Phase I study (n=16) testing pre-treatment with doxazosin versus placebo on physiological and subjective responses to a single oral MDMA 125 mg dose in healthy volunteers.
This randomized double-blind placebo-controlled crossover study in 16 healthy volunteers tests whether alpha1-adrenergic blockade with doxazosin attenuates the cardiovascular and subjective effects of MDMA (single oral 125 mg).
Doxazosin is given as a pre-treatment regimen across three days before each MDMA session; subjective and cardiovascular measures are recorded repeatedly and plasma samples collected for pharmacokinetics.
Primary outcome focuses on blood pressure response; secondary measures include heart rate, subjective effects and adverse events.
Randomised double-blind placebo-controlled crossover with four experimental sessions; all conditions tested within subjects.
Single oral MDMA 125 mg.
Doxazosin regimen: 3 days before (-64h) 4 mg PO; 2 days before (-40h) 8 mg PO; 1 day before (-16h) 8 mg PO.
Capsules identical to MDMA or doxazosin.
This study assessed the effects of the α₁-noradrenergic receptor antagonist, doxazosin (8mg/day for 3 days), on the acute response to MDMA (125mg) in healthy subjects (n=16). Doxazosin reduced MDMA-induced elevations in blood pressure, and body temperature, and moderately attenuated positive mood but enhanced tachycardia associated with MDMA.