Seroquel/Quetiapine (Give me a calmative!)

Seroquel antagonizes serotonin, dopamine, and histamine, but it doesn't look a whole lot like any of these:

The benzothiazepene (benzene fused to the seven-membered ring containing nitrogen and sulfur) ring system bears a little resemblance to the benzodiazepines, the class to which Valium belongs, but sulfur and nitrogen are completely different kettles of fish from almost every standpoint - not to mention the rest of the ligand, particularly the piperazine (six-membered ring containing two nitrogens) moiety.

Seroquel finds use as an antipsychotic, along with numerous off-label uses.