B-HT 920 is a full agonist at both pre- and postsynaptic D-2 dopamine receptors.

Stimulation of presynaptic D-2 dopamine receptors by B-HT 920 or by apomorphine inhibited the synthesis of dopamine in the corpus striatum of gammabutyrolactone-treated mice to about the same extent. Stimulation of postsynaptic D-2 dopamine receptors by B-HT 920 given in combination with the D-1 receptor agonist SKF38393 enhanced the motor activity of reserpine-treated mice at least as much as observed following the combined D-1/D-2 receptor agonist apomorphine. Since B-HT 920 is as effective as apomorphine in these models, B-HT 920 appears to be a full agonist at both pre- and post-synaptic D-2 dopamine receptors.