Incorporating the pyrrolidino ring onto the tetrahydroisoquinoline scaffolding markedly improves potency, although this only works for one of the available stereoisomers.

Of these enantiomers, the eutomer is the (6R,10bS) stereoisomer, known as JNJ-39836966, and the distomer, (6S,10bR), is JNJ-39836732 There is some confusion over the nomenclature and cis/trans isomeric relationship at the piperidine ring.

However, there is relatively poor correlation between the in vitro data presented for rats brains vs what was reported at the human transporters.

Elevations in extracellular DA in vivo was higher than expected on the basis of the in vitro transporter affinities.

At saturation, the elevation in synaptic DA was extremely prolific (15 × baseline), whereas SER and NE was ≈ ½ this amount (i.e. 750%).

Like RTI-55 it was made prepared with radiolabelled iodine is an excellent way to scan the brain using positron emission tomography.