Sumatriptan drug, molecular model. This drug, marketed as Imitrex, Imigran and Imigran Recovery, is used to treat migraine headaches. Migraine is a painful neurological condition thought to be caused by abnormal levels of serotonin, a neurotransmitter that contributes to the regulation of mood, sleep and appetite. As sumatriptan has a similar structure to serotonin, it can bind to a type of serotonin receptor and activate the pathways. This levels out the erratic levels of serotonin that often precede a migraine. Atoms in this model are represented by coloured spheres; carbon is turquoise, hydrogen is white, oxygen is orange, nitrogen is purple and sulphur is green.